4x2 seems to give best mileage around town and on short trips for me if I take it easy(17-18 mpg). The fuel saver level 1x1 does good on longer trips, if I can stand the lack of grunt. Just did a 2000+ mile round trip to Corpus, got about 19 mpg at 75-80 mph. Not the best, but "I can't drive 55".
Lon