I have Konig Imagine wheels now with 215/35-18. I'd like to move up to a better tire, but the two I'm interested in are only available in 225/35-18. If my math is right, that's about a 1.4 or 1.2% change in tire circumference (+~1% speedo change). Is this correct, and is this size change okay? The wheels are 18 x 7.5.

Thanks!


EDIT: Alex, I saw your response to a previous question (you said 225 was wide!). This should be the specs on the wheel: 18x7.5 4x100 45mm offset. Is 225 too wide? Should I find a different tire?

 

It is ususally best to stay close to the same. Here is a good site to see the changes.
http://www.1010tires.com/TireSizeCalculator.asp
hope this helps.

 

at 45mm, it might fit.

 

Here is another great link for tire size comparisons.

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

 

I understand the tire should be as close in size to the stock tires as possible (that's pretty obvious). I'm just trying to figure out if they will fit without rubbing (fender, or inside). I'm lowered about 1" on H-sport springs (stock shocks).

Circumference difference is .8 inches, or 1.2% on the speedo.

I'm just not real happy with the selection at 215/35-18. The only Max Performance is the Kumho Ecsta MX which I'm not real interested in, and the only two Ultra Performance are the KDW 2 and Parada Spec-2. Moving to 225/35-18 has both of these, but opens up the Pole Position S-03 (my favorite tire), Eagle F1 DS-G3, and Pilot Sport PS-2. More expensive, but much better tires IMHO.

 

Any luck on this decision? I was thinking about the same thing, but it sounds like you are further along than me.