Widest Tire on stock 18s?

[Lilbear]

Will a 245/55/18 tire fit on the stock 18s? I think it will only throw the speedo off by .04 mph. I think this car should have wider tires to go with all that torque. Thanks in advance.

[Michael]

Using this calculator it should fit. The only question seems to be how much would it crest at high speed on the stock rim ?I know someone here must have tried it ?.
http://www.net-comber.com/tirecalc.html

[jjs]

Originally Posted by Michael

Using this calculator it should fit. The only question seems to be how much would it crest at high speed on the stock rim ?I know someone here must have tried it ?.
http://www.net-comber.com/tirecalc.html

Crest? Do you mean distort? You would have to be at VERY high speeds for modern radials to do that, especially this size which would not distort any more than stock since the width increase is so small.

Are you referring to something I am not getting?

[thematrixhasu]

what if they made a 265/50/18 it would be perfect and i would keep everything stock if any one sees any 265/50/18 please tell me.

[E55 KEV]

Originally Posted by thematrixhasu

what if they made a 265/50/18 it would be perfect and i would keep everything stock if any one sees any 265/50/18 please tell me.

Don't think a 265 width will fit on a 7.5" width rim. 255 may be max.

[jjs]

Originally Posted by E55 KEV

Don't think a 265 width will fit on a 7.5" width rim. 255 may be max.

Very likely not...especially with that short a sidewall...that and I would not like the stresses put on a tire's sidewall that would be more in the 60 range and that wide.

255 sounds about the max, depending on height...if/when I change the tires on this car (WHEN I GET IT BUILT), I would lean toward 245's as my preference.

[E55 KEV]

Yeah, I am waiting for the tire makers to build 245/45/20 (coming on the SRT-8 front) and would get 245/55/18 if remaining with the stock rims.

[II kings 9:20]

Well guys, ideally for cornering, sidewall flex regardless of profile you want to maintain a high rim width to tire ratio (.85 or better no definite rules) used in racing and street. e.g. stock 225 is 8.858". a 7.5" wheel/8.858=0.84 in other words 84%, not bad. A 255 on stock wheels gives a ratio of only 74% kind of like running in a shoe that is too big with your foot flopping around. Imagine a 225 on an 8" wheel, 90.3%, outstanding, quick crisp reflexes. The new Mustang has a ratio of 86% and Acura TSX 82% for comparison.

[Northern Rider]

Originally Posted by II kings 9:20

Well guys, ideally for cornering, sidewall flex regardless of profile you want to maintain a high rim width to tire ratio (.85 or better no definite rules) used in racing and street. e.g. stock 225 is 8.858". a 7.5" wheel/8.858=0.84 in other words 84%, not bad. A 255 on stock wheels gives a ratio of only 74% kind of like running in a shoe that is too big with your foot flopping around. Imagine a 225 on an 8" wheel, 90.3%, outstanding, quick crisp reflexes. The new Mustang has a ratio of 86% and Acura TSX 82% for comparison.

I agree. The stock ratios are correct for cornering, braking and acceleration. The Conti self seal is not my tire of choice, though. I will be going to a better tire come spring.

[II kings 9:20]

Got my Autoweek today, the new MB CLS500 is stunning. It wears 245/40-18 on 8.5 inch wheels an excellent ratio of 88%.