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ACCURATE SPEEDOMETER?
ACCURATE SPEEDOMETER?
Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
gearing, and D30 front/35 rear. I recently upgraded my tires from the
stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
for a reliable way to tell if my speedometer is off at all with the
tire upgrade. I do not have access to a GPS system. What I HAVE done
is to use the tripometer (with tenths), and hold steady at 60 mph (my
speedometer said 60) for one mile while watching my clock. I am
EXTREMELY close to going 1 mile in 1 minute by using this method. Is
this reliable to tell whether or not my speedometer is dead on? I
have NOT changed the speedometer gear yet, or had the computer changed
to reflect the larger sized tires. Also, I am not using my OD (6th)
much on the highway, but when I get up to 65 (the speedometer says
65), I am running at about 2500 rpms in 5th. Is this bad, or should I
be shifting into the OD (6th)? I do fine with 1st through 5th. Just
not sure what speed or what rpms I should be using 6th. Any help is
really appreciated.
Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
gearing, and D30 front/35 rear. I recently upgraded my tires from the
stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
for a reliable way to tell if my speedometer is off at all with the
tire upgrade. I do not have access to a GPS system. What I HAVE done
is to use the tripometer (with tenths), and hold steady at 60 mph (my
speedometer said 60) for one mile while watching my clock. I am
EXTREMELY close to going 1 mile in 1 minute by using this method. Is
this reliable to tell whether or not my speedometer is dead on? I
have NOT changed the speedometer gear yet, or had the computer changed
to reflect the larger sized tires. Also, I am not using my OD (6th)
much on the highway, but when I get up to 65 (the speedometer says
65), I am running at about 2500 rpms in 5th. Is this bad, or should I
be shifting into the OD (6th)? I do fine with 1st through 5th. Just
not sure what speed or what rpms I should be using 6th. Any help is
really appreciated.
Re: Re: ACCURATE SPEEDOMETER?
On Mon, 17 Sep 2007 08:38:45 -0500, c <c@me.org> wrote:
>Tracie wrote:
>> Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
>> gearing, and D30 front/35 rear. I recently upgraded my tires from the
>> stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
>> for a reliable way to tell if my speedometer is off at all with the
>> tire upgrade. I do not have access to a GPS system. What I HAVE done
>> is to use the tripometer (with tenths), and hold steady at 60 mph (my
>> speedometer said 60) for one mile while watching my clock. I am
>> EXTREMELY close to going 1 mile in 1 minute by using this method. Is
>> this reliable to tell whether or not my speedometer is dead on? I
>> have NOT changed the speedometer gear yet, or had the computer changed
>> to reflect the larger sized tires. Also, I am not using my OD (6th)
>> much on the highway, but when I get up to 65 (the speedometer says
>> 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
>> be shifting into the OD (6th)? I do fine with 1st through 5th. Just
>> not sure what speed or what rpms I should be using 6th. Any help is
>> really appreciated.
>>
>
>The trip odometer should be close. You can also use the mile markers on
>the side of the highways assuming those are correct in your area. I was
>told by a local road worker in Wisconsin that they are very accurate,
>but that may vary by states.
>
>As far as 6th gear is concerned, using only 5th gear will cause more
>engine wear, but it may or may not hurt fuel economy. The only thing to
>do there is to test it out. I would think that with the small increase
>in tire diameter, you should still be using 6th gear. You do have a very
>high gear in your axles, so it is probably worth testing.
>
>Chris
Your speedo with be off a good bit. You will be going faster than it
records. With 65 indicated you will be doing about 73 MPH. With 3.07
gear it has got to be a bit of a slug at times too with 31's. Below is
a link where you can run some numbers yourself
http :// www .snoman,com /HTML/axlecalc_5a.html
-----------------
TheSnoMan,com
On Mon, 17 Sep 2007 08:38:45 -0500, c <c@me.org> wrote:
>Tracie wrote:
>> Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
>> gearing, and D30 front/35 rear. I recently upgraded my tires from the
>> stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
>> for a reliable way to tell if my speedometer is off at all with the
>> tire upgrade. I do not have access to a GPS system. What I HAVE done
>> is to use the tripometer (with tenths), and hold steady at 60 mph (my
>> speedometer said 60) for one mile while watching my clock. I am
>> EXTREMELY close to going 1 mile in 1 minute by using this method. Is
>> this reliable to tell whether or not my speedometer is dead on? I
>> have NOT changed the speedometer gear yet, or had the computer changed
>> to reflect the larger sized tires. Also, I am not using my OD (6th)
>> much on the highway, but when I get up to 65 (the speedometer says
>> 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
>> be shifting into the OD (6th)? I do fine with 1st through 5th. Just
>> not sure what speed or what rpms I should be using 6th. Any help is
>> really appreciated.
>>
>
>The trip odometer should be close. You can also use the mile markers on
>the side of the highways assuming those are correct in your area. I was
>told by a local road worker in Wisconsin that they are very accurate,
>but that may vary by states.
>
>As far as 6th gear is concerned, using only 5th gear will cause more
>engine wear, but it may or may not hurt fuel economy. The only thing to
>do there is to test it out. I would think that with the small increase
>in tire diameter, you should still be using 6th gear. You do have a very
>high gear in your axles, so it is probably worth testing.
>
>Chris
Your speedo with be off a good bit. You will be going faster than it
records. With 65 indicated you will be doing about 73 MPH. With 3.07
gear it has got to be a bit of a slug at times too with 31's. Below is
a link where you can run some numbers yourself
http :// www .snoman,com /HTML/axlecalc_5a.html
-----------------
TheSnoMan,com
Re: Re: ACCURATE SPEEDOMETER?
On Mon, 17 Sep 2007 08:38:45 -0500, c <c@me.org> wrote:
>As far as 6th gear is concerned, using only 5th gear will cause more
>engine wear
On a foot note, I do not know were this myth started. The engine is
not going to wear out any sooner in 5th and may actually last longer
if 6th is so tall that engine lugs. A few extra RPM never hurt any
engine and lower RPM lugging is potentailly far more damaging and
tough on bearings.
-----------------
TheSnoMan,com
On Mon, 17 Sep 2007 08:38:45 -0500, c <c@me.org> wrote:
>As far as 6th gear is concerned, using only 5th gear will cause more
>engine wear
On a foot note, I do not know were this myth started. The engine is
not going to wear out any sooner in 5th and may actually last longer
if 6th is so tall that engine lugs. A few extra RPM never hurt any
engine and lower RPM lugging is potentailly far more damaging and
tough on bearings.
-----------------
TheSnoMan,com
Re: ACCURATE SPEEDOMETER?
SnoMan wrote:
> On Mon, 17 Sep 2007 08:38:45 -0500, c <c@me.org> wrote:
>
>> As far as 6th gear is concerned, using only 5th gear will cause more
>> engine wear
>
>
> On a foot note, I do not know were this myth started. The engine is
> not going to wear out any sooner in 5th and may actually last longer
> if 6th is so tall that engine lugs. A few extra RPM never hurt any
> engine and lower RPM lugging is potentailly far more damaging and
> tough on bearings.
> -----------------
> TheSnoMan,com
Um, your statement is quite wrong. For instance, overdrive on my truck
reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
sooner if I choose to never use it. I will agree with you on the lugging
part, especially if it causes pinging, but no, I will not sit here and
agree with you that my engine will last just as long turning 3000 RPM as
it does turning 2100 RPM. That's insane.
Chris
SnoMan wrote:
> On Mon, 17 Sep 2007 08:38:45 -0500, c <c@me.org> wrote:
>
>> As far as 6th gear is concerned, using only 5th gear will cause more
>> engine wear
>
>
> On a foot note, I do not know were this myth started. The engine is
> not going to wear out any sooner in 5th and may actually last longer
> if 6th is so tall that engine lugs. A few extra RPM never hurt any
> engine and lower RPM lugging is potentailly far more damaging and
> tough on bearings.
> -----------------
> TheSnoMan,com
Um, your statement is quite wrong. For instance, overdrive on my truck
reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
sooner if I choose to never use it. I will agree with you on the lugging
part, especially if it causes pinging, but no, I will not sit here and
agree with you that my engine will last just as long turning 3000 RPM as
it does turning 2100 RPM. That's insane.
Chris
Re: Re: ACCURATE SPEEDOMETER?
On Mon, 17 Sep 2007 12:52:55 -0500, c <c@me.org> wrote:
>Um, your statement is quite wrong. For instance, overdrive on my truck
>reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
>sooner if I choose to never use it. I will agree with you on the lugging
>part, especially if it causes pinging, but no, I will not sit here and
>agree with you that my engine will last just as long turning 3000 RPM as
>it does turning 2100 RPM. That's insane.
Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
that when 220K with a 3000 to 3500 RPM cruise and more and was using
a quart maybe every 3500 miles then. Also true RPM drop is determined
by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
4L60 or .69 on a Ally 5 speed)
-----------------
TheSnoMan,com
On Mon, 17 Sep 2007 12:52:55 -0500, c <c@me.org> wrote:
>Um, your statement is quite wrong. For instance, overdrive on my truck
>reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
>sooner if I choose to never use it. I will agree with you on the lugging
>part, especially if it causes pinging, but no, I will not sit here and
>agree with you that my engine will last just as long turning 3000 RPM as
>it does turning 2100 RPM. That's insane.
Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
that when 220K with a 3000 to 3500 RPM cruise and more and was using
a quart maybe every 3500 miles then. Also true RPM drop is determined
by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
4L60 or .69 on a Ally 5 speed)
-----------------
TheSnoMan,com
Re: ACCURATE SPEEDOMETER?
SnoMan wrote:
> On Mon, 17 Sep 2007 12:52:55 -0500, c <c@me.org> wrote:
>
>> Um, your statement is quite wrong. For instance, overdrive on my truck
>> reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
>> sooner if I choose to never use it. I will agree with you on the lugging
>> part, especially if it causes pinging, but no, I will not sit here and
>> agree with you that my engine will last just as long turning 3000 RPM as
>> it does turning 2100 RPM. That's insane.
>
>
> Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
> with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
> excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
> all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
> that when 220K with a 3000 to 3500 RPM cruise and more and was using
> a quart maybe every 3500 miles then. Also true RPM drop is determined
> by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
> 4L60 or .69 on a Ally 5 speed)
> -----------------
> TheSnoMan,com
Well, it just so happens I HAVE a 700R4. Don't come off as the only
person that knows how to figure out gear ratio calculations. Geezus, I
think sometimes you argue just for the sake of arguing.
Chris
SnoMan wrote:
> On Mon, 17 Sep 2007 12:52:55 -0500, c <c@me.org> wrote:
>
>> Um, your statement is quite wrong. For instance, overdrive on my truck
>> reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
>> sooner if I choose to never use it. I will agree with you on the lugging
>> part, especially if it causes pinging, but no, I will not sit here and
>> agree with you that my engine will last just as long turning 3000 RPM as
>> it does turning 2100 RPM. That's insane.
>
>
> Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
> with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
> excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
> all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
> that when 220K with a 3000 to 3500 RPM cruise and more and was using
> a quart maybe every 3500 miles then. Also true RPM drop is determined
> by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
> 4L60 or .69 on a Ally 5 speed)
> -----------------
> TheSnoMan,com
Well, it just so happens I HAVE a 700R4. Don't come off as the only
person that knows how to figure out gear ratio calculations. Geezus, I
think sometimes you argue just for the sake of arguing.
Chris
Re: ACCURATE SPEEDOMETER?
On Mon, 17 Sep 2007 14:53:07 -0400, SnoMan <admin@snoman,com > wrote:
>On Mon, 17 Sep 2007 12:52:55 -0500, c <c@me.org> wrote:
>
>>Um, your statement is quite wrong. For instance, overdrive on my truck
>>reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
>>sooner if I choose to never use it. I will agree with you on the lugging
>>part, especially if it causes pinging, but no, I will not sit here and
>>agree with you that my engine will last just as long turning 3000 RPM as
>>it does turning 2100 RPM. That's insane.
>
>
>Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
>with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
>excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
>all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
>that when 220K with a 3000 to 3500 RPM cruise and more and was using
>a quart maybe every 3500 miles then. Also true RPM drop is determined
>by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
>4L60 or .69 on a Ally 5 speed)
>-----------------
>TheSnoMan,com
Hey Snow, look out! There's another dead horse. Better get your
baseball bat.
--
Old Crow "Yol Bolson!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http :// www .teranews,com
On Mon, 17 Sep 2007 14:53:07 -0400, SnoMan <admin@snoman,com > wrote:
>On Mon, 17 Sep 2007 12:52:55 -0500, c <c@me.org> wrote:
>
>>Um, your statement is quite wrong. For instance, overdrive on my truck
>>reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
>>sooner if I choose to never use it. I will agree with you on the lugging
>>part, especially if it causes pinging, but no, I will not sit here and
>>agree with you that my engine will last just as long turning 3000 RPM as
>>it does turning 2100 RPM. That's insane.
>
>
>Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
>with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
>excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
>all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
>that when 220K with a 3000 to 3500 RPM cruise and more and was using
>a quart maybe every 3500 miles then. Also true RPM drop is determined
>by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
>4L60 or .69 on a Ally 5 speed)
>-----------------
>TheSnoMan,com
Hey Snow, look out! There's another dead horse. Better get your
baseball bat.
--
Old Crow "Yol Bolson!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http :// www .teranews,com
Re: ACCURATE SPEEDOMETER?
On Sep 18, 6:10 am, Old Crow <wallisc...@yahoo,com > wrote:
> On Mon, 17 Sep 2007 14:53:07 -0400, SnoMan <ad...@snoman,com > wrote:
> >On Mon, 17 Sep 2007 12:52:55 -0500, c <c...@me.org> wrote:
>
> >>Um, your statement is quite wrong. For instance, overdrive on my truck
> >>reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
> >>sooner if I choose to never use it. I will agree with you on the lugging
> >>part, especially if it causes pinging, but no, I will not sit here and
> >>agree with you that my engine will last just as long turning 3000 RPM as
> >>it does turning 2100 RPM. That's insane.
>
> >Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
> >with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
> >excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
> >all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
> >that when 220K with a 3000 to 3500 RPM cruise and more and was using
> >a quart maybe every 3500 miles then. Also true RPM drop is determined
> >by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
> >4L60 or .69 on a Ally 5 speed)
> >-----------------
> >TheSnoMan,com
>
> Hey Snow, look out! There's another dead horse. Better get your
> baseball bat.
> --
> Old Crow "Yol Bolson!"
> '82 FLTC-P "Miss Pearl"
> '95 YJ Rio Grande
> BS#133, SENS, TOMKAT, MAMBM
>
> --
> Posted via a free Usenet account from http :// www .teranews,com - Hide quoted text -
>
> - Show quoted text -
Thanks Chris. That was helpful. :)
I will just have to remember to fill my tank with 89 octane instead of
87. Is there much of a difference in effectiveness between the 89 and
93 as far as pinging is concerned?
On Sep 18, 6:10 am, Old Crow <wallisc...@yahoo,com > wrote:
> On Mon, 17 Sep 2007 14:53:07 -0400, SnoMan <ad...@snoman,com > wrote:
> >On Mon, 17 Sep 2007 12:52:55 -0500, c <c...@me.org> wrote:
>
> >>Um, your statement is quite wrong. For instance, overdrive on my truck
> >>reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
> >>sooner if I choose to never use it. I will agree with you on the lugging
> >>part, especially if it causes pinging, but no, I will not sit here and
> >>agree with you that my engine will last just as long turning 3000 RPM as
> >>it does turning 2100 RPM. That's insane.
>
> >Gee how did I put close to 200K and a few 4x4's 20 to 30 years ago
> >with 4.10 and 4.56 gears and no OD???? RPM as long as it is not
> >excessive (like 4000 to 5000 RPM cruises ) will not shorten life at
> >all. 2500 RPM or cruise for a V8 is childs play. How about a Toyota
> >that when 220K with a 3000 to 3500 RPM cruise and more and was using
> >a quart maybe every 3500 miles then. Also true RPM drop is determined
> >by OD ratio and to get a 30% drop you need a .7 (like on a 700R4 or
> >4L60 or .69 on a Ally 5 speed)
> >-----------------
> >TheSnoMan,com
>
> Hey Snow, look out! There's another dead horse. Better get your
> baseball bat.
> --
> Old Crow "Yol Bolson!"
> '82 FLTC-P "Miss Pearl"
> '95 YJ Rio Grande
> BS#133, SENS, TOMKAT, MAMBM
>
> --
> Posted via a free Usenet account from http :// www .teranews,com - Hide quoted text -
>
> - Show quoted text -
Thanks Chris. That was helpful. :)
I will just have to remember to fill my tank with 89 octane instead of
87. Is there much of a difference in effectiveness between the 89 and
93 as far as pinging is concerned?
Re: ACCURATE SPEEDOMETER?
If your pedal is near the metal, your engine is lugging at two grand and
using more gasoline than at a cruising speed of three grand, also fourth is
direct, and doesn't use any gears nor bearing like in overdrive. So it saves
the transmission, too.
God Bless America, Bill O|||||||O
mailto:LWHughes3rd@aol,com http :// www .billhughes,com /
"c" <c@me.org> wrote in message
news:46eebede$0$32530$4c368faf@roadrunner,com ...
>
>
> Um, your statement is quite wrong. For instance, overdrive on my truck
> reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
> sooner if I choose to never use it. I will agree with you on the lugging
> part, especially if it causes pinging, but no, I will not sit here and
> agree with you that my engine will last just as long turning 3000 RPM as
> it does turning 2100 RPM. That's insane.
>
> Chris
--
Posted via a free Usenet account from http :// www .teranews,com
If your pedal is near the metal, your engine is lugging at two grand and
using more gasoline than at a cruising speed of three grand, also fourth is
direct, and doesn't use any gears nor bearing like in overdrive. So it saves
the transmission, too.
God Bless America, Bill O|||||||O
mailto:LWHughes3rd@aol,com http :// www .billhughes,com /
"c" <c@me.org> wrote in message
news:46eebede$0$32530$4c368faf@roadrunner,com ...
>
>
> Um, your statement is quite wrong. For instance, overdrive on my truck
> reduces the RPM by 30% so yeah I am pretty sure my engine will wear out
> sooner if I choose to never use it. I will agree with you on the lugging
> part, especially if it causes pinging, but no, I will not sit here and
> agree with you that my engine will last just as long turning 3000 RPM as
> it does turning 2100 RPM. That's insane.
>
> Chris
--
Posted via a free Usenet account from http :// www .teranews,com
Re: ACCURATE SPEEDOMETER?
Tracie wrote:
> Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> gearing, and D30 front/35 rear. I recently upgraded my tires from the
> stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> for a reliable way to tell if my speedometer is off at all with the
> tire upgrade. I do not have access to a GPS system. What I HAVE done
> is to use the tripometer (with tenths), and hold steady at 60 mph (my
> speedometer said 60) for one mile while watching my clock. I am
> EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> this reliable to tell whether or not my speedometer is dead on? I
> have NOT changed the speedometer gear yet, or had the computer changed
> to reflect the larger sized tires. Also, I am not using my OD (6th)
> much on the highway, but when I get up to 65 (the speedometer says
> 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> not sure what speed or what rpms I should be using 6th. Any help is
> really appreciated.
>
The (ones that have posed here) older TJ speedometers became correct
when 31" tire were put on.
Your mile per minute is a good base to tell it is close.
The only other way is to find a measured mile or a friend with a GPS or
even ask a cop to pace you because 'you just got new tires and don't
want to break the law'. Only a cop's speedometer would be reliable for
this, cars can be off too according to tire size.
I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
highway which I get with my 4th gear. (have 33's and 3.31 gears) That
rpm gives me good throttle control and prevents engine lugging. I also
get a pretty stable 11L/100km or 23 mpg running there.
If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
which makes for the need of the full gas pedal travel to adjust speed or
hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
my gas mileage by at least 5-8 mpg.
You can find out easy. Just compare gas mileages when using only 5th on
the highway and when using 6th mostly. I have one trip I do lots to get
bush camping which is 201 km from gas station to gas station so I have
an easy check point.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http :// www .imagestation,com /album/pictures.html?id!15147590
(More Off Road album links at bottom of the view page)
Tracie wrote:
> Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> gearing, and D30 front/35 rear. I recently upgraded my tires from the
> stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> for a reliable way to tell if my speedometer is off at all with the
> tire upgrade. I do not have access to a GPS system. What I HAVE done
> is to use the tripometer (with tenths), and hold steady at 60 mph (my
> speedometer said 60) for one mile while watching my clock. I am
> EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> this reliable to tell whether or not my speedometer is dead on? I
> have NOT changed the speedometer gear yet, or had the computer changed
> to reflect the larger sized tires. Also, I am not using my OD (6th)
> much on the highway, but when I get up to 65 (the speedometer says
> 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> not sure what speed or what rpms I should be using 6th. Any help is
> really appreciated.
>
The (ones that have posed here) older TJ speedometers became correct
when 31" tire were put on.
Your mile per minute is a good base to tell it is close.
The only other way is to find a measured mile or a friend with a GPS or
even ask a cop to pace you because 'you just got new tires and don't
want to break the law'. Only a cop's speedometer would be reliable for
this, cars can be off too according to tire size.
I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
highway which I get with my 4th gear. (have 33's and 3.31 gears) That
rpm gives me good throttle control and prevents engine lugging. I also
get a pretty stable 11L/100km or 23 mpg running there.
If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
which makes for the need of the full gas pedal travel to adjust speed or
hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
my gas mileage by at least 5-8 mpg.
You can find out easy. Just compare gas mileages when using only 5th on
the highway and when using 6th mostly. I have one trip I do lots to get
bush camping which is 201 km from gas station to gas station so I have
an easy check point.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http :// www .imagestation,com /album/pictures.html?id!15147590
(More Off Road album links at bottom of the view page)
Re: ACCURATE SPEEDOMETER?
On Sep 17, 11:17 am, Mike Romain <roma...@sympatico.ca> wrote:
> Tracie wrote:
> > Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> > gearing, and D30 front/35 rear. I recently upgraded my tires from the
> > stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> > for a reliable way to tell if my speedometer is off at all with the
> > tire upgrade. I do not have access to a GPS system. What I HAVE done
> > is to use the tripometer (with tenths), and hold steady at 60 mph (my
> > speedometer said 60) for one mile while watching my clock. I am
> > EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> > this reliable to tell whether or not my speedometer is dead on? I
> > have NOT changed the speedometer gear yet, or had the computer changed
> > to reflect the larger sized tires. Also, I am not using my OD (6th)
> > much on the highway, but when I get up to 65 (the speedometer says
> > 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> > be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> > not sure what speed or what rpms I should be using 6th. Any help is
> > really appreciated.
>
> The (ones that have posed here) older TJ speedometers became correct
> when 31" tire were put on.
>
> Your mile per minute is a good base to tell it is close.
>
> The only other way is to find a measured mile or a friend with a GPS or
> even ask a cop to pace you because 'you just got new tires and don't
> want to break the law'. Only a cop's speedometer would be reliable for
> this, cars can be off too according to tire size.
>
> I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
> highway which I get with my 4th gear. (have 33's and 3.31 gears) That
> rpm gives me good throttle control and prevents engine lugging. I also
> get a pretty stable 11L/100km or 23 mpg running there.
>
> If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
> which makes for the need of the full gas pedal travel to adjust speed or
> hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
> my gas mileage by at least 5-8 mpg.
>
> You can find out easy. Just compare gas mileages when using only 5th on
> the highway and when using 6th mostly. I have one trip I do lots to get
> bush camping which is 201 km from gas station to gas station so I have
> an easy check point.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http :// www .imagestation,com /album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> - Show quoted text -
So, assuming that my speedometer is correct, running approximately
2500 rpms in 5th gear at 65 mph will NOT hurt my engine or cause
increased engine wear? If I were to shift into OD (6th), what is the
approximate rpms that I should be running so as to not cause lugging
or increased engine wear?
THANKS
On Sep 17, 11:17 am, Mike Romain <roma...@sympatico.ca> wrote:
> Tracie wrote:
> > Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> > gearing, and D30 front/35 rear. I recently upgraded my tires from the
> > stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> > for a reliable way to tell if my speedometer is off at all with the
> > tire upgrade. I do not have access to a GPS system. What I HAVE done
> > is to use the tripometer (with tenths), and hold steady at 60 mph (my
> > speedometer said 60) for one mile while watching my clock. I am
> > EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> > this reliable to tell whether or not my speedometer is dead on? I
> > have NOT changed the speedometer gear yet, or had the computer changed
> > to reflect the larger sized tires. Also, I am not using my OD (6th)
> > much on the highway, but when I get up to 65 (the speedometer says
> > 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> > be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> > not sure what speed or what rpms I should be using 6th. Any help is
> > really appreciated.
>
> The (ones that have posed here) older TJ speedometers became correct
> when 31" tire were put on.
>
> Your mile per minute is a good base to tell it is close.
>
> The only other way is to find a measured mile or a friend with a GPS or
> even ask a cop to pace you because 'you just got new tires and don't
> want to break the law'. Only a cop's speedometer would be reliable for
> this, cars can be off too according to tire size.
>
> I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
> highway which I get with my 4th gear. (have 33's and 3.31 gears) That
> rpm gives me good throttle control and prevents engine lugging. I also
> get a pretty stable 11L/100km or 23 mpg running there.
>
> If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
> which makes for the need of the full gas pedal travel to adjust speed or
> hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
> my gas mileage by at least 5-8 mpg.
>
> You can find out easy. Just compare gas mileages when using only 5th on
> the highway and when using 6th mostly. I have one trip I do lots to get
> bush camping which is 201 km from gas station to gas station so I have
> an easy check point.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http :// www .imagestation,com /album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> - Show quoted text -
So, assuming that my speedometer is correct, running approximately
2500 rpms in 5th gear at 65 mph will NOT hurt my engine or cause
increased engine wear? If I were to shift into OD (6th), what is the
approximate rpms that I should be running so as to not cause lugging
or increased engine wear?
THANKS
Re: ACCURATE SPEEDOMETER?
On Sep 17, 11:26 am, Tracie <brain...@upstate.edu> wrote:
> On Sep 17, 11:17 am, Mike Romain <roma...@sympatico.ca> wrote:
>
>
>
>
>
> > Tracie wrote:
> > > Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> > > gearing, and D30 front/35 rear. I recently upgraded my tires from the
> > > stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> > > for a reliable way to tell if my speedometer is off at all with the
> > > tire upgrade. I do not have access to a GPS system. What I HAVE done
> > > is to use the tripometer (with tenths), and hold steady at 60 mph (my
> > > speedometer said 60) for one mile while watching my clock. I am
> > > EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> > > this reliable to tell whether or not my speedometer is dead on? I
> > > have NOT changed the speedometer gear yet, or had the computer changed
> > > to reflect the larger sized tires. Also, I am not using my OD (6th)
> > > much on the highway, but when I get up to 65 (the speedometer says
> > > 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> > > be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> > > not sure what speed or what rpms I should be using 6th. Any help is
> > > really appreciated.
>
> > The (ones that have posed here) older TJ speedometers became correct
> > when 31" tire were put on.
>
> > Your mile per minute is a good base to tell it is close.
>
> > The only other way is to find a measured mile or a friend with a GPS or
> > even ask a cop to pace you because 'you just got new tires and don't
> > want to break the law'. Only a cop's speedometer would be reliable for
> > this, cars can be off too according to tire size.
>
> > I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
> > highway which I get with my 4th gear. (have 33's and 3.31 gears) That
> > rpm gives me good throttle control and prevents engine lugging. I also
> > get a pretty stable 11L/100km or 23 mpg running there.
>
> > If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
> > which makes for the need of the full gas pedal travel to adjust speed or
> > hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
> > my gas mileage by at least 5-8 mpg.
>
> > You can find out easy. Just compare gas mileages when using only 5th on
> > the highway and when using 6th mostly. I have one trip I do lots to get
> > bush camping which is 201 km from gas station to gas station so I have
> > an easy check point.
>
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> > Canadian Off Road Trips Photos: Non members can still view!
> > Jan/06 http :// www .imagestation,com /album/pictures.html?id=2115147590
> > (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> > - Show quoted text -
>
> So, assuming that my speedometer is correct, running approximately
> 2500 rpms in 5th gear at 65 mph will NOT hurt my engine or cause
> increased engine wear? If I were to shift into OD (6th), what is the
> approximate rpms that I should be running so as to not cause lugging
> or increased engine wear?
>
> THANKS- Hide quoted text -
>
> - Show quoted text -
Oh, nevermind. I think I just answered my own question. : D
I am assuming that the approximate 2500 rpms would apply to the OD
(6th) gear as well to prevent increased engine wear and lugging?
On Sep 17, 11:26 am, Tracie <brain...@upstate.edu> wrote:
> On Sep 17, 11:17 am, Mike Romain <roma...@sympatico.ca> wrote:
>
>
>
>
>
> > Tracie wrote:
> > > Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> > > gearing, and D30 front/35 rear. I recently upgraded my tires from the
> > > stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> > > for a reliable way to tell if my speedometer is off at all with the
> > > tire upgrade. I do not have access to a GPS system. What I HAVE done
> > > is to use the tripometer (with tenths), and hold steady at 60 mph (my
> > > speedometer said 60) for one mile while watching my clock. I am
> > > EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> > > this reliable to tell whether or not my speedometer is dead on? I
> > > have NOT changed the speedometer gear yet, or had the computer changed
> > > to reflect the larger sized tires. Also, I am not using my OD (6th)
> > > much on the highway, but when I get up to 65 (the speedometer says
> > > 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> > > be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> > > not sure what speed or what rpms I should be using 6th. Any help is
> > > really appreciated.
>
> > The (ones that have posed here) older TJ speedometers became correct
> > when 31" tire were put on.
>
> > Your mile per minute is a good base to tell it is close.
>
> > The only other way is to find a measured mile or a friend with a GPS or
> > even ask a cop to pace you because 'you just got new tires and don't
> > want to break the law'. Only a cop's speedometer would be reliable for
> > this, cars can be off too according to tire size.
>
> > I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
> > highway which I get with my 4th gear. (have 33's and 3.31 gears) That
> > rpm gives me good throttle control and prevents engine lugging. I also
> > get a pretty stable 11L/100km or 23 mpg running there.
>
> > If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
> > which makes for the need of the full gas pedal travel to adjust speed or
> > hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
> > my gas mileage by at least 5-8 mpg.
>
> > You can find out easy. Just compare gas mileages when using only 5th on
> > the highway and when using 6th mostly. I have one trip I do lots to get
> > bush camping which is 201 km from gas station to gas station so I have
> > an easy check point.
>
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> > Canadian Off Road Trips Photos: Non members can still view!
> > Jan/06 http :// www .imagestation,com /album/pictures.html?id=2115147590
> > (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> > - Show quoted text -
>
> So, assuming that my speedometer is correct, running approximately
> 2500 rpms in 5th gear at 65 mph will NOT hurt my engine or cause
> increased engine wear? If I were to shift into OD (6th), what is the
> approximate rpms that I should be running so as to not cause lugging
> or increased engine wear?
>
> THANKS- Hide quoted text -
>
> - Show quoted text -
Oh, nevermind. I think I just answered my own question. : D
I am assuming that the approximate 2500 rpms would apply to the OD
(6th) gear as well to prevent increased engine wear and lugging?
Re: ACCURATE SPEEDOMETER?
On Sep 17, 11:34 am, Tracie <brain...@upstate.edu> wrote:
> On Sep 17, 11:26 am, Tracie <brain...@upstate.edu> wrote:
>
>
>
>
>
> > On Sep 17, 11:17 am, Mike Romain <roma...@sympatico.ca> wrote:
>
> > > Tracie wrote:
> > > > Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> > > > gearing, and D30 front/35 rear. I recently upgraded my tires from the
> > > > stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> > > > for a reliable way to tell if my speedometer is off at all with the
> > > > tire upgrade. I do not have access to a GPS system. What I HAVE done
> > > > is to use the tripometer (with tenths), and hold steady at 60 mph (my
> > > > speedometer said 60) for one mile while watching my clock. I am
> > > > EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> > > > this reliable to tell whether or not my speedometer is dead on? I
> > > > have NOT changed the speedometer gear yet, or had the computer changed
> > > > to reflect the larger sized tires. Also, I am not using my OD (6th)
> > > > much on the highway, but when I get up to 65 (the speedometer says
> > > > 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> > > > be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> > > > not sure what speed or what rpms I should be using 6th. Any help is
> > > > really appreciated.
>
> > > The (ones that have posed here) older TJ speedometers became correct
> > > when 31" tire were put on.
>
> > > Your mile per minute is a good base to tell it is close.
>
> > > The only other way is to find a measured mile or a friend with a GPS or
> > > even ask a cop to pace you because 'you just got new tires and don't
> > > want to break the law'. Only a cop's speedometer would be reliable for
> > > this, cars can be off too according to tire size.
>
> > > I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
> > > highway which I get with my 4th gear. (have 33's and 3.31 gears) That
> > > rpm gives me good throttle control and prevents engine lugging. I also
> > > get a pretty stable 11L/100km or 23 mpg running there.
>
> > > If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
> > > which makes for the need of the full gas pedal travel to adjust speed or
> > > hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
> > > my gas mileage by at least 5-8 mpg.
>
> > > You can find out easy. Just compare gas mileages when using only 5th on
> > > the highway and when using 6th mostly. I have one trip I do lots to get
> > > bush camping which is 201 km from gas station to gas station so I have
> > > an easy check point.
>
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> > > Canadian Off Road Trips Photos: Non members can still view!
> > > Jan/06 http :// www .imagestation,com /album/pictures.html?id=2115147590
> > > (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> > > - Show quoted text -
>
> > So, assuming that my speedometer is correct, running approximately
> > 2500 rpms in 5th gear at 65 mph will NOT hurt my engine or cause
> > increased engine wear? If I were to shift into OD (6th), what is the
> > approximate rpms that I should be running so as to not cause lugging
> > or increased engine wear?
>
> > THANKS- Hide quoted text -
>
> > - Show quoted text -
>
> Oh, nevermind. I think I just answered my own question. : D
>
> I am assuming that the approximate 2500 rpms would apply to the OD
> (6th) gear as well to prevent increased engine wear and lugging?- Hide quoted text -
>
> - Show quoted text -
Which would probably be somewhere in the neighborhood of 70-75 mph in
6th at approximately 2500 rpms.
On Sep 17, 11:34 am, Tracie <brain...@upstate.edu> wrote:
> On Sep 17, 11:26 am, Tracie <brain...@upstate.edu> wrote:
>
>
>
>
>
> > On Sep 17, 11:17 am, Mike Romain <roma...@sympatico.ca> wrote:
>
> > > Tracie wrote:
> > > > Hello all. I have a 2006 Wrangler X with 6 speed manual tranny, 3.07
> > > > gearing, and D30 front/35 rear. I recently upgraded my tires from the
> > > > stock 215/75/15 to 31/10.5/15 BFG All Terrain T/A KO. I am looking
> > > > for a reliable way to tell if my speedometer is off at all with the
> > > > tire upgrade. I do not have access to a GPS system. What I HAVE done
> > > > is to use the tripometer (with tenths), and hold steady at 60 mph (my
> > > > speedometer said 60) for one mile while watching my clock. I am
> > > > EXTREMELY close to going 1 mile in 1 minute by using this method. Is
> > > > this reliable to tell whether or not my speedometer is dead on? I
> > > > have NOT changed the speedometer gear yet, or had the computer changed
> > > > to reflect the larger sized tires. Also, I am not using my OD (6th)
> > > > much on the highway, but when I get up to 65 (the speedometer says
> > > > 65), I am running at about 2500 rpms in 5th. Is this bad, or should I
> > > > be shifting into the OD (6th)? I do fine with 1st through 5th. Just
> > > > not sure what speed or what rpms I should be using 6th. Any help is
> > > > really appreciated.
>
> > > The (ones that have posed here) older TJ speedometers became correct
> > > when 31" tire were put on.
>
> > > Your mile per minute is a good base to tell it is close.
>
> > > The only other way is to find a measured mile or a friend with a GPS or
> > > even ask a cop to pace you because 'you just got new tires and don't
> > > want to break the law'. Only a cop's speedometer would be reliable for
> > > this, cars can be off too according to tire size.
>
> > > I find 'my' engine 'much' prefers to be running at 2300-2500 rpm on the
> > > highway which I get with my 4th gear. (have 33's and 3.31 gears) That
> > > rpm gives me good throttle control and prevents engine lugging. I also
> > > get a pretty stable 11L/100km or 23 mpg running there.
>
> > > If I go to overdrive or 5th gear, the rpm drops to 1750 or so at 65 mph
> > > which makes for the need of the full gas pedal travel to adjust speed or
> > > hold a hill or wind vs a twitch of the pedal in 4th. This low rpm drops
> > > my gas mileage by at least 5-8 mpg.
>
> > > You can find out easy. Just compare gas mileages when using only 5th on
> > > the highway and when using 6th mostly. I have one trip I do lots to get
> > > bush camping which is 201 km from gas station to gas station so I have
> > > an easy check point.
>
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> > > Canadian Off Road Trips Photos: Non members can still view!
> > > Jan/06 http :// www .imagestation,com /album/pictures.html?id=2115147590
> > > (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> > > - Show quoted text -
>
> > So, assuming that my speedometer is correct, running approximately
> > 2500 rpms in 5th gear at 65 mph will NOT hurt my engine or cause
> > increased engine wear? If I were to shift into OD (6th), what is the
> > approximate rpms that I should be running so as to not cause lugging
> > or increased engine wear?
>
> > THANKS- Hide quoted text -
>
> > - Show quoted text -
>
> Oh, nevermind. I think I just answered my own question. : D
>
> I am assuming that the approximate 2500 rpms would apply to the OD
> (6th) gear as well to prevent increased engine wear and lugging?- Hide quoted text -
>
> - Show quoted text -
Which would probably be somewhere in the neighborhood of 70-75 mph in
6th at approximately 2500 rpms.
Re: Re: ACCURATE SPEEDOMETER?
On Mon, 17 Sep 2007 08:36:28 -0700, Tracie <brainart@upstate.edu>
wrote:
>Which would probably be somewhere in the neighborhood of 70-75 mph in
>6th at approximately 2500 rpms.
Your speedo is way off.(big tires will do this) In 5th with current
tires, 2500RPM would yeild about 74 MPH and 6th (.82 OD) 2500 would
yeild about 91 MPH based on quoted tires sizes and axle ratios.
Again you can do the math yourself
http :// www .snoman,com /HTML/axlecalc_5a.html
-----------------
TheSnoMan,com
On Mon, 17 Sep 2007 08:36:28 -0700, Tracie <brainart@upstate.edu>
wrote:
>Which would probably be somewhere in the neighborhood of 70-75 mph in
>6th at approximately 2500 rpms.
Your speedo is way off.(big tires will do this) In 5th with current
tires, 2500RPM would yeild about 74 MPH and 6th (.82 OD) 2500 would
yeild about 91 MPH based on quoted tires sizes and axle ratios.
Again you can do the math yourself
http :// www .snoman,com /HTML/axlecalc_5a.html
-----------------
TheSnoMan,com
Re: ACCURATE SPEEDOMETER?
SnoMan wrote:
> On Mon, 17 Sep 2007 08:36:28 -0700, Tracie <brainart@upstate.edu>
> wrote:
>
>> Which would probably be somewhere in the neighborhood of 70-75 mph in
>> 6th at approximately 2500 rpms.
>
>
> Your speedo is way off.(big tires will do this) In 5th with current
> tires, 2500RPM would yeild about 74 MPH and 6th (.82 OD) 2500 would
> yeild about 91 MPH based on quoted tires sizes and axle ratios.
>
> Again you can do the math yourself
>
> http :// www .snoman,com /HTML/axlecalc 5a.html
> -----------------
> TheSnoMan,com
Your site appears to be totally useless garbage.
No one 'knows' their freaking tranny ratio or their t-case ratio, most
do good to have their tire size and gear ratio.
'Comparing' tire sizes of old vs new to get a new speedometer reading is
garbage. The old tires were 'not' certified to have the correct speed
vs the gauge speed, so that is a GIGO situation. Garbage In Garbage Out.
If I punch in my numbers for how fast I should be going at 2300 rpm and
say my T-5 tranny in 4th is 1:1 and my Dana 300 t-case in high is 1:1
and my gears are 3.31 and my tires are 33", the 'calculator' gives me a NaN
If I put in my tire size and gear ratio I get infinity for a 'new' gear
ratio. Gee I thought gear ratios were set by the 'physical' gears, not
by some mythical number.
Care to explain?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http :// www .imagestation,com /album/pictures.html?id!15147590
(More Off Road album links at bottom of the view page)
SnoMan wrote:
> On Mon, 17 Sep 2007 08:36:28 -0700, Tracie <brainart@upstate.edu>
> wrote:
>
>> Which would probably be somewhere in the neighborhood of 70-75 mph in
>> 6th at approximately 2500 rpms.
>
>
> Your speedo is way off.(big tires will do this) In 5th with current
> tires, 2500RPM would yeild about 74 MPH and 6th (.82 OD) 2500 would
> yeild about 91 MPH based on quoted tires sizes and axle ratios.
>
> Again you can do the math yourself
>
> http :// www .snoman,com /HTML/axlecalc 5a.html
> -----------------
> TheSnoMan,com
Your site appears to be totally useless garbage.
No one 'knows' their freaking tranny ratio or their t-case ratio, most
do good to have their tire size and gear ratio.
'Comparing' tire sizes of old vs new to get a new speedometer reading is
garbage. The old tires were 'not' certified to have the correct speed
vs the gauge speed, so that is a GIGO situation. Garbage In Garbage Out.
If I punch in my numbers for how fast I should be going at 2300 rpm and
say my T-5 tranny in 4th is 1:1 and my Dana 300 t-case in high is 1:1
and my gears are 3.31 and my tires are 33", the 'calculator' gives me a NaN
If I put in my tire size and gear ratio I get infinity for a 'new' gear
ratio. Gee I thought gear ratios were set by the 'physical' gears, not
by some mythical number.
Care to explain?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http :// www .imagestation,com /album/pictures.html?id!15147590
(More Off Road album links at bottom of the view page)
