Besides lower cost tires and wheels, is there any advantage to running 15" wheels over 16" or 17" wheels? I know 15" alloy wheels will weigh less than a larger wheel but the tires will weigh more so it's probably close to a wash. It seems like larger wheels would yield more stability on the street (possibly at the expense of ride quality).

Thanks!

 

You get more flex in the sidewall.

Way more options on tire sizes and brands in 15's

 

It seems like the weight advantage for 15" tires and wheels really depends on which tire and wheel you actually use. Taking the MB72 wheel as a baseline, the BFG MT KM2 is a whopping 12 pounds lighter in 15" versus 17". However, the Goodyear Wrangler MT/R ends up being only 2 pounds lighter. The Goodyear DuraTrac in 17" is only 4 pounds heavier than the BFG MT KM2 in 15".

I'm really wondering how the JK rides on 15" wheels and 35" tires? I imagine the ride is more compliant but I also expect there is a great deal less lateral stability.

 

I just put on 15'' Soft 8's with 33'' Duratracs and I can hardly tell a difference in power (3.73 auto). It's a "bit" more sluggish, but it was definatly worth the savings on wheels and tires over alloys, especially if 16 or 17''.

 

Is there any issue fitting 15's over the calipers? Does this through the speedo off? and if so, how much? Thanks guys!

 

The MB72 from Discount Tire and Discount Tire Direct in 15" will fit over the calipers. If you change the circumference of your tires it'll throw the speedometer off regardless of wheel size.

I would have to think that if you're at all in tune with the chassis motion of your JK you're going to notice the difference between a 35x12.50R15 and a 35x12.50R17. The wheel is always going to be stiffer than the sidewall of the tire.

 

I think you are making more out of it than there really is.

My jeep went from the stock 255/70R-17 Goodyear SRA tires to a 33/12.50R-15 Goodyear Duratrac
and the tire sidewall flexibiliy difference on my jeep is a non issue on the street. When I air down off road, there is a tremendous benefit, just like I had hoped for.

As always ymmv, but I think you should just go with what looks right for your own vision.