Against everyones good advice, I upsized my tires

Against very good advice I went up one tire size for my 1998 GMC Z71. I went to a 285/75/16. I have had to buy new rims to accomodate the slightly wider tire and have a different offset in the front for proper tire clearence. My concern is that the speedo and stuff like that will be slightly out of wack and I was hoping someone here could tell me waht gears or such I would have to change to run these new tires and get the correct reading on the speedo.

Thanks in advance,

Blair

Reply to
Blair Chesterton
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Correcting the error would get mathematically involved - and I doubt you could find a set of standard gears for an exact correction of it anyway. Know what we used to do in the old days ? Have a friend drive in front of you at a set speed, and check what the error on the speedometer is - then you will know ! Then you simply correct for the error when driving. In your case, the speedo will actually read a bit slower than you are actually going, since the tires will make less revolutions per mile....

Reply to
Zombie Wolf

same idea- brought into the 21st century, and thereby avoiding the inherent inaccuracy in your friend's speedo:

use a handheld GPS to find your TRUE speed-- and proceed as above-- correct as you drive!

Reply to
burntkat

Reply to
mac davis

Yup, Just borrow a Garmin GPS and get your true speeds at 25,

35, 45, 55, 65, & 75 MPH speedometer readings.
Reply to
Dennis Mayer

Reply to
SnoMan

Try this site.It will give you the percentage the different size tires will be on your speed???

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Doug

Reply to
Doug

Thanks to everyone for the advice, it is greatly appreciated.

Blair

Reply to
Blair Chesterton

"" wrote: > Thanks to everyone for the advice, it is greatly appreciated. > > Blair

No way does he have to "RE-Gear" the rear end if he only went up one size.Not even 2 sizes. No braking improvements needed,either;but better pads/braided hoses are always nice.

All you really need to do is >Go to a Speedometer Calibration Shop

Reply to
guitronics

umm-- Duh?

Of course I was addressing the accuracy of his speedo, only.

Reply to
burntkat

bigger

regear

I was referring to SnoMan?s reply,not Burntcat?s......

Reply to
guitronics

Or leave it and consider it an extended warranty :)

--- Rich

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Reply to
Rich Lockyer

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