Widest Tires For GT500 Rims

Benwhite911

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I just seem to be posting here non stop. But you all continue to be so helpful so I hope you don't mind. I just picked up a set up 2007-09 GT500 Rims, rim size 18X9.5. The come with P255/45 R18 tires in the front and P285/40 R18 tires in the rear. What I want to know is what is the widest set of rear tires I can get on these 18X9.5 rims and still maintain the same, or close to the same overall tire diameter?

Anyone know?
 

46addict

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295/40 will be very close to stock diameter and should fit without much fuss. A 305/40 or 305/35 should work too but there will be a 5/8" difference from stock, which is still negligible.

Tire manufacturers recommend a 10" width wheel for the three sizes mentioned, just FYI.
 
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stkjock

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Anyone know?

The search feature would........


also you have a V6, you don't need bigger than a 285 as it is

also please review the rules, this is not tech, its wheels/tires, moved
 

stkjock

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so you wan to go slower! got it!! :cheers:
 

Gabe

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You can easily fit 305/40/18 tires on there, I run that size drag radial on the back of my car with the 18x9.5 SVT wheels ... but yeah, like mentioned above, you really don't need a 285 or bigger tire at your power level
 

Norm Peterson

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I just seem to be posting here non stop. But you all continue to be so helpful so I hope you don't mind. I just picked up a set up 2007-09 GT500 Rims, rim size 18X9.5. The come with P255/45 R18 tires in the front and P285/40 R18 tires in the rear. What I want to know is what is the widest set of rear tires I can get on these 18X9.5 rims and still maintain the same, or close to the same overall tire diameter?

Anyone know?
285/40 is as wide as any tire mfr will want you to use on wheels that are only 9.5" wide.

Wider than that is possible but not generally recommended (you might be be on your own if it ever came to warrantying a tire used outside its min to max rim width range, and it will be somewhat less precise or well-behaved in the corners).

Keep in mind that when you squeeze a 295/xx down onto a 9.5" wide rim, it won't end up actually being a 295-wide tire. Closer to 289 or 290. A 305/xx tire will lose even more than 5 or 6 off its nominal width. IOW, you won't be gaining as much "appearance" as the bigger tire size suggests.


Just so you know, 255/45's on 9.5" wheels end up being about a 265-wide tire, so the earlier GT500's 255/285 size stagger was only about 265/280 in terms of the actual as-mounted measurements.


Norm
 
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BTD

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IMO I'd run 275/40 on them, but as others have said, you can fit 285's as well. Anything wider starts to get a bit pinched.
 

Norm Peterson

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Even 265/40-18 is a do-able size for those wheels. Note that you get about a 10mm "lowering" effect without affecting steering, suspension, or alignment AT ALL, plus effectively slightly shorter gearing (about like going from 3.55's to something midway from there to 3.73's if that makes any sense).

FWIW, perhaps the strongest card in the V6's hand is its cornering & handling potential (as strong as a GT's). Might be better to play more to the car's strength and leave people scratching their heads than chase an appearance that the car's actual performance would represent a let-down to.


265/40-18 MPSS on those GT500 wheels . . . with just over half an inch lowering via "lowering springs". 1" total with half of that in the tires is there but subtle. The tread width on those particular 265/40's is identical to that of their 'big brother' 285/35-18 at 10.2"

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Norm
 

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