[JustinHEMI]

What tire pressure is everyone running?

Yes, I know "door card" is the easy answer but it's more complicated for our car. There's < 100 setting, on the door card, and there's > 100 setting in the manual. They also include optional tire sizes in the manuals table.

If you select > 100 in the idrive tire settings, but keep pressure at door card value, the car will tell you that you have low pressure.

Obviously on the street none of us are running over 100 for sustained periods so there's probably nothing wrong with sticking with the < 100 values.

However, for those of us that mostly drive spiritedly, I'm wondering if there's a better place to put pressure between those values. Especially considering my now wider than OEM tires.

I'm thinking of trying 34 front 38 rear.

[JustinHEMI]

Just ran around with 34/36 cold (66f) and felt great at 105F 38/40.

[Sherlock997]

I would say try to aim for a 35F/36R hot which usually works pretty well for spirited driving. I don't have mine yet so I can't speak for temps but on a 200tw, eg. Yokohama A052/Falken RT660, I usually run 28psi cold but I am auto-crossing or tracking so it winds up being around 35psi hot on a square tire setup. On the street, 32psi cold is what I usually set my M240i on PS4S at.

[jadatis]

Tirepressure advice is all about load on tire and maximum speed used, wich you wont go over for even a minute.

I determined that using 90% average on axle of loadcapacity calculated for the pressure for 160kmph/99mph ( make it 100) gives maximum reserve, but still acceptable comfort and gripp. The 160kmph/99mph is the referencespeed of tires with speedcode Q to V.
For reference-speed and - pressure the maxload of tire is given on sidewall.

If you determine that for your axleloads in normal use, you can drive upto 99mph without overheating your tires. Thats the main goal of pressure determination.

Then if that once you have to pick up a load of stones 20 miles away, this pressure is still safe, if you drive only 50mph.

The most tricky part is to determine the axelloads 99% acurate, and only done by weighing per axle.

Once you did that in your loadingsituation, I can make a pressure/axleload-list for your used tires, customised for your used max speed.

Then if you keep in mind to lower the speed drastically, when incidental heavy load, you dont need to highen up the pressure.

When on long trips fully loaded and when towing, then determine needed pressure for GAWR's and behind mayby even overloaded.

And that is what carmaker tries to achieve with the 3 pages of pressure info.
They determined for instance axleloads for 3 persons and a little load, and calculated with some reserve the pressure for upto the 99mph, and max technical carspeed (mayby even 150mph).
For fully loaded GAWR's are used.