Quote Originally Posted by skids72
If your van is pretty heavy (4000+ lbs?) you'll probably want to start with a bit more pressure maybe closer to 14-15psi then go from there... you can almost eyeball it looking at the tire where it meets the pavement... maybe about 3-4" wide contact (flat) with the ground from front to back of contact patch then adjust up or down from there...

-Chris
that's great , i'll give it a try
i'll have to weigh the van i guess for a more accurate idea

thanks for the advice