For some reason I'm locked out of the wheels and tires section so I'll post here. My door tag on my my 07 MCS says 38psi cold for all four tires. Is that the optimum pressure, or is there a better setting for ride quality and tread life? I'm currently running a set of new Conti Extreme Contact DWS 205/45/17 standard tires(non run flats). When I picked my car up from from having them installed I checked the pressures a few days later only to find all four tires set to the max cold pressure of 51 psi. I immediately dropped them down to 42 in the front and 40 in the rear. The car feels a lot better now. I'm relying on the experience you all have had with tire pressures on these cars. Thank you.
I have the exact same car and for street driving I follow the recommended pressure of 38psi and get pretty even wear
I believe the air pressure specified on the door is for the original run-flat tires. Since you have changed to non-original equipment tires, you will need to select your own air pressure. I usually run 2 psi less in the rear compared to the front. I am currently using 38/36 for the street with 215/40 tires. Your 42/40 is probably OK with 45 series tires since your have more sidewall for ride comfort. If your ride is a little to stiff you can lower the pressure a couple psi. The trade-off is the higher pressure will provide better fuel economy.
Anywhere from 33-40 psi is good. Lower is more comfortable, higher is better fuel economy. 36 is a good compromise.
Michelin 215/45/17's here I have found thet 35psi all around seems to work well on my 2009 JCW with sport suspension. Michelin Exalta PE2's and I just rotated them same side at 5,000 miles with no sign of uneven wear at all. I called Michelin and they said anything from 33psi to 38psi would be a good choice to use. Under 33psi would probably cause under inflation problems. 35psi is what I'll stick with. Good ride and handling and no tire noise at all.
Thank you. I'll try 38 front and 36 rear and see how that feels and go from there. My brain is telling me I'll probably end up at 40 front and 38 rear.
I have Star Specs on and run them at 32psi. When they were first put on the shop put them at 40 :eek6: Waaaaay too much for my taste.
I run 35F 34R on my Continental Extremecontact DW's - 215/45/17 - works very well car - Dragon tested and approved.