91ToyTrck

I added the 32x11.50 tires to my truck and well opps I got myself a ticket. I haven't been to a car place yet to have it calibrated. I'm just wondering how much it might be off so I don't do anymore speeding around town. I got pulled doing 77 in a 65 and I had it set on 70. I just didn't think that it would be off that much only going up to 32s, but then again my truck does say it came with 225s stock.

Any thaughts on how much it might actually be off ?

YotaFun

That sucks.

Stepdad got pulled over for the same problem in his blazer back in the day, but he got off scott free somehow...

If you had it set at 70 and you were supposidly doing 77 the I would say it sound like it is about a 7MPH diffrence. It would be safe and go with that at least as a start.

rockota

Simple math... What is the circumference of the stock tires? What is the circumference of the 32's? Difference in percentage is?

04 Rocko Taco

yeah it won't be a flat speed, it will be a percentage 33's from stock yeild about a 10% difference in odo/speedo. What size tires did you have stock, and what size are they now....check out this link, it does the calculations for you. http://4wheeldrive.about.com/gi/dyna...ech_calcs.html
Speedo Check is the last one. Good luck.

mastacox

Sounds like your speedo is about 10% off.

4mydogs

Got GPS? That'll show you how far off you are at any speed.

wjwerdna

http://www.discounttire.com/dtcs/infoTireMath.dos has a great calculator

wjwerdna

and use "292-70-16" in the calculator to get a 32x11.5x16 or "292-74-15" to get 32x11.5x15

Saint_Berzerker

Another good calc!

http://www.1010tires.com/TireSizeCalculator.asp

Bill

good rule of thumb is 3% for every inch of size increase. 31-> 32, 3% off, 31 -> 33, 6% off

BuujinBejiita

My 4Runner from 31s to 32s isnt really even off, maybe 3mph but my 88 toyota truck at 60mph was really going 68 so it does vary, Like the above said a GPS will tell you how much your off. My truck got me out of 3 speeding tickets though ''I just put on my bigger tires so I havent re-geared it yet, How fast was I going cause my speedomete said 30'' lol.

jon_7248

Hmmm not sure on what gears he has, but I went from 31s to 33s on my tacoma and got a 10%diff. I went from 31s to 33s on my 4runner (both 5spd btw) and had a 5% diff abouts.

AH64ID

225 is roughly a 28" tire, so 5" difference 5/28 = about 17% off. GPS is the best way, the next best way is to use the mile post signs, or have a friend pace you. The easiset way for a friend to pace you is to have them go 50. See what you read, double the difference. Thats your % off.

As far as I know you cannot have it reacalibrated. If its electronic you can add a calibration module. Dakota Digital sells one.

If its mechanical you can have a calibration gear set added to the cable. Iss Pro of Portland will do this.