Well hopefully once i get the tune figure out it'll be time for some new rear tires.

I have a 10" wide rear rim. Whats the biggest tire i can run?

 

Depends on which brand you go with, from what I've heard michlen pilot super sports run wider then Nittos, I was told that 305 is the widest you can go with thePSS's but 315 is what you can fit with Nitto Invo's. But I may be wrong.

 

From Tirerack 295 is the max width they recommend for a 10" wheel. 305 they recommend a 10.5". I found this older thread which is speaking about this topic.

I would recommend talking to one of your local tire dealers, they should be able to give you good advice.

 

It depends on the tire as well... some 305's will fit, some tires 295 is the max recommended. Easiest way to check - go on Tirerack and look at the specs on whatever tire you're considering. The recommended rim size and max/min wheel widths are listed too.

I just picked up some 10" wide wheels with 275/40/18's mounted. Clear the front with no spacer, but only about 1/4" clearance to a bolt by the strut. Probably would need a spacer (with these particular wheels at least) to go 285+ in the front. Rears have more clearance

 

You can run a 305, but it will stick out.
I am running a 10" wheel in 48 offset with a 295 tire and it sits flush with the panels lip. I wanted to run a 305, but they would have stuck out about 1/2 inch.

 

I am running the Nitto NT05r 305/35 on a 19x10 with 47mm offset. I am really happy with the stance. It seems to fit pretty darn flush with this particular tire. I do agree that depending on what brand you choose, it could easily stick out some. I hope this little bit of info helps. Let me know if you would like any other pics from different view. Thanks. Good luck with everything. Post some pics when you're done.

 

For track days I run an 18x10 SVE drift wheel with 305 series racing slicks.

 

Perfect stance.