The (original) tire pressure sticker in the trunk of my Euro 230SL specifies that the tire pressures are to be 1.8 atü front, and 2.2 atü rear. That converts to 26.1 psi front and 31.9 psi rear. Is that really correct, with today's tires? I assume the car handles best with those pressures, but I worry a bit about putting too much strain on the sidewalls with that low a pressure in front.
Incidentally, I just had occasion to mount the spare for the first time, and discovered that the lug bolts from my alloy wheels were too long for the steel spare wheel. Luckily, this happened in my garage, and I was able to get the shorter bolts easily, but if you have alloys and a steel spare, you might want to check the lug bolts.
Chris Earnest