Im trying to see if see tire sizes are good for these rims. WOuld 285 work for the back.. would i have trouble with the car hitting the fender after i lower the car with the slp shock/spring combo..

18x9.5 Wheel Offset: +46mm 245/40/18 front
18x10 Wheel Offset: +33mm 275/35/18 back

 

what would anyone recommend be the tire sizes for these rims.... and would i be ok with 285 in the back and 3/4 in drop from stock any problems with that...

 

The 18x10 33mm offset wheel puts the tires a shade (0.17") further out from under the fender than the popular 17x11 50mm offset wheels. If the car is lowered and you put a wide tire on the wheel, rolling the fender lip will probably be needed. You'll know as soon as you go over the first bump.

There's guidelines to tire sizes and wheel width in the FAQ. You can run anything from 265 - 295 on an 18x10" wheel.

 

these are the dimensions i got from tirerack

18x9.5
Recommended Tire Size: 245/40-18
Wheel Offset: +46mm
** Lightweight: 24.3 lbs.


18x10.5 Optional Rear
Recommended Tire Size: 275/35-18
Wheel Offset: +33mm
** Lightweight: 25.1 lbs.

I dont know if im going to have a problem with these....

 

You threw in a curve ball by increasing the wheel width to 10.5" with the 33mm offset. The tire is going to be outside the fender. You want a 45mm to 55mm offset for a 10.5" wide wheel.

 

Wouldnt 275 be a better tire width on the 9.5" rim and a 295 be a better width on the 10.5" rim? Seems like 245 and 275 would be on the small end of what you could fit on those wheel sizes

 

You would think tirerack would know that putting such a wide wheel with that kind of offset might have problems... i could them and they said it shouldnt be a problem, that they make conservative sizes... Now I'm thinking should i go with their set up or just go with 18x9.5 all around..

 

There's a lot of questionable info out there on wheel fitments. AFS says the 37.5mm offset 17x11's will fit T/A's but not Z28's. 90% of the people feel that they stick out way to far on both cars. AFS says you can't put 17" wheels on a 4th Gen convertible. That is wrong.

Tire Rack's recommendations for tires are on the "narrow" end of the spectrum - but they aren't "wrong". In both cases, they are quoting you the narrowest possible tire you can correctly fit on the wheel. To many people, tires that narrow look "stretched".

If you think about it, put a very narrow tire on a wheel with too little offset, and its not as likely its going to rub. It comes down in many cases to what "looks good", and that's somewhat subjective.