I was looking into a C170 with a continental, and the owner said they get around 110mph at 8-9gph.

If I weren't headed anywhere fast, is there anything wrong with prolonged flight at lower RPMs to decrease fuel flow?

I was looking at a Citabria, and it seems that according to the POH you can run it around 2000rpm to keep at at about 100mph and 5gph if you're not in a rush. What about the same thing with a Lycoming?

Thanks,

Jesse

I've got a stock 170A. I'll run the C-145 at 2250, at 3500-4500 msl and burn ~6gph. She'll give me 90-95 knots, but carb ice is even more of an issue than normal operating like that.

YMMV. (literally)

in my experience continentals run at low power settings start burning oil.

You can plan on 7.5GPH for 90% of your flying at approx 100KTS turning 2450RPM. Obviously you can pull it back and save more.

Ya I saw consistently 7.5 gph and 110 mph TAS with a climb/cruse prop. #2 cylinder likes to fail Went thru 2 of them in 550 hours.

Any issues with running a lycoming O-320 at low power settings for long periods?

jugheadF15 wrote:You can plan on 7.5GPH for 90% of your flying at approx 100KTS turning 2450RPM. Obviously you can pull it back and save more.

That was my experience with my C170 also.

We have C170B with 145hp O-300 and seaplane propeller. In normal cruise its fuel flow is a bit over 6gph, 2450rpm and 92KTS. It is possible to fly even slower, but it is quite slow then.