BEST Cruise Performance RV-10

Best I've seen in the two -10s I'm familiar with is 21" mp, 2100 rpm and 12 gals/hour at 160 knots.
Bumped up to 24 squared gives more speed at a greater fuel flow
Compared to a C-182 it's same fuel flow and 40 kts. Faster for instance

Mine

Assuming you have the IO-540 with standard compression, running 100LL fuel...

My cruise setting at altitude (>8500 ft) is wide open throttle, 2360 rpm. At lower altitudes I run 23x2360. When properly operated lean of peak I get 170 ktas at 10.5 gph. If you aren't familiar with LOP, I can run rich of peak at about 12.5 gph, a little faster but not much. But I never do.

My$0.02

Altitude is a big factor here, you have not mentioned how high you are flying at.

Here is a shot of our 10, flying at 13,500'------wide open throttle, fuel 9.5 gph, 2300 rpm. Ground speed was 212 mph with a bit of a tailwind.

I usually fly at 075 or 085

Do we have 100LL in Brazil? I don't think so... Our "blue" avgas is 100/130... so I heard.

O use AvGas 100

Best cruise Performance in -10

Carlos;
I have my injectors matched to within .3 from richest to leanest, I always fly, no matter what altitude at 10GPH avg and 158KTS TAS. I have a Dynon Skyview that tells me I get about 16NM per Gallon. I know one -10 that cruises at 22MP/2100RPM, my engine does not like this configuration at all, but does at 2300 and above. Unless you have a very nice LOP spread you'll find that you will need to find your engines happy spot. If you run ROP you will get better speed but also about 12-14GPH.In the end, fly the plane at 2200, than 2300, than 2400, lean out to roughness and see where you can get to be your smoothest RPM and MAP setup.

What I have found repeatedly is that even though LOP shows a lower GPH, after stabilization, the MPG is about the same as ROP which is faster, smoother, and cooler for the lower cowl/firewall area. The engine runs okay at LOP, but much sweeter at ROP.

Maybe I'll explore again if/when the "few weeks away" 6 banger Pmag emerges, but I don't bother with LOP anymore.

After 5 yrs of flying
ROP 9000ft 2350 rpm, WOT 12.5 GPH 171kts TAS (depending on how loaded)
LOP 9000ft 2400 rpm, WOT 10.8GPH 164KTS TAS

Never have I seen over 160kts TAS LOP under 10GPH once settled in and no wind

I find these to be very consistent with other people
standard engine. I have an Aero Sport built engine
Stock Van setup

Geoff

For fastest cruise, you will be at around 8,000 ft. WOT & 2,400-2,500 rpm. ROP at 15-16gph will likely yield about 177ktas. The numbers others have is for the economy cruise that I usually fly at also.

166KTS TAS at 10,000FT burning 10.6 GPH


168kts TAS at 8500ft @ 11.9GPH


I usually flight plan for 165kts @ 12 GPH and usually use a lot less fuel.

Rob Hickman
RV-10 N402RH

Interesting.....

Well, I should be doing something productive, but this question got me diving into excel spreadsheets and summarizing the reams of data that the G3X produces each flight. Of all the great things about the modern EFIS, the data logs may be the best for quantitative geeks like me. Here are the summary statistics for three flights I worked up this evening. The first is a four way run at 8000 feet to establish maximum cruise (one interpretation of "best cruise"). The next two are "real world" economy cruise configurations (my personal interpretation of best cruise) - one a return trip from Montana, the other a recent flight returning home from Florida. These are averages for a random 30 minute sample of cruise data, one per second observations, burps and all, no cherry picking.



Note that the TAS for the max cruise test isn't really TAS, it is calculated from GPS ground speed and ground track as per the National Test Pilot School protocol, calculations are shown in the spreadsheet link below. I found that the TAS as calculated by the G3X was one knot less, which is good verification for the TAS numbers shown in the 2nd and 3rd runs. Fuel flows are also good, based on cross checks of the totalizer with amount to fill the tanks.

Here are links to the data files:
max cruise: https://dl.dropboxusercontent.com/u/95254707/July test run.xlsx
Economy Cruise 1: https://dl.dropboxusercontent.com/u/95254707/Aug test run.xlsx
Economy Cruise 2: https://dl.dropboxusercontent.com/u/95254707/Jan test run.xlsx

I am curious as to the effects of density altitude and weight (we are light) on the relationship between fuel flow and TAS. Sounds like a great multiple regression model. I am teaching a statistics course this semester, what do you think my students will be doing for their homework?

Fast

We just came in from the Bahamas on Thursday and left Ft. Pierce with full fuel and a loaded baggage compartment (to the roof) and four average adults, around 335 lbs per couple. At 8500', we trued 200 mph at full throttle and 2400 rpm. After an hour's fuel burn, we were truing 203-204...ROP burning 15.3 GPH...we were happy campers.

I dialed in 1,000 FPM on the TruTrak Vizion and it just sailed up there at 140-150 mph indicated.

Best,

Ive been flying almost 3 years exclusively LOP tight wad flying. With gas cheaper, i experimented with ROP settings and was pleasantly surprised. At 2500 rpm, i think i got up to 177 tas. I am sure i could go faster with a more aft CG maybe with some extra weight in he back.

however, the biggest surprise was how much smoother the engine ran. wow. it was noticeably smoother. i might have to let my tight wad ways go just for the smoothness.

i might have to let my tight wad ways go just for the smoothness.

Click to expand...

Wrong approach.

Get your F/A ratio's sorted, have good magneto's wires and plugs.

I can hardly tell the difference from ROP to LOP. And I should know what I am looking for