My XG300L is rated for 19/26. I get 16/23. My wife grabs the car if I leave it sitting--she likes it so much better than her Saturn--and that means lots of start/stop driving in town. If she's driving the car exclusively, it gets 15 MPG. My 454 Chevy got better mileage. The extra gas apparently goes to keeping the car running smooth, running the alternator (practically full-bore 130 Amps all the time) for all the electrical gizmo's, and cranking the A/C compressor.