Meriting special mention is the forthcoming Q7 3.0 TDI, which has evaded U.S. showrooms since its launch last year. Its 3-liter turbocharged direct-injection diesel engine produces 221 horsepower and 406 foot-pounds of torque, while returning 25 mpg on the highway and a 600-miles-plus cruising range. And, unlike those smoky diesel engines from the olden days, Audi’s TDI V-6 employs direct fuel injection and a highly advanced multistage exhaust system to promote complete combustion and scrub engine emissions of particulate matter and toxic nitrogen oxides. Tailpipe gasses are laundered well enough to meet emissions standards in all 50 states—even squeaky-clean California.
Pros: A fuel-sipping diesel engine with a ton of torque.
Cons: Porsche’s Cayenne offers more power and cachet.
