Gary is right. I carried a lot of dead weight around in the form of a spare tire mounted on a rim I polished on both sides.

Since I no longer carry a spare if I lose a tire I have 315's all around so I can limp to safety by putting the bad tire on the tag and lifting the tag. More practically I carry plugs and can fix a puncture enough to get me home. If the tire is beyond repair I get the closest size tire I can if 315's are not available and stick it on the tag. I did that once with the original coach and again with this one.

The key is fanatical attention to tire pressures.