I've got two 5.0 liters in my stable - one of them an M engine (ok it's 4.94 liters). It gets 23mpg, easily, cruising at 75-80mph.
I really, really think it's possible to have a highly efficient "efficient design", more aerodynamic, lighter weight 3.0 liter engine pulling mid 20s mpg regularly.
If this thing is considered a gas guzzler, I'm gonna be ticked
