31 City / 42 Highway / 35 Combined
$56,485

Jaguar's large and lovely XF isn't usually known for its efficiency – unless we're talking about the 35 mile-per-gallon combined diesel model. The turbocharged 2.0-liter engine produces 180 horsepower (134 kilowatts) and helps return 31 miles per gallon in the city and 42 on the highway. Annual fuel costs are a bit higher at $1,300, due in part to the price of diesel.