luxury1

Is it dangerous to have the PSI levels a little above the posted amount (28 F / 30 R)? Mine are currently 32 F / 34 R.

hilmar2k

Dangerous, no. It will affect handling and tire wear more than anything else. As long as you stay below the PSI rating for the tire, you will be safe. I actually find that 1-2 PSI above the recommended handles better.

islanguam

Always take the PSI listed on the driver side door, not the max listed on the tire. My old E320 was brought in for service and they maxed the PSI as listed on the tire...the ride was awfully stiff!
Hilmar2k is right, though...I also find that 1-2 PSI above the recommended handles better.

luxury1

Is 4 too much?

hilmar2k

Too much is subjective as long as you are under the maximum PSI for the tire. Your best bet is to experiment with different combinations and decide which you feel is best. I would maintain the higher PSI in front, but you can reduce or increase the difference. But like islanguam said, don't go crazy, your ride and tire wear will suffer greatly.

SAguirre

There is no ONE PSI setting that is best for all kinds of driving. My Mercedes that I had in Germany when I lived there and my old Audi here in the US have two distinct pressure settings for the car. One is for normal driving and one is for a full car if you intend to drive at average speeds of 100MPH. Needless to say, the US market does not have the two different PSI settings posted anymore. Maybe one of our European board members can post what the recommendations are. It is interesting to see.

I personally never put the PSI that is on the door. If I do it is only when I pump the tire pressure and it is well bellow freezing outside. I find that the outside of the tires wear more when I have the normal PSI setting. On 4-Matic cars, there is a tendency to wear the outside edges of the front tires, so 4 – 8 PSI more usually eliminates this issue.

I only have 3,000 miles on the OEM tires, and I had them about 8 PSI higher than what it said on the door. The ride is a bit harder, but I really don’t mind that. Also, when I took the wheels off, the tread wear was still perfectly even. My snow tires have about 4,500 miles on them and I have them 3 PSI higher. So far the wear is perfect too.

So my advice on this is that you should experiment with it. I know that RWD Es tend to really wear out the middle tread if they are over inflated, so watch out. Also, as it has been mentioned, it will not be a problem to increase the tire pressure as long as you are still bellow the max. rating for the tire itself. Now, if you are driving a Corvair a 911, or an old VW Beatle, you might have some negative handling issues due to the design of the car. But the E is not like that, so you are in the clear.

Steve

E2233

Why does the manufacturer recommend lower tire pressure in the front tires?

nantucketsleigh

read somewhere that higher rear pressure facilitates understeer. i run 34lbs all around. don't notice any significant degradation of the ride. car feels a tiny bit livelier.