I never did do anything formal. I guess I've just flown the plane enough now and am generally conservative enough with respect to fuel that it's not an issue. And don't let anyone tell you that the mixture in a Luscombe doesn't do anything. With the Stromberg, it auto leans up to 5,000 feet, but at higher altitudes, say around 10,000, I'll run full lean and gain about 40 RPM and save over a gallon per hour. I mention it in a few of my videos. I did, however, run a tank dry on purpose earlier on for testing to figure out about how long I could go. That was without leaning, though, but it gave me a good minimum I'd be able to go, and I always run a timer while I'm flying. Way before my tanks run dry, I want to be out of the plane. Any anyway, I like visiting new airports, so I land pretty frequently.