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I have 33" tires which are about 8% larger than OEM. My speedo registers about 6 mph slower than actual speed - so 65 mph = about 71-72 (according to the radar dispays).

So does my '99's computer read actual speed from a cable in the TC or wheel speed sensors or what? And if the speedo is 8% less than actual does that mead the OH trip computer is reading 8% less than true mpgs?

Thanks, Mike.
 

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The dealer can reprogram for taller tires through the abs module or you can buy a programmer that includes the feature such as a Smarty.

Bob
 

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yes it does but to calculate just add 1 mile to every 10 and you should be good
 
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