Originally Posted by
FougaMagister
As for leaning the mixture, it's always highly recommended (certainly on longish trips), but there isn't much point doing it up to 3,000 ft or so; you won't get a significantly lower burn.
While that 'might' be true in a PA-28 (which after all is what this thread is about), it certainly isn't true in other aircraft. At 70% power and 1000 ft, I burn 21 gph full rich and 14.5 gph leaned. That percentage difference on a 3 hour flight in a PA-28 is the difference between arriving with 1:30 of reserves and being a glider!