[Westside Guy]

My M40i has Michelin's 19 inch Pilot Super Sport tires and the label inside of the driver's door recommends 32 pounds of pressure when they are cold for both the front and the rear tires. 32 pounds sounds low, is that the amount of air pressure that you folks are using for your Z4's?

[TAZ007]

Manual says 38F/40R and dealer delivered with 40 all around. Go by the manual.

[Westside Guy]

Originally Posted by TAZ007

Manual says 38F/40R and dealer delivered with 40 all around. Go by the manual.

I am basing this on driving under 100 mph.

On page 262 of my 2022 manual it say 32 pounds for the 19 inch tires on the M40i which is what the label on the door reads.

I searched the settings in the car this afternoon and it says if I am driving under 100mph the 19 inch tires (cold temperature) should be 31 pounds.

My local repair shop owner who has an M3 said if this was his car he would fill them up to 34 pounds and now the manual is giving you much higher numbers.

[TAZ007]

Originally Posted by Westside Guy

I am basing this on driving under 100 mph.

On page 262 of my 2022 manual it say 32 pounds for the 19 inch tires on the M40i which is what the label on the door reads.

I searched the settings in the car this afternoon and it says if I am driving under 100mph the 19 inch tires (cold temperature) should be 31 pounds.

My local repair shop owner who has an M3 said if this was his car he would fill them up to 34 pounds and now the manual is giving you much higher numbers.

I feel your pain, door has 34; but manual had 38/40 on my 2021. So much for consistency.

[Westside Guy]

Originally Posted by TAZ007

I feel your pain, door has 34; but manual had 38/40 on my 2021. So much for consistency.

Do you have the 18 or 19 inch tires on your 2021? Also are they the Michelin Pilot Super Sports that they are shipping on the 2022's?

[TAZ007]

Originally Posted by Westside Guy

Do you have the 18 or 19 inch tires on your 2021? Also are they the Michelin Pilot Super Sports that they are shipping on the 2022's?

Running 19's. I just received the car in early August and only have 850 miles on it. Not sure why the change in the manual, but I recall seeing different pressure settings for different loads which makes sense.

[Westside Guy]

Here is the page from my manual for under 100 mph driving.

[TAZ007]

Originally Posted by Westside Guy

Here is the page from my manual for under 100 mph driving.

Agree, it seems low. The tire is safe up to 50 so determine what you like and run with it.

[Westside Guy]

Originally Posted by TAZ007

Agree, it seems low. The tire is safe up to 50 so determine what you like and run with it.

I will probably go with 34 pounds which is what the owner of my local repair shop recommended. He used to work for a BMW dealership and now the majority of the cars he services in his own shop are either BMW's or Mercedes.

[MG 228i]

been running 32 F/R for ~14k miles, wear looks normal.
more grip off the line at 32 PSI

[Westside Guy]

Originally Posted by MG 228i

been running 32 F/R for ~14k miles, wear looks normal.
more grip off the line at 32 PSI

Can I assume you have the 19 inch Michelin Pilot Super Sports and not the 18 inch tires?

[Kwajtrader]

I have a 2021 M40i with 19” Pilot SS tires and the manual is the same as what you posted: 32 front/rear. That’s what mine were filled to when I took delivery and I haven’t had any reason to change it.

[Westside Guy]

Originally Posted by Kwajtrader

I have a 2021 M40i with 19” Pilot SS tires and the manual is the same as what you posted: 32 front/rear. That’s what mine were filled to when I took delivery and I haven’t had any reason to change it.

I think the verdict is in and I will go with 32 front/ rear.

I am still puzzled why TAZ007 had 38/40 unless it was for over 100 mph.

[TAZ007]

Originally Posted by Westside Guy

I think the verdict is in and I will go with 32 front/ rear.

I am still puzzled why TAZ007 had 38/40 unless it was for over 100 mph.

[MG 228i]

Originally Posted by Westside Guy

Can I assume you have the 19 inch Michelin Pilot Super Sports and not the 18 inch tires?

That is correct.

[Kwajtrader]

Originally Posted by TAZ007

Because they’d be at 40/42 if there were a spec for 120 and above