Ok , i am sure somebody touched this maybe, but i still would like to know,my cluster says when on and in parking 504 miles range, yet i can barely drive 300 miles on full tank,i know about city and hwy but, it is a little low, dont you think? 2005 SL500

 

My 2007 SL550's instrument cluster is pretty generous when it reports the car's capabilities. When I calculate miles/gallon, it is almost always 2 miles/gallon less than what the dash computer calculates. But the real full tank range (21.1 gallon tank) is typically 450 miles (versus the 515 miles displayed at fill-up).