Start at the bottom of each range. Four driven wheels each, regular in the tank of each, and the Durango's 3.6L V-6 is
rated 2 mpg better in the city, 5 better on the highway and 3 better combined than the Tahoe's 5.3L V8. That is a V6
against a V8, so the Chevrolet answers with 60 more horsepower and 123 lb-ft more torque. Which half of that trade
matters depends on whether your week is mostly errands or mostly trailer.
The mid-range V8s land close. The Durango's 5.7L HEMI V-8 makes 5 more horsepower and 7 lb-ft more torque than the
Tahoe's 5.3L, 360 hp and 390 lb-ft against 355 and 383.
Move to premium fuel and the economy gap narrows to almost nothing, but the 2 engines are doing different jobs. The
Tahoe's 6.2L V8 is rated 1 mpg better in the city and 1 better combined; the Durango's 6.4L V-8 is rated 1 better on
the highway. The 6.4L also makes 475 hp against 420 hp, so it is the performance engine of the pair rather than a
like-for-like alternative.
The Tahoe also offers a 3.0L I-6 turbo-diesel, 305 hp at 3,750 rpm and 495 lb-ft at 2,750 rpm, rated 20 city / 24
highway / 22 combined with four-wheel drive. In combined driving, that is 2 mpg above the Durango's most efficient
all-wheel-drive engine, the 3.6L V-6 at 20. The 2 figures are measured on different fuels, diesel against regular, so
weigh them with the pump prices you actually pay.
What the fuel grade means at the pump: the entry engine on each side runs on regular unleaded, and that is the pump
most of these vehicles will pull up to. Because the grade matches, that difference shows up in your fuel bill rather
than only on paper: same pump, same price per gallon, 3 mpg apart in combined driving, with the Durango ahead.
Step up to the Durango's 6.4L V-8 or the Tahoe's 6.2L V8 and both call for premium, which costs more per gallon than
regular at every single fill. That is not a one-time line on the window sticker. It repeats every week you own the
vehicle, on the run up I-79 and on the errands around the valley, and it appears in no payment quote you will be shown.
The Tahoe's turbo-diesel is a third pump at a third price, so it belongs in a separate mental column rather than in a
straight comparison with either gasoline engine.
So compare the engine you would actually buy, on the fuel it actually takes. The best figure in either lineup tells you
nothing about your own fuel bill if it belongs to an engine you will never order.
One more difference worth knowing before you shop trims: the GT is the only Durango offered with rear-wheel drive.
Every other trim in the lineup drives all 4 wheels.