JK speedometer error?
08-23-2016, 08:09 AM
#1
JK Newbie
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Join Date: Oct 2015
Location: Columbus NE
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JK speedometer error?
I swapped the OEM tires on my 2015 JK RUBICON HARD ROCK for OEM GOODYEAR WRANGLERS (same size) from another JK as I wanted a less aggressive thread. My speedometer now reads 3mph faster than my actual speed on my GPS. Is there a way to remedy this problem when switching tires? I did not check it before switching tires, so don't know if it was off from the factory.
08-23-2016, 08:30 AM
#2
JK Junkie
The only way to change it in the computer is with a programmer. I know my '14 came with 32" tires but when I checked the setting from the factory it was set to 31. You can't really go by the advertised size as they vary tremendously. You can use math to calculate what the setting should be by making a vertical mark on the side of the tire at the ground and a corresponding mark on the ground. Roll the Jeep one full tire revolution and make a second mark on the ground at the mark you put on the side wall. The distance between the two lines on the ground is your tire circumference. Divide that by pi (3.1416) to get the diameter.
08-23-2016, 08:41 AM
#3
Super Moderator
That's within reasonable error, not all vehicles are spot on, even out of the factory.
08-23-2016, 09:34 AM
#5
JK Junkie
I agree with this. I had a Mini Cooper that was about 3mph off with stock tires. Dealer said that was within tolerance and they would not consider it a problem unless it was off by at least 5mph.