I'm getting closer to buying new tires for my E. I'm really considering going up to a 225 or 235/70-16. I realize the larger tires will lower RPMs which I would like. Since I live in a mountainous area, I'm concerned the heavier tires will bog it down on the hills. Has anyone noticed this? Any other pros/cons to the larger tires?

The diameter change is only 2 and 4%.
paulj

I would suggest staying with no larger than a 28.5" tire to preserve performance and not mess up your speedo/odometer. This site will be a big help.

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

My wifes E has the 225's on it. They are the Nokian WR SUVs. I have timed it in the measured mile. With the E set at 60 Mph it takes 1 min. to complete the run. I don't see the a huge difference in the power. In fact I think it fixed the Spedo Error.

Dom

You might want to look into 235-65-16s...More tire manufactures are making that size now days...The Michelin Energy LX4s suit my E just fine and I haven't noticed a drop in fuel economy, loss of power, etc.. Did I mention that they stick real good around turns?

I have 235/70/16 and I can't tell a difference between those and my 255/35/20 when driving power wise. Then again, both aren't stock. My E never ran with stock tires.

Thanks for the replies. I've had my 225/70-16 Cooper Discover H/Ts for about a week now. So far they seem like great tires. Road noise seems to be down from my old tires. They also seem to stick better in turns, or maybe I'm just pushing it a little harder testing them out.