I know this has been talked about and posted many times but for some reason i can not view the pictures of ted's 275's on his stock 18's i am think ing about doing this setup but dont know how they look. If possible can any of you guys directly post the pictures on the thread instead of making it a link. I NEED TO SEE THESE CUZ I WILL BE IN NEED OF TRACTION WITHIN A COUPLE OF WEEKS. NITROUS!!!!!!

THANKS AGAIN!

 

275 will never ever fit on the stock 18" wheels, they are nowherte near wide enough to fit it! !!

 

iLLG35

Ya, they will, but that's the major problem. They "fit", if you want to call it that, but have severe tire buldge that is not healthy for the tire or the handling of the car. People have done it, and have bragged about it. However it's a bad, very bad, idea. The stock 18s are 8" wide, and the very widest tire that should go on these wheels is 255/45/18. For the 275/40/18, all tire manufacturers recommend a rim width range of 9" to 11", with the optimal width being 9.5". If something should happen (tire rolls of the rim or whatever) you would be left in the cold because you did not follow the tire makers recommendations. Any good tire shop should refuse to install such a wide tire on an 8" rim, but I guess some don't.

Lou

 

Could not have said it better, the 275's will fit on the 8" but you will not get better traction or handling it will be WORSE. My friend did it on his wheels on a Z and they dont look to good with tires buldging out the side go 255.

 

yeah.. i agree with what everyone has said so far.. definitely DO NOT do this.. i remember seeing another member having this 275s on his stock 18s and he was all proud of it.. needless to say, it looked like CRAP.. too much bulge and no improvement in handling/performance.. if you want 275s on the rear, just suck it up and get new rims.. simple as that..

 

so what's the recommended tire size for 10 to 10.5 inch wide rims?

 

For the rear tires I have gone by the standard 75-85% wheel/tire width ratio. If the wheels in question are 8" wide (203mm) then here are the wheel/tire width ratios for the following tires (note this is not the same thing as tire aspect ratio)

203/235 = 86%
203/245 = 83%
203/255 = 80%
203/265 = 77%
203/275 = 74%

So it looks to me like the 255's are probably the best fitting tire, with the 245's and the 265's being safe alternatives.

 

Using the above rules as a guide for 10" I would say 315's are optimal, and for 10.5" it would be 335's. As the wheels get wider you have more increments to play with in the safe range so you have more options above and below these optimal sizes...

 

thanks a lot for the advice now the ? is with 265 what aspect ratio should i get to keep it as close to stock as possible.

 

NO

One guys opinion and your off to buy 265s? Again - Tire manufacturers recommend nothing more than 255 for a low profile tire on an 8" rim. 265 low profile is recommended for a 9" to 10.5" rim with 9.5" being optimal. Stay with the 255/45/18 in back, if your interested, I would go with 245/40/18 in front. This combo will lessen understeer, and give you the wide look in the rear that you want. If you want to see how a 255 looks, go to a BMW dealer and check out an M3. The put 255/40s on a 9" wide 18" wheel. They look pretty aggressive to me.

Lou

 

How does this differ from the general rule I just gave? In case you didn't know tire manufacturers only recommend a very narrow range of optimal sizes, but in reality there is a larger "safe" range of tires available for any rim width that people have been using for decades without any problems. As I said, 255's are probably best, but 265's are a safe alternative. If you can prove that the 265's are not a safe alternative then I'm all eyes...

 

here are my 255/45 r17 on stock rims

 

more pictures...

michelin pilot sports... i like them much better than the goodyears it came with!!

 

Using the simple formula: (aspect ratio * width = height)

Stock 18x8 tires: 245/45/18, tire height = (.45 * 245 = 110)

So if your concern is your speedo being off, you want your new tires to have the same height which is 110. Using the same forumla for the 265's:

( X * 265 = 110 ) where X is the aspect ratio

To solve for X simply divide 110 by 265 and get .414 so that means you would want a 265/40/18 tire. Just keep in mind that sometimes a particular size may not be available so you will just have to settle for the speedo being a little off as well as lowering or raising the car at that axle slightly depending on which tire you select.