Speedometer accuracy w/31" tires - did dealer lie?
10-23-2003, 12:29 PM
#21
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
My Garmin EMap unit is dead on for speed.
I 'think' that 31" tires are right in-between two spedo gears for
accuracy.
MY CJ7 came to me with 31's and my spedo was reading fast of all
things. About 4-5 mph fast.
I went to 33's and my spedo is now dead on.
Same for our Cherokee. It reads dead on with P235's. Stock tire would
have the spedo reading fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
I 'think' that 31" tires are right in-between two spedo gears for
accuracy.
MY CJ7 came to me with 31's and my spedo was reading fast of all
things. About 4-5 mph fast.
I went to 33's and my spedo is now dead on.
Same for our Cherokee. It reads dead on with P235's. Stock tire would
have the spedo reading fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
10-23-2003, 12:29 PM
#22
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
My Garmin EMap unit is dead on for speed.
I 'think' that 31" tires are right in-between two spedo gears for
accuracy.
MY CJ7 came to me with 31's and my spedo was reading fast of all
things. About 4-5 mph fast.
I went to 33's and my spedo is now dead on.
Same for our Cherokee. It reads dead on with P235's. Stock tire would
have the spedo reading fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
I 'think' that 31" tires are right in-between two spedo gears for
accuracy.
MY CJ7 came to me with 31's and my spedo was reading fast of all
things. About 4-5 mph fast.
I went to 33's and my spedo is now dead on.
Same for our Cherokee. It reads dead on with P235's. Stock tire would
have the spedo reading fast.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
10-23-2003, 03:21 PM
#26
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
Hi Patrick,
If you want your wife to be abel to drive by a school yard at full
speed, and know that radar gun isn't go to bit her, than replace the
speedometer drive gear with the correct one listed at:
http://go.jeep-xj.info/HowtoSpeedoGears.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
If you want your wife to be abel to drive by a school yard at full
speed, and know that radar gun isn't go to bit her, than replace the
speedometer drive gear with the correct one listed at:
http://go.jeep-xj.info/HowtoSpeedoGears.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
10-23-2003, 03:21 PM
#27
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
Hi Patrick,
If you want your wife to be abel to drive by a school yard at full
speed, and know that radar gun isn't go to bit her, than replace the
speedometer drive gear with the correct one listed at:
http://go.jeep-xj.info/HowtoSpeedoGears.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
If you want your wife to be abel to drive by a school yard at full
speed, and know that radar gun isn't go to bit her, than replace the
speedometer drive gear with the correct one listed at:
http://go.jeep-xj.info/HowtoSpeedoGears.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
10-23-2003, 03:21 PM
#28
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
Hi Patrick,
If you want your wife to be abel to drive by a school yard at full
speed, and know that radar gun isn't go to bit her, than replace the
speedometer drive gear with the correct one listed at:
http://go.jeep-xj.info/HowtoSpeedoGears.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
If you want your wife to be abel to drive by a school yard at full
speed, and know that radar gun isn't go to bit her, than replace the
speedometer drive gear with the correct one listed at:
http://go.jeep-xj.info/HowtoSpeedoGears.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
Patrick Mills wrote:
>
> Hello,
>
> Got a new '04 Wrangler X in September. I plan to use this jeep for "fun"
> driving on-road in warm weather, occasional snow driving (on-road) and
> mild off-roading (no serious mudding, rocks or hill-climbing). It is not
> a daily driver.
>
> The vehicle is a stock Wrangler X with I6 engine and 3.73 gears. The only
> mod is a set of 31" AT tires (Dayton Timberlines, not BFG) and black
> wheels with faux beadlock-looking attachments - obviously for appearance
> only.
>
> I plan to gradually outfit this jeep with more trail-friendly gear,
> although I don't plan to lift it or use larger tires.
>
> My only question at this time is about speedometer accuracy. When I took
> delivery, they made me wait for about 45 minutes while the salesguy said
> they were making an adjustment so the speedometer would read accurately
> with the (dealer-installed) 31" tires.
>
> I happen to have a GPS, and, according to it, the speedometer reads slow
> by between 4 to 6 mph.
>
> Is a GPS a good way of measuring speedometer accuracy? I'm not sure if
> the dealer just gave me a run-around, did something wrong, or if my GPS is
> just not an accurate device for measuring actual vehicle speed (I use it
> for geocaching, and it's been very accurate for that).
>
> Thanks for any advice or comments. I enjoy reading this group.
>
> PLM
>
> --
> [ ]
> __OIIIIO__
> |||=oo=|||
> ||| |||
10-26-2003, 07:40 AM
#29
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
My '02 TJ speedo with 31's is almost dead-on accurate according to my GPS.
It came with 30" tires from the factory and with those the speedo read a few
MPH fast.
Tom
"Jason Killian" <jkillian@coas.oregonstate.edu> wrote in message
news:Pine.SOL.4.56.0310231031290.7295@cole...
> Yeah, I get the same offset - 31's run about 4mph faster than the speedo
> on my TJ
It came with 30" tires from the factory and with those the speedo read a few
MPH fast.
Tom
"Jason Killian" <jkillian@coas.oregonstate.edu> wrote in message
news:Pine.SOL.4.56.0310231031290.7295@cole...
> Yeah, I get the same offset - 31's run about 4mph faster than the speedo
> on my TJ
10-26-2003, 07:40 AM
#30
Guest
Posts: n/a
Re: Speedometer accuracy w/31" tires - did dealer lie?
My '02 TJ speedo with 31's is almost dead-on accurate according to my GPS.
It came with 30" tires from the factory and with those the speedo read a few
MPH fast.
Tom
"Jason Killian" <jkillian@coas.oregonstate.edu> wrote in message
news:Pine.SOL.4.56.0310231031290.7295@cole...
> Yeah, I get the same offset - 31's run about 4mph faster than the speedo
> on my TJ
It came with 30" tires from the factory and with those the speedo read a few
MPH fast.
Tom
"Jason Killian" <jkillian@coas.oregonstate.edu> wrote in message
news:Pine.SOL.4.56.0310231031290.7295@cole...
> Yeah, I get the same offset - 31's run about 4mph faster than the speedo
> on my TJ
