G-Benz is exactly right with his explanation. Highway miles are ABSOLUTELY the easiest duty your car will see. With an MB especially. These cars are designed with wide open autobahn duty in mind.

My 240D went a half million miles with probably 98% of those miles on the highway about as fast as the 67HP would let it run. Brakes, tires, engine, trans lasted incredibly long periods. The car went over a half million miles before I ever replaced any suspension components other than shocks or a u-joint or flex disk.

Again, highway miles are the easiest duty.

Enyoy your trip,