Fuel Usage

My Coupe did the same . . . . 6 to 7 GPH at cruise. I had my shop adjust carb and INSTALL A LONG PULL MIXTURE CABLE THAT ALLOWS REAL LEANING CAPABILITY. This change will not allow engine shut down, still use key switch. At 75% I lean to 5.5 GPH with normal CHT and EGT.

TruTach11, 1 RPM resolution. A/C Spruce has them for $ 194. Best money that I have spent on it.

Thought about getting one. What kind do you have,
how much are they, and where did you get it?
Thanks, Bruce.

Wish you both had digital optical tachs. I have used them on my Alon and Cessna 150 for years. Priceless engine info. The rag wings were cleaner than metalised.

Some Ercoupes are aerodynamically clean, some dirty.
With tach error and pitch differences thrown in, ground
speed is irrelevant. What matters is how much fuel is
required to turn the engine for an hour at somewhat the
same rpm. A gallon or so difference is not worth much of
a discussion. Assuming both of our engines are turning
in the vicinity of 2100, the fuel usage difference between
his and mine is of interest, for discussion. -Bruce.

Bruce, Donald, what are your GPS ground speeds? Tachs are not accurate on older planes. Prop pitch may vary. If you are both getting the same ground speed with the different fuel flows, that would be something to look at. My C-75 415C burned about 5.5-6 GPH. My Alon about 6-6.5, but at a ground speed of 109 MPH.