hey guys i currently have the 245/45 on the 18 inch premium wheels and was considering getting 255/45/18 i figure the 10 MM diff would look a bit better and not overkill. does anyone have pics on this setup? my ride is fairly low since installing Sprint springs anyway. some help would be appreciated. PICS PICS, PICS please. thanks RX
BTW anyone know a good and cheap place for tires in the fort lauderdale area? I'm looking to get like KUMOS or Continetalls, any goodlooking cheap tires out there? how about Ventus tires? anyway, some thing cheap cause i will soon be getting some volk 19's thanks again. RX

 

Bailyrx (I think) is running 275's on the rear and no problems. I'm thinking about 265/40/18 and 245/40/18 myself.

 

Right You Are... 255's Front 275's Rear

 

Are those wheels the same dimensions as the stock coupe wheels?

 

yea but im talkin bout the stock 18's.

 

i forget the math, but they're pretty darn close diameter wise.
never had any slip/vcd issues at all... except when i spin them on purpose, of course!
255/45 r17..... 275/40 r17

 

I'm thinking about 265/40/18 on the rears and 245/40/18 up front. Although 275/40/18 and 255/40/18 is a better match. I'm afraid that will be pushing reality...

Any wear problems with the 275 setup?

 

are we all talking about the stock coupe 18's? theres no way youre getting a 275 on that rim and look good. way too much bulging out i would think. IMO 265 would be pushing it. and i assume theres no way that a 275 would not rub, specially with lowering springs. RX

 

I think the OEM sedan wheels are the same width as ours, so the fitmant would be similar.

 

no weird wear issues yet... it's been only 8 months though (sarcasm)
I still need to get an alignment too. The bulge is non-existent... at least compared to other sized tires I've seen, on a variety of rims. I've done VIR full course with these tires, no problems. Also several auto-cross events.
I also have about a 1in drop & 1 in spacers on the rear

 

yea but those look like the 17's, i have 18 inch and dropped almost 2 inches if not that.

 

yea but those look like the 17's, i have 18 inch and dropped almost 2 inches if not that. RX

 

The overall diameter for the rear will be bigger by about .3" (vs. the 245/45-18). I'm not sure if it will make much difference to the VDC or TCS system, but hard to know for sure. I think the TCS system mainly has difficulty with smaller diameter rears, i.e. with reduced front to rear stagger, not with increased stagger.

 

255/45/18s will be fine for the rear. You'll be within the recommended tolerance of 0.3" on overall diameter. To be exact you will be at 27.0" where stock is 26.8" for the rear. (Of course this assumes a tire with about 10/32 of tread. Drag radials or tires with 11/32 will throw this off somewhat.)

You may be able to mount wider tires on your stock rims, but you'll void the tire warranty and probably any other warranty coverage related to your rims and or suspension.

As a guide 8" and 8.5" wide rims are recommended to accept no more than a 255 tire. 9.0" can accept up to 275. 9.5" can accept a 285. (Don't ask me why a tire mfrs don't allow a 265 on a 8.5" rim, because I don't understand either.)

If you want to stay with an 18" rim, then optimally you'll want a 8.5" front and a 9.5" rear rim with 245/40/18 and 275/40/18 tires. I would try to keep your offsets around 25-35 front and 35-45 rear.

If it helps, here are the specs on a stock 18" rim set up:

wheels: 18x8 30mm offset all (4).
tires: 225/45/18f (height 25.8") 245/45/18r (height 26.8")

Have fun!