RV-7A vrs C150 Efficiency

David-aviator · #1 09-09-2011, 09:29 AM

Yesterday I flew a trip that consumed 3.9 gallons of fuel logging .8 on the Hobbs.

Just for kicks, I simulated that trip in a C150 using performance numbers from its FHB.

Both trips were at 6 GPH power setting after take off. The RV made the trip in .8, the Cessna would have taken 1.0. (127KTAS vrs 103KTAS)

The RV-7A with its 180 HP engine is 18% more efficient than the C150 with its 100HP 0200.

Flying the RV is a good deal anyway you measure it.

DEWATSON · #2 09-09-2011, 10:11 AM

RV8
IO360 ECI TITAN engine 192 horsepower
Hartzell constant speed propeller

30.6 flight hours
241.95 gallons of 100LL
4839.9 statute miles
averaged 138 knots including climbs and taxiis
averaged 20.0036 statute miles per gallon
averaged 7.9 gallons per hour

Most of the flight was done at 2350 RPM with about 19.5 inches of manifold pressure. I didn't want to leave the airplane that was flying along with me.

rocketbob · #3 09-09-2011, 10:58 AM

Since I am RV/Rocketless at the moment, I had to fly my C150 to OSH.

You know no pain until you have to fly X/C in a slow airplane.

I burned almost 50% more gas to get up there and back in the 150 than I did in the RV. Your 18% figure is off by a fair amount since most tired old C150s don't make anything close to book numbers.

JDRhodes · #4 09-09-2011, 11:18 AM

I agree with Bob - Don't think I've ever flown a C-150 that would cruise anywhere close 103kts! Try 90kts.

JDRhodes · #5 09-09-2011, 01:11 PM

I wonder ? You?ve demonstrated that the RV is very efficient at cross country cruising, assuming you have the self control to pull the power back to very low fuel flows (45%? Or less?). But I wonder which is most efficient for the mission of learning to fly? Take offs and landings, local area maneuvering, short cross countries. Each airplane has its mission. The C150 is pretty far out of its element as a long distance cruiser.