 I bought this car after having driven its larger, S-class, cousin in Europe.  I rented one for a week and, after a week of driving in the mountains and highways of northern Italy was amazed at how few liters of fuel went into the tank before returning it.  Impressed, I bought an E-class shortly after my return.  I have not been disappointed.  It's performance is nothing short of phenomenal both in 0-60 terms and when passing at highway speeds.  Better yet it consistently delivers 37-38mpg on trips and in the high 20's around town.  Coupled with its comfort and handling, it's clearly the best car I've ever owned.  My only complaint is that the HVAC controls are needlessly complex.  