In 07 the SL550 had EPA ratings of 14 city and 22 highway. These numbers resulted in a gas guzzler tax of $1700. I'm starting to wonder what car did they actually test. In daily driving, I'm getting 20-21mpg with mix of highway, country roads, and city driving. I finally went on long 400 mile highway trip and averaged 25mpg while averaging 80mph. I would think under EPA testing standards that 27-29mpg would be likely. What gives?