[pjbgravely]

A few years ago I did a mod to keep dirt and salt from getting kicked up on top of my gas tank from the rear wheels. I wondered why they left this open at the factory. I found out, I lost 5 MPG closing off the rear fender wheels at the back. The pumping action of the tires makes the fender wells a high pressure area.

When I put in my rear bumper mod (mine has to cover the gas tank) I left a tunnel on both sides to let the wheel wells vent. I saw a slight increase, and dirt doesn't pile up on the gas tank.

This summer I will try to dial in the rear angle by raising or lowering the rear springs.