Jay,
WOW !!
Where did all this theory come from?
I drive my van hard.
And I take tollway ramps like it was my BMW, ( try to anyway) and
experience none of the mentioned phenomena.
I have 35 psi in my bags, and 35 is 35 is 35.
I suppose at a 10g cornering load something like you mentioned might
occur, but I highly doubt that you could ever hit a corner hard enough
in your Vanagon ( without rolling it over) to experience the problem you
mentioned.

Later,

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Terry 85 GL