Need tire size help on 275/285's (35 or 40) 18"

[matt01ss]

Well I have 285/35/18 Nitto 555's on my 01 SS now and am stuck whether to get the same or downsize on my rep ZO6 18x9.5's..My question is if I were to downsize to 275's which is a better fit?? 275/35/18 or 275/40/18's? I remember getting the size I have not for the better sidewall cushion but am not sure with the 17's..thanks for the help

[mrr23]

you are confusing me. you list 18" tires, but then ask about 17" tires.

[Hot Black Trans-Am]

I did 275/35 up front and 285/35 in back and I like it. Only prob is you can't rotate them easy, but the rears go quick anyway.

[matt01ss]

shoot sorry when I said 17" I meant to write 275..and yes I would like to rotate the tires so my question really becomes down to if I were to go down a size to 275's which would work better on a 18x9.5 rim - 275/35/18 or 275/40/18? Another would be, are 285's a better fit on a 18x9.5 rim or would 17's work alright?

[Eugenio_SS]

assuming you meant 275 instead of 17 (again)...
a 275 will fit better on a 9.5" wheel than a 285.
I would actually get 275/35-18 all around and not go w/ a 40 ratio, which makes the tire 1" taller than stock overall diameter... going w/ a 275/35-18, you'll keep the same OD

[mrr23]

they will both work on the rim. the 35 series is 25.5" tall and the 40 series is 26.6" tall. so, the speedo will be off going to the 275/40-18

Another would be, are 285's a better fit on a 18x9.5 rim or would 17's work alright?

are you trying to ask if going to 17" wheels will work??????

the difference between the 275 and the 285 is 10mm. just less than 1/2" width change. up to you what you want to put on.

[davidz28guy]

imo 275/40s looks better, fill the well nicer, when i had 275/35 i didnt care for how it looked, not enough sidewall, you could always go 295/35 on the back, :yup: but then you cant rotate them

[Eugenio_SS]

imo 275/40s looks better, fill the well nicer, when i had 275/35 i didnt care for how it looked, not enough sidewall, you could always go 295/35 on the back, :yup: but then you cant rotate them

you can rotate w/ 295s... but that would require 18x10.5
Those fit allround...
you can fit wider wheels in the front w/ less issues than in the back ;)

[davidz28guy]

why would you need 10.5? 295s fit on a 9.5 rim, is it something to do with the fronts?

[Eugenio_SS]

why would you need 10.5? 295s fit on a 9.5 rim, is it something to do with the fronts?

they fit but the tire isn't properly mounted/bedded on the wheel.
275 is pretty much the maximum you should be putting on a 18x9.5

The same way there are ppl putting 315s on stock sized rims... 315s are meant to be mounted on 11-13" wide rims.

[Mr. Anderson]

shoot sorry when I said 17" I meant to write 275..and yes I would like to rotate the tires so my question really becomes down to if I were to go down a size to 275's which would work better on a 18x9.5 rim - 275/35/18 or 275/40/18? Another would be, are 285's a better fit on a 18x9.5 rim or would 17's work alright?

Matt you're funny! You're bound and determined to get a 17" tire to fit on an 18" rim. Just kidding.

When I ordered my 18x9.5 rims, I was told that 285/35's would be a "bit" too wide for the rim. I know it's only 10 mm difference but I didn't want to take a chance on how they would look. But I should have remembered that The Tire Rack is ALWAYS conservative on their recommendations that are "outside" of stock.

After I got them I thought 285/35's would have been fine. In fact, my new wheels are 1/2' wider than stock, which is approx. 12.5 mm and 285's are 10mm wider than 275's so I think it would have been a better fit than a narrower tire (275) on a wider rim (9.5), the overall diameter would have change, but by less than a 1/4".

Maybe I'm all screwed up.


But I'm happy with them.

[davidz28guy]

my 295s went on and look good, thats what ive always been told the max is on a 9.5 rim

[Hot Black Trans-Am]

To me my 275's fit good, but the 285's look a little meatier and fit a little better. They are not squeezed on as much as the 275 are stretched. Not that they are either way really. The actuall physical sizes change a little with manufacture and model of tires also. Some are bit bigger or smaller than others of the same sizes. I don't see any problems with a 275-295, but I wouldn't go smaller or larger than that. In spring I'm going to try my 285's up front and see how they fit.

[99zman]

To me my 275's fit good, but the 285's look a little meatier and fit a little better. They are not squeezed on as much as the 275 are stretched. Not that they are either way really. The actuall physical sizes change a little with manufacture and model of tires also. Some are bit bigger or smaller than others of the same sizes. I don't see any problems with a 275-295, but I wouldn't go smaller or larger than that. In spring I'm going to try my 285's up front and see how they fit.
i just ordered 285/35/18 for all 4 tires there going on 18x9.5 privat profil's do you have any pics of your 285's in the rear. thanks.

[Hot Black Trans-Am]

The car was very dirty due to it raining for a a week, but the first is the 285 in the rear and the 2nd is the 275 up front.

[99zman]

Thanks for the pics man. you can barely tell a difference in the sidewall height. thanks again.