Perfect wheel size/offset for fast road use?
 

I am about to order a set of Compomotive eight spoke alloy wheels for my '00 NB.

This is my fourth MX5 and my third NB, I'm pretty set on 15" diameter wheels and plan to run horizontal wishbone ride height.

The wheels are custom made by Compomotive with the correct centre bore measurement and it also means I can choose pretty much any offset and width I like.

I am considering fronts as 7x15 ET35 with 195/50/15 and rears 8x15 ET? with 205/50/15

Which sizes would you recommend for a primarily fast road orientated car that would be aesthetically pleasing, not cause any arch scrubbing and offer the best performance?

>= 215 or bust.

Why different wheel and tires sizes front to rear?

I'm looking for some useful opinions, Braineak has suggested that I run a minimum of a 215 section tyre and Hustler has posted from his favourites folder.

Do you think a staggered setup is unnecessary?

I would say that yes, it's unnecessary. You could run 15x8's with equal tire sizes at all four corners allowing to properly rotate your tires. You could run a 205 tire on x8's if it's a set of Azeni's which measure up pretty close to a true 215. Otherwise, I'd say 215-245 width tires. If you are determined to run a staggered set up, a 225/45 on the 15x8 and a 205/50 on a 15x7 would work out well.

Cheers chricto, what offsets would you recommend? Are there any clearence issues running a 225 tyre?

Honestly, anything can fit if you really want it to. A conservative offset, say +40 - +20, shouldn't be a problem for the NB. You would have to roll the fenders if you plan on going with lower offset wheel or if you are planning on a really low ride height. Neither of those should concern you if you are truly looking for a performance set up. I'd stay between +35 - +20 offset for performance reasons. Here are some useful calculators to help you find what will work.

http://www.1010tires.com/WheelOffsetCalculator.asp
http://www.1010tires.com/tiresizecalculator.asp
http://949racing.com/6ulfaqsandfitmentinfo.aspx (the top 2 links are what Hustler was referencing with his link.)

Perfect, sorry for wanting to be spoon fed but I need to order these tomorrow and didnt want to fuck it up!

It's worse than that; it's a bad idea because it screws with the handling balance. Pick a size and use it at all four corners, or be prepared to start screwing around with spring rates and various anti-sway bars to restore the balance that's largely inherent to the stock setup.

As for size, I like moderate widths (195 to 205) because I don't track yet track my cars and I've de-powered the power steering racks. For me it's more about balance than looks, and what you actually use the car for rather than what you want others to think you use the car for. I can't see the outside of my car when I'm driving it, but I can sure feel how it goes down the road.

As for offset, I like as close to stock as I can get for the same reasons stated earlier.

225/45? No. 225/50, yes. Problem is street tires are common in the 225/50 size, where as 225/45 are all race rubber.

I ran the 225/50, and rubbed on the fenders and front liners. I removed the front liners, and 30 minutes with a hammer bending in all the tabs made it fine. I was also running a higher than normal ride height. Lower than stock, but not as low as most here (and most here don't "slam" their rides).

Hustler posted that because the wheels 949 racing sells were specifically designed for the miata, and therefore have the perfect offset for you. Look tits too.

Cheers, I did look at the 6UL but simply prefer the look of minilight style wheels.
I bet they're a damn sight lighter than the Compomotives too.

This is relevant to my interests. Assuming "normal" ride height is 12.5 inches, how high were you running?

13? 13.5? Lower than stock, higher than most run. It was KYB shocks with FM springs, and this rubbed slightly in the back, front was ok if I remember correctly. I made .66" spring spacers for all four corners, so I didn't drive around enough to figure out if the front had any major issues. Any little bump was scraping a tad in the back though.

Wheels/tires with stock height:
Attachment 193805
Wheels/tires lowered:
Attachment 193806

Because the 225/50 is bigger than stock, it still fills the fender nicely, the car just doesn't sit as low.

those tires are humongous.

yeah, he made the mistake of compromising "looks" for performance. should have gone with 155s.

On x9 inch wheels

Cereal. I need to post those pictures in the reverse stretch thread.

I think it would look fine on a 9" rim. Still, first pic is 4x4 territory.

I suggest you stick with the same size all around. For me the best wheel + tire size combo for daily driving is 15x7 ET35 with 205/50/15.

If you choose the right (light) wheel and (sticky) tire, it will be a noticeable upgrade from stock in both driving and looks.

225/45/15 is also a great size, but not a lot of options there.

Hope that helps