CorrdoBrit

The NB 993 is getting new wheels and I'm replacing the Cup II's with 18x8.5 front and 18x10 rear. The car is lowered on MO33 suspension.
The front rims have new Bridgestone RE760 Sport 225/40/18 tires. Seems I have two size options for the rear, either 265/35/18 or 295/30/18. The latter size is not offered in the RE760, rather the S-02. Closest option for the RE760 is 295/35/18 but I'm wondering if there might be rubbing issues with the larger profile as well as slight mismatch with front tires.
What would be the best option?

_snowbird_

Isn't 265 the standard width for a NB rear? Should fit fine on a 10" wheel.

Not sure why you'd go to 295 in your application?

nile13

265. 295 would introduce more understeer with front 225s. Than again, I have no idea what the rest of your setup is like, so this is more of a rule of thumb.

Oh, and I would not put 295s on 10s either way. Depending on a tire, that's about 2" wider mounting section than the rim width. Not a huge deal, but not ideal for the sidewalls. I'd reserve a 295 tire for an 11-12" rim.

CorrdoBrit

Thanks. Exactly what I needed to know. 265 it is then.

e9stibi

275 / 35 / 18 might be another option.

NYC993

285 is OEM on C4S/turbo on 10 inch rim and is a good fit. Make sure offset works. 265 is safer bet, but might be a bit stretched on 10 inch rim, which is not a bad thing. Different tries have different withds even if both are 295/285/265 or whatever. You can look at specs on tirerack.
For track, I run 275 on 11 inch rim and 225 on 9 inch rim. It really stiffens the sidewalls and reduces tire roll.

Cheekybird

These fit great on my C2 993...

18x8 Front: 235/40 (Dim. 25.4)
18x10 Rear: 275/35 (Dim 25.6)

rrc715

I'm running 285/30-18 in the rear. My wheels are 18/10s 95 C2

Cemoto

Same here, no issues.

SleepRM3

Deleted

JPS

Also depends on ride height and offset. 265 on 10et65 lowered to RS +10 worked. 275 on same wheels rub over big bumps sometimes. Fenders rolled just slightly.

ryano

I found 265 to be too skinny and 285 to be slightly too wide. I run 275 and Ideally if they made a 280 it would be perfect IMO. I am a touch over RS+10 and Zero rubbing

JPS

To the OP...remember these cars are hand built and a mm in one direction or the other can be the difference of rub or not. Sounds like Ryano and I are similar in setup, but that "touch over" on his might be not rubbing on the 275. But someone else could maybe squeeze in more.

CorrdoBrit

Looked at the various profiles and heights for the different tire options on a tire calculator site. Albert (Aribop) has the same Enkei RC5 rims (60mm offset) I have and runs 285/30 R18 on a PSS9 lowered C2 without rubbing issues. This seems the best option for my situation.

nile13

Despite whats marked on the sidewall and what calculator tells you, every tire model will have different width and tire height. So, when considering rubbing, only the same offset wheel and the same tire model ran by someone else can be considered. As in JPS' note above, ride height and camber would also matter.