> The main reason for me going to 15s is the Michelin Agilis tires,
which are supposed to be hot stuff.<

Karl,

Unless one prefers to go to a larger sized wheel one can buy an Agilis tire
made for the Vanagon 14 inch wheel. It's the Michelin Agilis 61. They're
known as:  Michelin Agilis 61, 185 R14C TL 99R, 6 ply load range C, 1710
lbs. @ 54 psi. The Agilis 51 is sized for the Eurovan. Sweet tires!

Garrett Adams
83.5 Adventurewagen GL
Stockton, California