Wheels/Tires: Effect of FE
 

This could be a massive noob question but I am looking at new tires in the next year and am wondering if I am going to be hurting my FE by up sizing the tires.

Current:

195/65/15

Prospective new tires:

205/55/16

Is it that going to make a major difference in my FE? Otherwise I will just upgrade the existing tires with the stock rim.

Thanks.

Curt

hmm... huh.. depends really on the circumference of the new tire. But otherwise, yes it will effect your FE because it's wider, which equals more aero drag, and more rolling resistance.

Check out http://www.miata.net/garage/tirecalc.html
Would give Worse Fuel economy.
More Revs Per Mile
More Footprint (Rolling resistance

That's a great tool. Thanks.

Here is another link>>> http://forum.ecomodder.com/showthrea...&highlight=185

Am I correct to to assume you want a lower number of revs per mile for better FE???

205/55/16 should have the edge on the rolling resistance coefficient, but not by more than 0.001 (everything else but size being equal).
195/65/15 wins on the aero front due to it's reduced frontal area.

I'd go with 205/55/16 if you drive mostly city, 195/65/15 for highway.

Thanks, I decided not to buy larger wheels, so I am now looking at 205/60/15 (stock) and 195/65/15 which is what I have on right now.