So I bought the car with blaque diamond wheels and the tire are a non-name brand. Well one of the tires has a crack in the sidewall already so they whole set needs to be replaced, after a few donuts of course.

Looks like the rims are 20×8.5 – 20×10. I know for the fronts I will need 235/???/20 and the rears I need 275/???/20. I plan on ordering from tire rack. Also open to tire suggestions

 

I'd go with 275/35/20 in the back. Not a crazy stretch but still has some meat on there.

 

What about the fronts? 30?

 

Depending on your wheel offsets you can run a few combos on the 8.5/10" sizes
235/35/20 Front 275/30/20 Rear OR 245/35/20 Front 285/30/20 rear
Both those sets will be very close to your OEM diameter.
My Sedan I run the 2nd combo and also have 8.5/10" rims.
If budget isn't a concern the Michelin Pilot Super Sports are pretty much the gold standard for a summer tire that still has decent wear. Toyo T1 Sports are a good option on a tighter budget, I have Nitto N555s and they have performed well thus far, only have a couple thousand miles thus far though.

 

Only tires I am finding on tire rack with the sizes of 245/35/20 Front 285/30/20 are Hankook v12 evo 2, pirelli p zero, sumitomo HTR Z III, bridgestone POTENZA RE760 SPORT, and Yokahama S. Drive. I have no experience with any of the tires. I have ran Yokagama's in the past and liked them. Wasn't overly impressed, but I liked them. Any other sites I should be hunting?

 

www.treadepot.com ask for Andrew, he takes care of myG37.com guys pretty well.

And do you know your wheel offsets? That will determine what tire size combo will work best. If your offsets aren't positive enough you may have to go down to the 275 set. FWIW my specs are 8.5 +40 and 10 +45, and I've run a 295 in back and still cleared OK.

 

I do not know the off sets... I just got off the phone with Blaque Diamond, the wheel brand, and he would not tell me the off set of his wheels. "I cannot tell you that at this time." Really you make and sell wheels and you cannot tell a customer what the off sets are... He did tell me they are marked on the inside of the wheels, I assume the barrel. Hopefully I don't have to dismount a tire to find out.

BTW Blnewt, I am watching The Opera right now lmao. "You still afraid of clowns?"

 

Have you already ordered these wheels or found a used set that still has tires on them? The offset should be on the inside of the wheel spokes, it shouldn't be in the mount area that would be covered by the tire, but I suppose it's possible If you ordered wheels from them they should state the offsets as it's a vital piece of information.
Since yours is a coupe you have more room to work with so if the offset is in the +30s you should still be ok.
I wouldn't commit to ordering tires until you either find the offsets or if you can't confirm that I would do a test fit of the wheels to see how much room you'll have.
G/L

 

These are the wheels that came on the car when I bought it. I had to buy a spline lug nut key,and I threw my back out again. I think I'm gonna run to the dealer and have them get my the exact offset for the front and rears. I googled the info and it looks like the offsets are 20x8.5 with an offset of 35 and the rears are 20x10 with an offset of 38. I can confirm sometime tomorrow hopefully. I know the guy had to buy spacers to get the wheels to clear the akebonos.

 

Finally got pics of the wheels. Not sure how to read all of this. Oh and I have 15mm spacers on the front wheel and no spacers on the rear.

fronts:







Rears:

 

You've got 8.5 +35 & 10" +38 (It's the ET number).
Should be good offsets for the 245/35/20 & 285/30/20 tire sizes for your coupe.

 

Awesome thanks blnewt! I'll hop on tire rack and the site you recommended and see what I find!

 

Damn there really isn't too much of a choice with these size rims. Looks like I'll be getting the Toyo Proxy T1 sports. A set for just over $733.

 

You should really like that setup, BTW, be sure to ask for Andrew for possibly an even better price