Tire sizes to keep speedo accurate?

[mwh986]

Found a great deal on some chrome 15" rims, but am peplexed aout the best tire size.

The rims are 15 x 8, so a wider tire should fit well, just don't know the "profile" % measurement to keep the the speedo acurate.

I'm thinking about a 265/60 15. In measuring the OEM VW tire it is 25" in diameter, so I need to keep the new one the same.......................correct?

What are others running out there?

[BrianB]

Why are you worried about the speedo? Just put the best looking tires that meet the look you want and then measure your accuracy later. 9 times out of ten you'll just be doing the same speed as everyone else anyway.

[mwh986]

Thanks Brian,

Just makes sense to me to match the tire with the speedo while I have the option.

Easier now than later, then it becomes a significant $$ issue. Besides the look is negotable to some degree.

What size tires are you running?

[KIM-P]

Give your favorite tire shop a call they can give you all the sizes that are 15"ID x 25"OD. Thats what I did.

[mwh986]

That's too easy..............

[Bill K]

There's a shop in Houston that can put an in-line calibration device that will correct your speedo for the different tire size. They did mine and it turned out amazingly close. Cost was a bit under a $100 if I recall.

[jspbtown]

Go to www.Tirerack.com

They have the specs for every tire they sell.

Your saying a 265/60/15....on the front? The front is the only tire that matters when using a stock speedo. The rears are irrelevant.

[Don]

Tire size calculator including how much your speedo will be off:

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

[BrianB]

Thats right! I cant believe I did not catch that as well. The speedo runs off the front driver wheel.

Your saying a 265/60/15....on the front? The front is the only tire that matters when using a stock speedo. The rears are irrelevant.

[Jack Duncan]

My front tire is 185x60x14. It's diameter is 25", although I run an electric speedometer which is adjustable. My rear tire is 295x50x15. Speedo is perfect after adjustment. The cable turns a pulse generator sending a signal to the instrument. It's made by VDO.