lifting will have little effect if it does not change the airflow underneath. The bottom of the van is so aerodynamically "dirty". If the van had a very low front chin dam then it might have some effect. My experience with gravity racers that have clean underbodies showed that low is not necessarily better, if low is below 4 inches. When low you get a squish of airflow creating drag. 

Restating, in a vanagon, all things being equal and with no proper front dam, raising would have no effect on drag.

alistair

On 2011-12-06, at 7:08 PM, John Reynolds wrote:

> Also, it has been observed lowers fuel ecomony of cars.  Perhaps less air flow under the vechicle, perhaps less frontal area.   I wonder how lifting a van 1.5 to 2" affects fuel economy.  
>  
> While I love the idea of a ready for rough road vanagon - you have to wonder if a slightly lowered van with front air dam is really the van to go for a long. long road trip. 
>  
> John
>