Help me decide what tire size to get

[beta]

I'm placing an order today, so I'd appreciate your input. I'm getting some PSS tires and KW V3 coilovers installed on stock wheels.

Should I stay stock: 225/45R18, 255/40-18. Or should I go wider: 245/40R18 275/35R18 ?

Mostly street use with occasional track.

[onelove]

I run 245/40/18 and 275/3518 on the track, and the same widths in 19 on the street. Wider is better

[beta]

Thanks onelove. Will I need spacers?

Anyone else? Going to put in my order by 4pm so all feedback is appreciated.

[johanness]

Wider ist gut

[Finnegan]

Wider is better on the track, but for combined use on the street a middle ground isn't bad either, say 235/40 and 265/35. With the stock wheel width you're not going to realize all that extra width anyway, and there's something to be said for not going max wide on the rubber when running in the rain. Dry traction is maximized with more rubber, but in the rain it's counterproductive.

The other factor is how the tire is constructed--my 235/40 265/35 Star Specs run "wide" compared to some other tires--you have to check the section width on the measured rim width to get a sense of that. If you want to be more precise, you can adjust up/down in terms of section width based on your rim width vs. the standard measured size. Tire Rack provides these specs for their tires so it's not too hard to get a sense of this (or get a more precise measurement if that's your thing).

It looks like there's a 3/10" section width diff 235/245, and 2/10" inch 265/275 with the PSS. But stock rim sizes are 1/2" smaller than the measured rim size, so that cuts ~2/10" off whatever the section width measurement is (that means you won't see the actual width if you had measured size rims i.e. 8.5" and 9.5").

IIRC those with coils with the wider of the two tires have some minor rubbing issues that can be addressed through fender rolling and having enough front negative camber. On the track I think there was a bit more rubbing when the suspension is under compression--but I think those guys were running wider rims and realizing the full tire width and possibly even a bit of stretch. Does that mean you won't see any rubbing with the wider sizes? I can't tell you that with any certainty--it depends how far you're lowered, camber settings, and the whole section width stock rim thing comes into play. Sorry I cannot be more definitive after all this blabbing on the wider size, but I am pretty confident that the 235/265 size won't give you any problems.

[007MCoupe]

I'm on 245/45 18 - 275/40 18 Hankook V12 right now since I've only seen the track once. I went with a higher profile for that reason...i think finn's argument for 235/265 would do just as well, i just like the beefy look of the 275s. lol

[BTM]

running 235/40 265/35 RE-11s both street and auto x...maybe try a 245 up front next time, car understeers out of the box so maximize your front grip. Feel free to question me about my V3 settings as well if you're looking for any input

[onelove]

Originally Posted by beta

Thanks onelove. Will I need spacers?

Anyone else? Going to put in my order by 4pm so all feedback is appreciated.

I did in the front, but I also roll around with 4 degrees of camber. You may have some fender liner rubbing as well, but it will clearance itself rather quickly.

[beta]

Thanks everyone, went ahead and placed my order. Finnegan thanks for your thoughts on water, hadn't thought of that tradeoff with wider tires. I think I'll stick with it since I'm already super careful in the rain.

As for the understeer, I'm hoping to add a bit of negative camber up front to help with that and so they wear evenly. Still not sure if I want camber plates while I'm at it, or if the -1 ~-1.4 i'll get with the pins pulled out will be enough.

BTM, I'd love to hear about your settings with the V3s, as well as anyone that has input.