Slow speedo
#1
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Year: 1992
Model: Comanche
Engine: 4.0
Slow speedo
So other day I drove past one of those cops 'your speed is' things. And I thought i was doing 50 (I made sure I was doing as close to it as possible) And the thing showed up as 45. Now I normally do 5 over all the time. (I know, I know, you should speed blah blah blah..Go spill some coffee on your shirt or something as equally as day ruining) I just thought people were actually starting to do the speed limit even old people but I guess not
Now my question is, what could be causing this? I just got my Jeep from an auto auction and I have no idea about anything the PO did.
Also my tires are kinda small, theyre like 27s on 16 inch stock rims.
Now my question is, what could be causing this? I just got my Jeep from an auto auction and I have no idea about anything the PO did.
Also my tires are kinda small, theyre like 27s on 16 inch stock rims.
#3
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Year: 1997
Model: Cherokee
Engine: 4.0 L
i have never ever been driving a car where the speedo was accurate. it has always been showing between 5 - 10% to much.
i dont know why they make it like that. it should be posible to have it more accurate.
i dont know why they make it like that. it should be posible to have it more accurate.
#4
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Year: 1992
Model: Comanche
Engine: 4.0
Originally Posted by Moncheche
Look at the sticker on your drivers door. It will tell you what size tires and rims came with your XJ.
15" was common, but 16" rims did exist.
My guess is that your tire size is not stock.
But yeah I'm guessing its cause there so small, is there a way to tell if its been regeared for bigger tires?
Edit: it's a 16" rim..it says R16 lol
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Last edited by Zack92MJ; 07-31-2011 at 10:38 AM.
#6
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Year: 1999
Model: Cherokee
Engine: 4.0L
The bigger the size of tire you go the slower your speedo' shows. Rim size won't affect it, its the actual size of your tire. I have 235's and at 60 mph on the speedo' I'm actually running at 63-64ish. And the difference increases the faster youre going.
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#8
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Year: 1999
Model: Cherokee
Engine: 4.0L
Originally Posted by fatboyadams
If you have a 265.70R15 and a 265.70R16 the 16 is one inch bigger take a look at 1010tires.com really good info
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Last edited by SnakeEyes814; 07-30-2011 at 09:16 PM.
#10
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Year: 1994
Model: Cherokee
Engine: 4.0 L/242 CID I-6 High Output MFI
Stock tire size for most XJ Cherokees is 225/75R15. This translates to 28.287" by actual conversion. Each tire manufacturer has slight variances that can be as large as half of an inch (sometimes more) in overall tire diameter. Tire diameter is also affected by the inflation level of the tire and the load on it. All of this can have an effect on your speedo. Right now, I've got 30k miles on my Kelly Safaris, and the speedo registers 65 MPH when I'm doing 64. My snow tires (215/75R15) make my speedo register 5 MPH over my actual speed.
#11
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if the tires are bigger than stock, the speedo will read slower.
if the tires are smaller than stock, the speedo will read faster.
put the right size tires on, and your speedo will be more accurate.
or get a GPS.
if the tires are smaller than stock, the speedo will read faster.
put the right size tires on, and your speedo will be more accurate.
or get a GPS.
#12
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Year: 1999
Model: Cherokee
Engine: 4.0L
Originally Posted by caged
if the tires are bigger than stock, the speedo will read slower.
if the tires are smaller than stock, the speedo will read faster.
put the right size tires on, and your speedo will be more accurate.
or get a GPS.
if the tires are smaller than stock, the speedo will read faster.
put the right size tires on, and your speedo will be more accurate.
or get a GPS.
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#14
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Year: 1999
Model: Cherokee
Engine: 4.0L
Originally Posted by fatboyadams
No kidding! Lol plus size rims can and will affect overall diameter unless you go to a lower profile tire
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