Soledad

I hate to have to post about this but I've been doing a lot of searching here and else where and I can't find a picture that shows what I need really well.

I have a 2008 IS350 with the OEM 18" staggered setup (18x8F / 18x8.5R) on stock sport suspension. I won't be lowering the car.

I'm looking into buying the Sport Edition SE-14's and it's the only wheel I'm interested in. They only come in the 18x8.0" with 45mm offset although they may have 35mm as well but I haven't called and asked yet.

I want to run the standard staggered tires 225/40R18 Front - 255/40R18 Rear like I have now but on a wheels in a square setup (18x8F 18x8R). But I'm worried about how far that rear tire is going to extend over the lip of the wheel. Too much tire overhang and that rear end is going to potentially get squishy in the corners.

So essentially I want to run:

Front: 18x8 +35mm 225/40R18
Rear: 18x8 +35mm 255/40R18

Is anyone running a 255/40R18 tire on an 18x8.0" wheel and have pics of it? Did you notice any changes in cornering stability?

Thanks!
Shawn

evopat

I do not have any issue with 255s on my IS350 in the back.

Soledad

Thanks evopat. I don't suppose you could take a couple of pics and post them here?

Does the tire bulge over the wheel lip a lot or seem to look fat on the wheel?

evopat

Hope this helps

Soledad

Thanks!!! That is perfect and exactly what I needed to see.

The tire doesn't really bulge over the wheel lip at all other than maybe a few mm's which
is totally fine.

Now to choose either 35mm or 45mm offset.

flektone

iTrader: (1)

You messaged me about the wheels. Go with 35mm to bring the wheels out as close to the fender as possible. They still wont be anywhere near flush but will look better then 45. I ran 225/45/18 all around. What benefit would you get from running 255 in the rear if the actual wheel isnt wider then the front?

evopat

Soledad. I am sorry I just reread your post. My pic is of an 8.5 wide rear wheel.
Given that the tires for this car have wheel protectors in the design you will not see bulging on a half inch wheel width change

Soledad

evopat: Ah! Ok, no problem and thanks for the update. To be honest I like just a little tire over the wheel lip for protection purposes. The tires on the car now, both front and back, have no wheel protectors so those wheel lips stick out like a sore thumb just waiting to have a chunk taken out of them by a mean curb.

flektone: Thank you for the clarification on the offset. I was worried about the 35mm pushing them out beyond the fender. As for why run a 255/40R18, it's actually my stock tire size with this OEM staggered setup. My speedo is 100% accurate currently according to my GPS units and so the 225 would knock it off just a hair. BUT....the real reason I want to stay with a 255 is because I just love the wide tires in the rear on this car.

Mike_1GO

iTrader: (2)

245 40 is perfect on an 8.5. 255 40 is a bit too large imo. For an 8.0, I would definitely avoid a 255. Too much sidewall flex. I have 235/40s wrapped around 8.5s up front and they look and feel perfect.

Soledad

Thanks Mike. That's what I'm worried about, too much sidewall flex. The car could have a very unbalanced feeling when cornering. I'm not tracking this thing so I may never have to worry about how the rear is going to feel but a quick lane change or a fast on/off ramp could end up being "interesting" although I doubt dangerous.

I guess I could live with it IF it looked good. But finding a pic of a 255/40R18 tire on an 8-inch wheel on a Lexus IS is harder than I thought it would be. Heck, it may not even exist.

I will say that I also like the look of the 19" Genesis Coupe Track wheels on these IS's. But, I'm afraid the tire roar and road noise from a lower profile tire would be far more than what I find tolerable. The roads around here are in really good shape so I'm not worried about damage. But for a Lexus this car sure is noisy in the cabin and I wouldn't want to add more to it.

Mike_1GO

iTrader: (2)

Not a problem! The sidewall will have a bubble look to it. Youll lose a lot in terms of steering feel and not to mention 255s are a few lbs heavier. Only benefit I see is a slightly more comfortable ride. Even then the tire will definitely rub on full lock. Go with a 235 40 on an 8.0. That's your best bet seeing that you want added rim protection and a more compliant ride.