When buying tires try for the lower rolling resistant variety. Probably not too much difference on many cars. Yet with so little power everything counts. They ride a little harder and the tread may or may not last a little longer. I suspect longer though. Amount of inflation is another factor.

Tires & Fuel Economy
 

I buy by the outer diameter, most folks look for smaller, I always go for the largest diameter I can find to reduce engine RPM @ speed .

I also take the time to experiment with the best tire pressure, it's always higher than most run .

Thought on #1 bearing problem,cyl.1 runs hotter than the others,so said Mercedes.
Extra clearance was given to that cyl. How long did it take to find.
Tight running piston,could effect bearings.
Have been told by Factory reps.takes 100,000 complaints before any thing other than safety will be looked into.