Largest tires?
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I'm looking into replacing the rubber on my IS F. I know a common upgrade is to run 245's in the front and 275 in the rear. I was wondering if anyone has tried to run 285's.
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With FIGS setup you can go even wider in the rear. There are some 285s that will fit in the front as well.
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Going wider tires with 35/30 series tires F/R would result in a smaller overall diameter tire from my calculations. IIRC to match OEM diameter we'll need 255 fronts and 295 rears.
That's what's holding me back about widening in my upcoming tire change. Don't want to mess with the speedo/odo by changing tire diameters.
Lobuxracer, any thoughts on that?
That's what's holding me back about widening in my upcoming tire change. Don't want to mess with the speedo/odo by changing tire diameters.
Lobuxracer, any thoughts on that?
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Going wider tires with 35/30 series tires F/R would result in a smaller overall diameter tire from my calculations. IIRC to match OEM diameter we'll need 255 fronts and 295 rears.
That's what's holding me back about widening in my upcoming tire change. Don't want to mess with the speedo/odo by changing tire diameters.
Lobuxracer, any thoughts on that?
That's what's holding me back about widening in my upcoming tire change. Don't want to mess with the speedo/odo by changing tire diameters.
Lobuxracer, any thoughts on that?
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Only the rears count for the speedo/odo functions. I proved this with the car on jackstands when I was bedding the rear brakes (it's really hard to get them hot while driving, even on the track). Yes, the 295 is the ideal width, but without the right wheels, you'll be hard pressed to get them on the car without cutting or rolling the fenders.
I'm a huge fan of maintaining the OEM diameter for a bunch of reasons, not the least of which is the VDIM will still work correctly. It's hard to say if it will or won't with different sizes, but normally in the industry if you are +/- 2% you're considered OK.
For the front, a 255/35/19 and a 295/30/19 will be the same rolling diameter as the OEM 225/40/19.
For the rear, the only exact equivalent is 295/30/19. Everything else is a little one way or the other.
275/35/19 is 2% smaller, so it's considered acceptable, but not ideal.
I'm a huge fan of maintaining the OEM diameter for a bunch of reasons, not the least of which is the VDIM will still work correctly. It's hard to say if it will or won't with different sizes, but normally in the industry if you are +/- 2% you're considered OK.
For the front, a 255/35/19 and a 295/30/19 will be the same rolling diameter as the OEM 225/40/19.
For the rear, the only exact equivalent is 295/30/19. Everything else is a little one way or the other.
275/35/19 is 2% smaller, so it's considered acceptable, but not ideal.
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The 245/285 combo is .2" shorter in OD than the stock sizes, 25.8" vs 26.0". That's a difference of less than 1%, 3/4% to be exact. As with the 225/255 stockers combo, the 245/285 combo has the same ODs front to rear.
Lou
Last edited by flowrider; 06-28-12 at 04:22 PM.
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