Thanks for the advice. I have a 2007 Mercury Mariner Hybrid with AWD with 16,000 miles on it. Last week in the first 17 miles of driving around town on mostly flat side streets (with a couple of hills) I managed 52.2 mpg (next time I'm going to video tape it) without really being a nusiance. I'm getting about 33-37 in combination city/hwy. I keep to the speed limits or slightly below and never in the fast lane on I-15, Ogden to Murray, Utah. Oddly enough I can get 31 with my Volvo Cross-couuntry in city/hwy combo in the same trip.