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Discussion Starter · #1 ·
Just wondering I'm running Dunlop Sport Maxx Rts 235/40r18 with a max tire pressure of 50psi. I'm running them at about 36psi right now. What is the best psi to run tires at for performance driving?
 

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I try to keep mine around 38-40 psi in my PSSs. I wouldn't ever keep it at the max allowable pressure.
 

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You don't want to little or too much tire pressure because you'll end up having uneven tire wear and you'll end up having to replace them for frequently. If you're doing an autox event or going to the strip you can let some out for better traction though.
 

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Set to the manufacture spec in the driver door jam. Check 1-2 times a month. Always set the pressures while the tire is cold. You don't want to do it after been driving since the pressure will increase with the heat.

Only other time you need to mess with pressures is for track duty and your experimenting for better traction with a lower pressure.
 

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Discussion Starter · #8 ·
Thanks guys. I'm running my stock Perelli all seasons right now on stock wheels... gonna throw my Dunlops back on in the spring and when they wear out I think I'm gonna splurge in some Michelin PSS. What the perk in having a 245 or 255 as opposed to 235? Thinking about going 245/40r18 next time round.
 

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I like to run a little higher than spec. Running 39F/38R right now with the stock F1's. I like it but 38F/37R might end up being the sweet spot for me. I've run 40F/39R before but I think anything over 40PSI is too much.
 

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Thanks guys. I'm running my stock Perelli all seasons right now on stock wheels... gonna throw my Dunlops back on in the spring and when they wear out I think I'm gonna splurge in some Michelin PSS. What the perk in having a 245 or 255 as opposed to 235? Thinking about going 245/40r18 next time round.
The PSSs are a great decision. I will be going with those again when it's time to replace mine. I will probably go with 245s also, but not sure how much, if any difference at all, it will make, but given that I'm traction limited in the first couple gears right now I'm willing to experiment and go up a size. Anything more than that would be overkill, you won't necessarily get any more rubber on the road, you're just going to end up with tires that have to "bunch" somewhat to make them fit, which you don't want.
 

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I run 40 PSI on street usually to reduce tire wear. For autocross 34-36, but start higher and work down while paying attention to sidewall roll since it varies by tire. The F1s love to roll over :(
 

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Whats the benefit of having higher pressure? I dont know anything about tires... trying to learn.
More pressure leads to a smaller contact patch on the tire. So less of the tire is touching the road. That being said, you can see slightly better gas mileage because you are reducing the rolling resistance of the tire due to many different factors, but basically because you have less tire contact.

Tires are their design are a lot more complicated than one would think. The amount if engineering that goes into them is jaw dropping.
 
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