Hey guys,

Been looking at a used set of Toyo Open Country A/T's which are 31x10.5R15 on aluminum rims 5 on 5.5 bolt pattern... I know the rims will fit, just curious what you guys think about running a 15" tire versus the 16"... I have 285/75/16's on it now and am looking to get some gas mileage back, and well less strain on the driveline seems like a good reason too lol...

Think they will look to small?

 

The 31's are equivalent to 265/75/16's, which is a stock size tire. Your 285's are equal to a 33" tire. As long as the 15's will fit, go for it, there won't be a noticeable difference between them and 16's.

 

I dont see it being a problem at all, I dont think you should notice the difference at all either using 15's as opposed to 16's either. I say go for it, only problem might be wheel wells looking less full, but thats cosmetic.

 

This is what the difference in size actually is:

Specification Sidewall Radius Diameter Circumference Revs/km Difference
285/75-16 8.4in 16.4in 32.8in 103.1in 614 0.0%
31/10-5 0.1in 2.6in 5.2in 16.5in 3846 -84.0%
265/75-16 7.8in 15.8in 31.6in 99.4in 637 -3.6%

Just pretend there is a line going straight down in each row. Sorry, couldn't get it to transfer properly. This is a tire selection chart. May be it will help? http://www.miata.net/garage/tirecalc.html

 

Thanks guys for the comments and info much appreciated... Going to this size tire will really increase mpg? and less wear on the drivetrain?

 

Yep. Smaller diameter, lighter tire. Less rolling resistance. Probably pick up a point or so on gas mileage.

 

if he keeps his foot out of it. LOLz :P

 

LOL I try my best!... really not as concerned about the gas mileage as much as lessening the strain on the drive train....

 

Properly maintained, won't make that much of a difference on parts longevity.

 

You'll be able to flex better with that 3" lift you've got too.