I run at 130mph on 35 inch tires and 15 gph fuel burn. 120 at 12.8 gph. M7-235 IO-540 and MT 2 blade prop. I am 10 mph faster on 31 inch tires at high power settings- less of a difference at low power settings.

Guessing your airframe is pretty tight and clean on the outside? I know I loose a lot of airspeed from my doors being poorly fitted (read worn out). I also suspect if I put some fairings back on etc I would gain a reasonable amount of airspeed back.

Andy Young wrote:

Undaunted wrote:M7-235C on 31" cruise at 118 kts

118 knots, not mph!?

That’s quite impressive on 31â€￾s! What are your power settings at that speed?

24 squared. Burning 12.6 gph

With 850s usually 130kts same power setting.
Trading fuel for speed when traveling.
It is VERY sensitive to trim. Takes a little bit to get it trimmed perfect but is definitely reflected with speed.

Undaunted wrote:

Andy Young wrote:

Undaunted wrote:M7-235C on 31" cruise at 118 kts

118 knots, not mph!?

That’s quite impressive on 31â€￾s! What are your power settings at that speed?

24 squared. Burning 12.6 gph

With 850s usually 130kts same power setting.
Trading fuel for speed when traveling.
It is VERY sensitive to trim. Takes a little bit to get it trimmed perfect but is definitely reflected with speed.

Ah, I see. 24 squared vs. my 22 squared.

M7-260C, 31" bushwheels, babybush tailwheel, 24", 2400-2450 RPM, 13.1 GPH, 118-120 knots true up to about 3000ft, might get 3-4 knots more 5000-7000ft.

beaver wrote:M7-260C, 31" bushwheels, babybush tailwheel, 24", 2400-2450 RPM, 13.1 GPH, 118-120 knots true up to about 3000ft, might get 3-4 knots more 5000-7000ft.

That's pretty good. It looks like the spring gear models are quite a bit faster just don't think I could do it.

Oh right; spring gear. I missed that it was aâ€￾Câ€￾.