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Stupid question about rear tire PSI

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Old Jan 7, 2011 | 12:57 PM
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Default Stupid question about rear tire PSI

Kind of a dumb question but would it hurt any to run the rear tires a few PSI less than the front because theres less weight on the back end, compared to the front?
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Old Jan 7, 2011 | 01:07 PM
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If ur looking for more traction you would want to lower the psi in the front tires but I wouldn't drive that way on the street.
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Old Jan 7, 2011 | 02:12 PM
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It hurts fuel economy and causes uneven tire wear, to have the tires low on air. The manufacturer had an engineer figure out what the tire pressure should be. Follow the recommendation.
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Old Jan 7, 2011 | 03:02 PM
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Originally Posted by mhurlbutjr
If ur looking for more traction you would want to lower the psi in the front tires but I wouldn't drive that way on the street.
That's not a very good rule for street tires. There is a PSI range within which the tire has a good contact patch, if you go below that your contact patch, and also traction, suffer. The PSI at which that happens varies by tire model and axle weight, but it's usually somewhere around 25-30PSI for most street tires on most cars that I have experience with. Often even if you're not losing contact patch due to low PSI you will get better traction with a higher PSI...in my experience somewhere between 30 and 40 PSI depending on tire, car, and FWD/RWD.



For lateral and braking traction if your tires are up to temperature you will achieve the best handling with staggered tire pressures. When I autox the Accent I usually settle on around 42PSI in the front and 32 PSI in the rear. I won't run that on the road though because I don't get good braking or lateral traction with the front end when the tires are cold.



For daily driving it would not hurt anything to be 1 or 2 PSI lower in the rear than the front. I also don't think you will notice much of a difference with that setup though.
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Old Jan 28, 2011 | 03:26 PM
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Experiment with your air pressures until you find a combo you like. Sometimes I vary the PSI between the front's and rear's by about .5 - 1 PSI depending on how I plan to drive the car or when I need to carry heavy stuff. I keep the tire pressures even all the way around for daily driving though. I usually run 32 - 33 PSI on my BFG g-Force Supersport A/S tires. Anything higher causes a rough ride and anything lower affects ride control.
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