What is the fuel savings of an airliner cruising at 40000 feet leaving Denver on a 1000 mile leg vs an airport at sea level?

Very little. Denver is at 5,000 feet altitude. From sea level a loaded airliner like the B767 initially climbs about 2500 fpm. While gaining the takeoff speed from Denver uses more fuel. So there is a two minute difference in a two hour flight at most.

There can't be much fuel savings, and the fuel at Denver might be more expensive.

First answer by Eric M Jones. Last edit by Eric M Jones. Contributor trust: 506 [recommend contributor]. Question popularity: 3 [recommend question]