Ive read the engine performance graph and agree with the 15 gph at 24 squared. Not so sure about the 12 gph at 22 squared in straight and level flight.

Am very interested in others experience in flying a little slower to save gas. Also Ive heard from some "old schoolers" that I am lugging the engine at 22 squared cruise. Would also appreciate any thoughts on that issue.

Am very interested in what other owners do to save gas and extend engine life. My aircraft has an engine with 2100 hours on it with strong compression all around. Want to keep it that way as long as I can! Any thoughts on this issue would be much appreciated.

Lindbergh's practice during WWII to extend (P-38) range was to reduce RPM to lowest book value and maintain max MP for altitude. Reference to your 250 chart will show those values and fuel consumption. While I didn't know Lindbergh personally I once lived down the street from his wife in CT.

I've found the "Power Setting Table" page 48 of my POH to be pretty close to what I see in flight.

I usually cruise between 8k-12k feet and run the engine at wide open throttle. I try to stay 125 degrees ROP. At 12k feet I get about 12 GPH; at 8k feet 15 GPH. I bought a plane to save time and go fast. At these altitudes I'm only getting about 18-20 inches of MP. If you are low 24 suared is probably a good idea.

Just my thoughts,

Thanks Mark

For efficiency I would run wide open throttle at 7,500 feet or higher and reduce RPM to whatever level feels comfortable. Nothing wrong at all with 22 hundred or even less. Lean to roughness, enrich till smooth and see how it goes. Different airplanes seem to to have different "sweet spots" for RPM, find whatever works best for yours.

Jay

Haven't been on the site for a long time but saw this and had to reply. I've been charged with a '64-250 normally aspirated and see 10.5 - 11.5/GPH running between 6 - 10K altitude in the 2300rpm and 19 - 21"mp range. I usually indicate 140 - 145Kts. About 50 - 75 ROP with ~300 CHT. This is on a factory reman with about 350 - 400 hours on it, 3 blade Mac prop.