tire and wheel staggered - Fourth Generation Pontiac Firebird (1993 - 2002) - Firebird Nation

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tire and wheel staggered

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#1 richard r

richard r

    Firebird Tire Changer

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Posted 15 March 2020 - 06:23 AM

Hello, everyone its been a couple of years since i have posted anything. I am in need of some tire and wheel combo information. I am look at putting 17x9.5 rim on the front with a 245/48r17 tire and, 17x11 315/45r17 rear. My question is will this combination work with out rolling the rear fenders and, how will drive ability be any and all suggestion welcomed have a nice day. 

#2 Injuneer


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Posted 15 March 2020 - 07:49 AM

If you really want a 245/45-17 (25.7" diameter) tire in the front (there is no "48" section width), the typical suggested wheel width is 7.5" to 9.0".  A 9.5" wheel is generally too wide (check the specs for the specific brand and model tire you are looking at), and may cause the tire to look "stretched", or even cause excessive flexing and heat buildup.  A better tire for a 9.5" wide wheel would be a 275/40-17 (25.7").  For a 9.5" wide wheel, the offset needs to be in the range of 45-56mm.  I have run 49mm and 56mm offset 17x9.5's with no problems.


The 17x11" rear wheel requires an offset in the range of 45-50mm.  For the tires.... I don't think I have ever seen a 315/45-17 street tire.  That would be a 28.0" diameter, and will barely fit in the wheel well.  Most people opt for a 315/35-17 (25.7").  I run the 315/35's and while I agree that a slightly larger diameter would fill the wheel wells better, I'm not aware of a size that will accomplish that.


If you opt for the 315/45, you will need to have the PCM programmed for the new tire diameter, or your speedo and odometer will read ~9% lower than actual speed and miles driven.  Depends whether your car had the 235/55-16 (26.1") or 245/50-16 (25.7") tires from the factory.  The large mismatch between the front and rear tire diameters can also create problems with the ABS and TCS systems.


There are pics in my Gallery of the car with the 17x9.5/17x11 setup, and also with 28" slicks (required recentering the rear axle front-to rear, and cutting an inch off the rear bumper cover).  Some mods are required for the 315/35-17's in the back.


Also, see post #9 on this site:




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