What PSI do you guys run with 235/40/18s?

[A4orce84]

As the subject states, curious what air pressure people run with 235/40/18s tires?

I generally do:
Front - 42
Rear - 40

What's everyone 'recommended' values?

Thanks,
Asif

[claudiovagkraft]

I follow the door jam :)

[ADCS]

40+ is super high... that must be terribly uncomfortable lol

I vary 35-38psi depending on load in the car. More importantly, use a GOOD gauge to set your pressure... they are definitely not all equal. Call me old school but I will only use an analog gauge.

[19jdog]

I run 225 40 18 35-38 psi

[imnuts]

I follow the door jam :)

^That. I'll adjust up if I'm taking long highway trips, but it is typically somewhere between 35-38 psi, and I'd set them at that regardless of tire/wheel size. If I got much bigger wheels, I may drop it down a couple psi, but probably not much.

[Kevin C]

http://www.audizine.com/forum/poll.p...do=showresults

Interesting poll

[walky_talky20]

I usually run 38 up front and 36 in the back for most of my wheel setups. I do mostly highway.

I found that the wear is pretty even, but when I get to the very last bit of tread (2/32" and less) it is apparent the center is wearing a little more than the outside. So I may back it down to 36 Front / 34 Rear or so.

[Matt Devo]

38 psi all around, warm

[w0ady]

35-36 all around.

[old guy]

Seems my Conti DWS wears extra if PSI is set higher than ~34 cold. Not sure if alignment-related.

I have been experimenting with suspension settings and tire temperatures for some time. Here's an earlier thread that I posted as I was trying to determine the optimun alignment settings and tire pressures for the best combination of tire wear and performance. Clicky click®

Since then I have come up with what works best for me for both alignment settings and tire pressures. Clicky click® I got 50K miles out of my last set of Conti DWS and will get at least that much out of my current set.

The optimum pressure that works for me is 35 psi (cold) front and rear. I can go lower and the temperature gradient gets slightly better but I can feel the difference in handling. Here's what my last set of DWS looked like at just under 50K miles. The center was wearing slightly faster than the edges. Note the lack of inner edge tire wear even with high camber. That's where the bump steer (raised toe) and minimal toe in settings combined with tire pressures comes into play.

[mauromj]

I run 50psi front and rear on 215/40/18. Thats just because they are on 18x9.5's however lol.

[A4orce84]

Hey Guys,

Sorry to bump this thread up from the dead, but now with the cooler temperatures, I've been doing some more research on tire pressure and what specific PSIs to run. Looking at Michelin's website below, I just read something new to me:

Link:
http://www.michelinman.com/US/en/hel...are.html#tab-2

Interesting Tidbit:
"If the tire is hot, add 4-5 psi to the car manufacturer's recommended pressure value (0.3 bar) or wait until it has cooled down, which is an average of three hours after parking the car."

Maybe this isn't new to some of you on here, but looking above at some people checking their air pressure with 'warm / hot' tires, you might want to add a few additional PSI it seems. I just filled mine to be 40PSI (hot) all around, which when cool would be around the 35-36PSI range it sounds.

Anyway, just food for thought and good tip for those who might not have access to adjust their tire air pressure close to home.


Thanks,
Asif

[seanf86]

I set mine 35-36 psi cold. I always keep a guage in my center console and always check before hitting the highway. After having a tire blow out at 110 km/h I'm very careful about watching my pressures.

[Nollywood]

I run 42psi all round.

[old guy]

I run 42psi all round.

Why? (Serious question)

[A4orce84]

Maybe it's with a warm (hot) tire all the way around, which would make sense...

[Nollywood]

Why? (Serious question)

Because, that's the specified tyre pressures on my car, unladen. Laden pressures are actually 45psi all round.

- - - Updated - - -

Maybe it's with a warm (hot) tire all the way around, which would make sense...

Does anyone who knows about tyres and pressures, check them hot?

[ADCS]

No, never check them hot. Always cold before you drive it. Also don't check them in direct sunlight as that can vary the pressure 3psi per tire depending which way the Sun is beating on the car.

[MoparFreak69]

I run them until they look like they're bulging then just pump a ton of air into them till they don't bulge anymore.








J/k. My current tires are happiest at 32psi F/R

[A4orce84]

No, never check them hot. Always cold before you drive it.

I think you can, just as long as you know to compensate with an additional 3-4PSI due to having a hot tire. Some of us on here don't have a compressor at home, so I have to go to the nearby discount tire or gas station a few miles away with my tire gauge and adjust the pressure from there. By the time I get there (3-4 miles away), things have already heated up from a tire perspective.