245 too big?
Premium Member
Joined: 10-09-2010
Posts: 14,420
From: Tacoma
No, Yes 
Especially if you pick these they run a tad narrow.http://www.tirerack.com/tires/tires....omCompare1=yes
Especially if you pick these they run a tad narrow.http://www.tirerack.com/tires/tires....omCompare1=yes
Premium Member
Joined: 10-09-2010
Posts: 14,420
From: Tacoma
It will fit inside the wheel well and turn fine, I'm running 255x40, they fit in there. I am only concerned that they go on the wheel and look good. I don't know about that brand if they are narrow or wide. Go mount one thats how to know for sure. You might ask the previous owner what width they had them on ?
Platinum Member
Joined: 01-09-2007
Posts: 16,081
From: SE USA
Sumos do run a tad taller that other brands, but don't seem wider at least in my case..
Platinum Member
Joined: 01-09-2007
Posts: 16,081
From: SE USA
Solman-
Because the 9.6" section width was measured on a 8.5" rim, section width will be a bit slimmer on your 7" Cobalt rims. They should fit just fine, imo !!! 245/40ZR18
Meas.Rim Width = 8.5"
Sect.Width = 9.6"
General rule of thumb is that tire section width changes by 0.2" for every 0.5" change in rim width, being reduced if mounted on narrower than measuring rim, and increased when mounted on wider rims.
Because the 9.6" section width was measured on a 8.5" rim, section width will be a bit slimmer on your 7" Cobalt rims. They should fit just fine, imo !!! 245/40ZR18
Meas.Rim Width = 8.5"
Sect.Width = 9.6"
General rule of thumb is that tire section width changes by 0.2" for every 0.5" change in rim width, being reduced if mounted on narrower than measuring rim, and increased when mounted on wider rims.
Last edited by sleeper; Jan 12, 2012 at 11:25 PM.
Senior Member
Joined: 09-05-2009
Posts: 452
From: New England
Instead of try to buy a tire around a sidewall number, buy a tire brand that you want, then just put on the biggest size, of that brand, that will fit properly
What sense does it make to buy an inferior tire just because it has a 245 on the sidewall, when there might be better tires out there that might just as wide with only a 225 sidewall number?
On one of my other cars I have 275s on the rear that are mich wider than some other brands 295s, but it seems like saying that you have a 275 is some type of bragging right to some. I personally would be embarrassed if I was bragging about tire size (which I would never od anyway), then someone came up to me and had a tire two number sizes smaller and still had a bigger footprint
Don't EVER buy tires using a sidewall number as the main factor. Buy it by brand first, then number. All manufacturer websites have recommended wheel and tire width charts and I would say they know 100x better than any of us, about what fits safely and properly
What sense does it make to buy an inferior tire just because it has a 245 on the sidewall, when there might be better tires out there that might just as wide with only a 225 sidewall number?
On one of my other cars I have 275s on the rear that are mich wider than some other brands 295s, but it seems like saying that you have a 275 is some type of bragging right to some. I personally would be embarrassed if I was bragging about tire size (which I would never od anyway), then someone came up to me and had a tire two number sizes smaller and still had a bigger footprint
Don't EVER buy tires using a sidewall number as the main factor. Buy it by brand first, then number. All manufacturer websites have recommended wheel and tire width charts and I would say they know 100x better than any of us, about what fits safely and properly
