I am getting some wheels and they are 18 by 7.5s and i have been looking at tire choices and want to know what size looks the best if i want to keep the lowest profile possible.

215/40/18

-or-

225/40/18

 

i say 225/40/18

 

so whats the difference in the two sizes???

 

225 is gonna be a lil bit wider than 215

225= width
40= side wall(ex low profile)
18 = the size rim it fits

i think the width and side wall is measured in MM but im not sure

 

Well I have 225's on my 8" wide wheels and they are pretty much stretched, so I say 225.

 

ok thanks. if anyone else could give me some pointers, all is welcome

 

Width is MM, sidewall is percentage of the width. So if you go wider, you will need a smaller sidewall percentage to keep the overall diameter the same.

 

Here man- http://www.1010tires.com/TireSizeCal...bmit&reset=yes
Read and you will see the differance. I would say 225/45/18. 225/40/18 would be a little small, 225/45/18 would be closer to the stock size. You want to be with in +/- 3% of the stock size. Closer is better. 235/40/18 is closest but some can run them w/o rubing and some cant. If you plan on lowering your ride or if its already lowered 225/45/18 would fit just fine and give you a little more rubber on the road.

 

ok i have made my decision to go with the 225/40/18. thanks for the help.

 

wow this thread fails..never thought i would see people worry about what there tire looks like...how about worrying how it performs?

 

im sure they will perform about the same... unless you want to talk about the drag radials i want to throw on some 17s.

 

Get a 235/40 minimum, I ran them on stock rims (18x7) and they barely were wider, 225/40's aren't wide enough for a 7.5" rim.

 

Thanks!

 

But on 235/40 18's and being lowered it wont happen. You will rub. Most on here I have seen and read about rub at stock height from one drgree to an other. If you drive your car agressive on a hard turning road you will rub. Wether is strut or fender rub. Why run the risk, Up to you. But 225 45 18's is as far as I would go. Also consider the more mass you put on the wheel the more stress you put on that wheel and breaking system. Just my .02

 

thanks. i am still sticking with the 225/40/18

 

225/40/18 are even smaller than the 225/45/18's. Look on that link I posted and you will see just how much smaller.

 

I'm on Eibachs, no rubbing, and I drive the car HARD. There was a little rub mark on the inner fender of the drivers side, but it was almost nothing, just occasinal contact when leaning hard on the car, does not rub for me under normal conditions. I was running KDWs if it matters, some manufacturers measure differently, the KDWs have a huge shoulder, so if they cleared anything should. Just my personal experience.

 

theres peoples runnin 19's lowered with no issues, 235 and 18\s are fine

 

Id have to see it. Would love to run 235/40/18's on lowered with sportlines. Would realy need to see pics of tire gap an fender front and rear, also clearance between tire and strut.

 

I don't have any pictures of it anymore, and I went to a different tire last time to save money so I can't give current pictures, but it fit fine, looked great, really looked beefy and filled out the wheel wells more, looked perfect. I got compliments from my car buddies about how good it looked with the bigger tires on there and the drop. I'm going back on 235/40 KDWs when I change tires again, as long as I keep the 18" wheels.

 

Exactly....I'm also running 235/40/18 on 7.5" lowered on Sportlines. Just that little tiny spot Joe mentioned but you don't even notice it unless you search for it. I've never heard it either.

 

lol, 225 is literally the perfect width for a 7.5" wide wheel. I've worked in the tire industry for 7 years, and I've mounted countless tire/wheel combos. Hell, even the new SS/TC with 7.5" wide wheels has 225/40R18 tires. I guess if you want the tread of the tire to bulge past the lip of the wheel a little bit, 235's are fine, but 225's are definitely the perfect fit for 7.5".

 

That does look good and from all the numbers I looked at it is a smaller tire, except for the width (of course). So I dont see why they wouldnt fet well.

I too agree with you. But I think the 08/09 ss/tc has 8" wide wheels. In either case. From looking at the pics above it dosnt seem that the sidewall is bulging past the edge of the wheel.

 

The SS/TC has 7.5" wheels for sure. But anyway, yes the 235 won't bulge a ton or anything, and will still look good.

 

Im just torn on the 2 sizes. According to the tire sizing link I posted the 235's are only an 1" wider. If you divide that by 2 its then a 1/2" per side of each tire. The overall diameter and height is smaller. So according to the numbers I understand that the shouldnt rub. But any rub to me is not good. On my 04GTO tire/strut rub is the norm from the factory. And I hate it. (exwife drives that car).
Hey Kanowitz could you take a closer pic of the tire/fender to see the gap?