It takes more fuel to get up there, though.
I knew that one was coming!
That's true, so it's not efficient for a short flight, but we're talking about
cross-country! You make up the difference in higher altitude economy and a long reduced-power descent, if the flight is long enough! I can routinely make 3.5 hour flights in a 150 or 152 with standard tanks, cover nearly 400 miles, and land with plenty of reserve in the tanks, flying at 7,500' or higher! I've done it several times!
