Choosing the Right Size Tire

[josh.riffe13]

sorry if this has already been posted!!!! but what is the widest size tire that will fit on an 18in wheel without having to take out the wheel well stuff. and what would the dimensions be?

[josh.riffe13]

i want an 18x8 whats the best size tire to use for performance?

[Sean486]

Originally Posted by Tire Guy

This list has been thoroughly researched. If you don't see a size listed here (ie 215/45R17), then it is not recommended for the US-spec 6.

17" (original equipment wheel is 17x7)

215/50R17 6.0"-7.5" 32 psi (93+ load index), 33 psi (91 load index) *original equipment size*
225/45R17 7.0"-8.5" 35 psi
225/50R17 6.0"-8.0" 32 psi
235/45R17 7.5"-9.0" 32 psi
245/45R17 7.5"-9.0" 32 psi

NOTE: Section widths of 235 and above will probably require fender rolling. Check the offset of your wheels carefully before purchasing replacement tires. I was going to also include the overall diameter for each tire, but this can vary from manufacturer to manufacturer by .1-.2". Suffice to say that these tires fall within the "-2%, +3%" rule, meaning they are not more than 2% smaller or 3% larger than the original equipment tires, which have an overall diameter of 25.5 inches.

TAKE NOTE: When selecting replacement wheels and tires, the relationship of the wheel width to tire section width is very important! For maximum handling benefit, mount the tire on the widest wheel that size will allow. Mounting a tire on the narrowest width allowed will give better ride comfort, but won't give the best handling. In many cases, handling may be worse than before by mounting a wider tire on a narrow rim (ie. 235/40R18 on an 8 inch wide wheel vs. 215/45R18 on an 8 inch). Installing wider tires on your 6 will likely yield a handling improvement only if you have a wheel wide enough to take advantage of the extra tire width.

Sorry if this has been covered somewhere in the 27 pages of this thread, but I was wondering if somebody could tell me exactly why 215/45R17 is not recommended. I see a good deal on Craigslist for a set of snow tires this size. I thought they would work being only slightly smaller.

[Mz6GreyGhost]

Originally Posted by Sean486

Sorry if this has been covered somewhere in the 27 pages of this thread, but I was wondering if somebody could tell me exactly why 215/45R17 is not recommended. I see a good deal on Craigslist for a set of snow tires this size. I thought they would work being only slightly smaller.

The 215/45s are above the 3% difference from the OEM size. Basically, when your speedo says you're doing 60 MPH, you're actually doing 58. That may seem well to keep you from getting a speeding ticket, but you'll also get inaccurate odometer readings as well.

[ZoomZoom04]

I have these on my 6 and they have held up for about a year and a half, but the ride is a bit on the rough side (they weren't very expensive tires to begin with) but if you go to any tire place, some will tell you that they will not install that size on our stock wheel. That is below the required load index rating and may be more prone to a blow-out while driving.

[Stompjrkz400]

can i run 245/45r18's with a 7.5inch rim and +42 offset? i hope someone chimes in beacsue im going to pickup the tires today hopefully

[tank1707]

Originally Posted by Stompjrkz400

can i run 245/45r18's with a 7.5inch rim and +42 offset? i hope someone chimes in beacsue im going to pickup the tires today hopefully

That should be fine. If your lowered or have a heavy load in the back you might experience a slight rub but nothing extreme.
I ran a 18x8 with 245/40/18 with +35 and it rubbed when I had a heavy load but not always. So those shouldn't be a problem worst comes to worst roll the fenders and its an easy fix.

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[Stompjrkz400]

Originally Posted by tank1707

That should be fine. If your lowered or have a heavy load in the back you might experience a slight rub but nothing extreme.
I ran a 18x8 with 245/40/18 with +35 and it rubbed when I had a heavy load but not always. So those shouldn't be a problem worst comes to worst roll the fenders and its an easy fix.

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awesome, no lowering, infact i just stiffend the rear end and lifted it to compensate for spring sage, thanks

[Stompjrkz400]

nevermind deal fell through all the guy has is 235/55/18's and im really sure that 55's will scrap like crazy