I've tried everything. My diesel gets the same MPG no matter how I drive it. 18MPG. Unless I'm towing then it goes down to about 14MPG.
Interestingly enough though my 99 4Runner's mpg increased from 16-17 to 19-20mpg just by increasing the tire diameter from 29" to 31". It had some G-ride 20" bling wheels on at and I changed back to the factory ones. It has the 4.30:1 gears though.
