Speedo Recalibration

[SAMBO456]

I Have Just Borught New Rims Which Are 2 Inches Bigger Than What I Have. How Much Is This Going To Affect My Speedo And How Do I Fix The Inbalance.

Cheers

[bennjamin]

check this out - enter all information you can about your "old" rims and then your "new" rims.

http://www.miata.net/garage/tirecalc.html

[wlee2]

well (lets assume you have 15 inch rims)

2 inches Bigger thats 17 inch..

let say on your stock 15 inch rims you run 195/55/15 thats a Total tire Diameter of 23.44

what u would want to do is get the overall tire diameter with your 17 inch as close to that of the stock ones..

closest one i got is 205/40/17 which is 23.45

this will effect your speedo a little bit

so when your speedo reads 60 kmph with your new tires your going about 60.03 Kmph

for more information u can check out the spreadsheet here
http://www.ozhonda.com/forum/showthread.php?t=35200

[SAMBO456]

Thanks for the help guys

Old tyres - 195/60-15
New tyres - 205/40-17

Using a really good website - http://www.lrc.org.au/4wdstuff/tyre.htm

Speedometer 103.22


Error @ 100 kphDifference -3.12%

Not much difference. Just have to watch the speedo more carefully.

[LouNC]

If you have a friend who owns a GPS unit, you might borrow it and take it along for a ride. Assuming you have a clear view of the sky while traveling on the freeway, you should be able to get a good steady-state speed reading and compare it to the speedo at several points. That way, you'll know what your actual speed is at several "indicated" speed points on the clock.
Lou