Hey, not so fast -- I want to disagree that the wider tire is automatically
better traction.  The narrow tire concentrates the weight of the van over a
smaller area, making it less prone to hydroplane in wet conditions and less
likely to 'toboggan' over the snow.  They dig in.  On dry pavement, or in
loose dirt and sand, the wider may be better.  All the guys I used to know
who had wide tires on their Camaros used to swap them for  narrower snow
tires in the winter.

Think back to physics class.  The harder you push down, the more force it
takes to overcome friction.  More force per square inch.

Bill Marshall
85 GL Tiico "Pandora's Box"
Aurora, IL