hi Jeff,

it's OK as long as you stick to the recommended tires on the sticker. But
as you know tires technology evolved for 25 years since the last vanagon
was built.

since my choice of tires are different from the sticker, I have my own rule
of thumb - minus 15psi from the Max for the Front and minus 10psi from the
Max for the rear...

or depending on the max 10psi from the Max for the Front and minus 5psi
from the Max for the rear...

but then this my own rule of thumb.. other opinions my vary