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[rourkem]

What tire pressures would you recommend for general spirited driving? Assume I want to fine one level that works well enough for 100+ "casual" track driving but also general commuting which can be fast and agressive when overtaking people but generally settles to below 80mph.

I don't need a cushy road feel, but don't want a pressure setting that will negatively impact tire life in a big way. I also

[Elementary]

Who drives on the street casually at 100+?

Take it to a track, save a life and money in tickets.

[rourkem]

Originally Posted by Elementary

Who drives on the street casually at 100+?

Take it to a track, save a life and money in tickets.

Not I. I said I drove on a TRACK causally at 100+.

I say "casually" to differentiate from what I did 5 years ago when I had a separate set of tires at a very specific pressure for the track. I take it quite a bit less seriously now as it's more a fun thing to do and a way to enjoy my car at high speed in relative safety.

[luis_m3]

I set my PS2s to 35/36 (cold)... they feel good "to me" both at the track and DD.

[auggiem3]

Originally Posted by luis_m3

I set my PS2s to 35/36 (cold)... they feel good "to me" both at the track and DD.

How can you run your tires at a cold 35/36 on a track day?

My PS2s need to drop down to 20-22 cold psi to keep them below 40-42 hot psi on track runs.

I ran them at a cold 26-28 psi last year and tested to a scary 52 psi after two 20 minute track sessions on a mild day (60 degrees f).

If I would have started at 35, I would have well exceeded the maximum pressure and probably experienced a blowout assuming I didn't lose it from lack of grip...

[jphughan]

Originally Posted by auggiem3

How can you run your tires at a cold 35/36 on a track day?

My PS2s need to drop down to 20-22 cold psi to keep them below 40-42 hot psi on track runs.

I ran them at a cold 26-28 psi last year and tested to a scary 52 psi after two 20 minute track sessions on a mild day (60 degrees f).

If I would have started at 35, I would have well exceeded the maximum pressure and probably experienced a blowout assuming I didn't lose it from lack of grip...

You wouldn't have this problem if you used nitrogen rather than air. My dealer filled the tires with nitrogen for free, didn't even have to ask.

[luis_m3]

Originally Posted by auggiem3

How can you run your tires at a cold 35/36 on a track day?

My PS2s need to drop down to 20-22 cold psi to keep them below 40-42 hot psi on track runs.

I ran them at a cold 26-28 psi last year and tested to a scary 52 psi after two 20 minute track sessions on a mild day (60 degrees f).

If I would have started at 35, I would have well exceeded the maximum pressure and probably experienced a blowout assuming I didn't lose it from lack of grip...

I track at the Nurburgring and take 20-30min breaks between laps. Also, weather temp makes a difference (45-50 the last two times). The pressure went up to 44 after 4 laps during my last visit; that was the highest.

[Merked M3]

I do not like to get the pressures higher than 42 HOT. So a good starting point is 32 rear and 34/36 front. If you are doing any hard braking go with 34.

I am pretty OCD about tire pressures at events, and I can tell you from experience that once the PSI gets over 42 you will start to loose traction. It was a hot day and the car started cutting loose under trail braking; after lowering the pressures to 38 HOT I had better traction again.

[rourkem]

Interesting that there's such importance in temp when measuring. I remember that wen I used to fill to a specific temp for the track I used a small portable pump powered from the cig lighter outlet to make sure I was measuring the "cold" level.

I'm a bit less anal now and generally drive the ten blocks of so to a service station and fill it up then. Should I consider that a hot, cold or in-between temp? Would it be better for me to fill up after driving a bit more?

[elh0102]

Almost every high performance street tire I have used on cars of generally balanced weight distribution have worked well at around 38 hot. Obviously, cold pressure will vary greatly, depending on temperature and use. If I’m checking pressures cold, for street use, I’ll usually set them at 35. For track, starting pressure could be in the upper 20’s to low 30’s.

[persian54]

For my CS3s, I ran 32-33 cold if it wasn't hot out, and reached about 40hot

if it was hot, i would run about 31cold

on my RS3s, I run 29 cold to reach a 40 hot
Dropped to 27 cold but it still went to 40 hot lol.

[Merked M3]

Originally Posted by rourkem

Interesting that there's such importance in temp when measuring. I remember that wen I used to fill to a specific temp for the track I used a small portable pump powered from the cig lighter outlet to make sure I was measuring the "cold" level.

I'm a bit less anal now and generally drive the ten blocks of so to a service station and fill it up then. Should I consider that a hot, cold or in-between temp? Would it be better for me to fill up after driving a bit more?

10 blocks is "cold" especially if it's just city driving. You could always check the pressures when you leave the house and when you get there, minus whatever they heated for the true cold temp, and that would be the ultimate M3 nerd solution.

"Hot" would be after 30 minutes of driving including some highway OR just a few minutes of spirited driving w/ hard braking and acceleration. Once on a sunny day I heated up my tires from 32r/36f to 38r/42f in literally 1min30seconds because there was a large braking zone (was competition.)

[ShadeD1]

On Hoosier R6 34-35 hot
On Yokohama AD08 38 hot

[Ateam]

Originally Posted by auggiem3

How can you run your tires at a cold 35/36 on a track day?

My PS2s need to drop down to 20-22 cold psi to keep them below 40-42 hot psi on track runs.

I ran them at a cold 26-28 psi last year and tested to a scary 52 psi after two 20 minute track sessions on a mild day (60 degrees f).

If I would have started at 35, I would have well exceeded the maximum pressure and probably experienced a blowout assuming I didn't lose it from lack of grip...

Just so everyone knows the usual 50 or 52 listed on a tire as "max" psi is a COLD psi value. 50 is not the max when it is a hot temperature. Not saying you run it to 50 cold but a tires "max" when hot is much closer to 75 psi range as they are pretty conservative when listing a max cold psi.

Also never heard so many people using "hot" psi measurements to guage tire pressure. Bmw specifies 35 psi cold on all 4 corners

[ShadeD1]

Originally Posted by Ateam

Also never heard so many people using "hot" psi measurements to guage tire pressure. Bmw specifies 35 psi cold on all 4 corners

track junkies doing DE's usually measure their tire pressures after a 20-30 min run session. I find that my car feels best to me if I come off track at around 38 psi on street tires and 34 psi on slicks. Of course YMMV

[luis_m3]

Originally Posted by Ateam

Just so everyone knows the usual 50 or 52 listed on a tire as "max" psi is a COLD psi value. 50 is not the max when it is a hot temperature.

I did not know that... good info! I always go by cold anyways, and check the pressure after a couple of laps around the track; just in case I guess.

[Ateam]

Originally Posted by ShadeD1

track junkies doing DE's usually measure their tire pressures after a 20-30 min run session. I find that my car feels best to me if I come off track at around 38 psi on street tires and 34 psi on slicks. Of course YMMV

Thanks I did not know that is what the track people do! For regular non-track driving its typically the "cold" psi people go by and what is reccomended. Guess it makes more sense on the track because depending on how hard you push the car, the hot psi could vary quite a bit, whereas on the street you are probably pretty consistently getting the same "warm" temperature and psi in your tires as there is limits to city driving.

[klammer]

I run around 40-42 hot on AD08's on track, anything over that and the wheels get a bit greasy on track. Our cars are sooo sensitive to tire pressure that it is really a personal preference thing. Took me a full year of track days (20 events) to really dial this in for me, but man, when you get that right, neutral setup, this car can just take a beating on track. Street driving I usually just add a few PSI as I will NEVER get my tires as hot off track as I will on. In response to those that run really low PSI and still get high hot readings, have heard that under inflating adds more rolling resistance and the like which can heat up the tires faster and hotter than a higher more proper temp. Just like our M's it's about balance and precision, might take some time, but just another way to really learn/know our cars, just another level of connection, enjoy

[asw19]

My local dealer in Houston just returned my car to me after scheduled service with my front left tire at 72PSI.

The car was pulling to the right and the road noise was noticably higher, so I let some air out...didnt have a guage. Still pulling right so I let out more. At this point I was just guessing high pressure because they added air to that tire right before I left.

When I got home I put the guage on it and it was 69PSI after letting the air out.

[auggiem3]

Originally Posted by klammer

I run around 40-42 hot on AD08's on track, anything over that and the wheels get a bit greasy on track. Our cars are sooo sensitive to tire pressure that it is really a personal preference thing. Took me a full year of track days (20 events) to really dial this in for me, but man, when you get that right, neutral setup, this car can just take a beating on track. Street driving I usually just add a few PSI as I will NEVER get my tires as hot off track as I will on. In response to those that run really low PSI and still get high hot readings, have heard that under inflating adds more rolling resistance and the like which can heat up the tires faster and hotter than a higher more proper temp. Just like our M's it's about balance and precision, might take some time, but just another way to really learn/know our cars, just another level of connection, enjoy

Thanks Klammer - so many variables impact pressure (ambient temp, track temp, weight deltas associated with instructors, driving styles and most obviously the track itself).

I agree that something in the hot high 30s feels best on my e92 but I backed into my cold pressure the old fashioned way....ran sessions and released hot air until I got it to the right feel (about 38-40 hot psi). Then let her cool off over night and tested cold in the am (actually TPS went off before I even got out of the parking lot)....22 cold on all 4 corners.

[Mr. ///M3 RD]

Originally Posted by rourkem

What tire pressures would you recommend for general spirited driving? Assume I want to fine one level that works well enough for 100+ "casual" track driving but also general commuting which can be fast and agressive when overtaking people but generally settles to below 80mph.

I don't need a cushy road feel, but don't want a pressure setting that will negatively impact tire life in a big way. I also

I recommend driving normal on the streets and when on the track use track wheels and tires and talk to other track fellows driving similar or the same car as yours ... driving on streets like you describe is not legal and eventually you might hurt yourself or someone else.

Besides you give all of us a bad name if you drive reckless on the street.

[sarddenso]

Originally Posted by asw19

My local dealer in Houston just returned my car to me after scheduled service with my front left tire at 72PSI.

The car was pulling to the right and the road noise was noticably higher, so I let some air out...didnt have a guage. Still pulling right so I let out more. At this point I was just guessing high pressure because they added air to that tire right before I left.

When I got home I put the guage on it and it was 69PSI after letting the air out.

Glad you made it home ok!
I know on PS2's they say 50PSI max!