stock 45-series tires on the e320 indicates 32 psi front and 36 psi for rear. if i change it to 35-series and 30-series should the psi remain the same? i've heard mixed input from different people. the shop that installed my new tires say 40 psi all around. dealer say stay with the same 32/36 psi.
thanks.

 

Run them at 32F/36R. If you don't like the ride quality you can raise or lower the pressure but be sure to keep the 4 lb. difference between the front and rear tires.

 

doesn't the series matter for the tire pressure? I would think that the 30 series would require higher pressure because of the thinner sidewall.

 

provided the lower profile tire is properly sized by the tire shop, there is no need to change the pressure. My '08is factory equipped with 245/40's up front and 265/35's in back. The door tag calls for 28F/32R.

 

35's and 30's did you put on 19 or 20 inch rims?You are going to ruin your ride quality, make it nearly impossible without spending big bucks to get it properly aligned(you did get it aligned didn't you?)
Your ride will be harsh, your tire life will be nil.Please say it ain't so!!!!!
ohlord