Donnymac

First off. I am new to the MB world but very impressed with my "new to me" 2012 S550.

TPS issue?

Made my second long drive and figured out how to display TPsi. Panel read both R at 31 and both L at 34. Sun was not an issue. Pavement was fine. Unfortunately had no manual gages with me during the drive.

This morning, all 4 tires manual gaged at 29psi cold(confirmed by two different brand race gages). Tires are in good shape, are Cont and car has 21k miles.

Door jamb says 39psi cold. Did that. Getting back on HWY soon. Will report back.

Thoughts?

ImInPA

Sounds normal to me. Especially when you consider the excess heat generated by driving with tires so underinflated. 10 lbs low is VERY low!

Donnymac

Agree. At 39 cold, psi ranged 41-43 on the hwy. TPS appears to be fine at proper inflation. All is well. Thanks for the input.

Wheel option psi question. Door jamb recommends 39si cold - assuming 18" wheel. As wheels are 19 as ordered or if they were 20s, would recommended cold psi still be 39? Or?

Thanks.