Gas MPG ??

[Jaypratt]

RV Pilots,

Question, What kind of MPG are you getting?
I have just short of 2000 RV hours and until recently have not tried to get an accurate MPG for my RV trips. I have not cared much until now about this. $5 + per gallon

This OSH 2008 trip, I saved the gas receipts and have the time but not the accurate mileage, I dodged WX etc.

Straight line miles was 1701 NM
add some WX zig zags 100??? NM
100 LL used 107.23
Divide 1800 NM by 107= 16.822 MPH?

I thought RVs got better mileage? I was low, 1500ft, some of the flight. 8500ft some of the time. Dodging WX and off course some too. so mileage is not possible to get accurate.

What or how, do you guys figure MPG.

Thanks

[Kahuna]

Hashed out here on the forum before.

[Kyle Boatright]

I departed OShkosh on Tuesday with full tanks (38 gallons, minus a little bit). After clearing the airspace at Osh, I climbed directly to 11,500' and set course for VPC, which is just NW of Atlanta. I stayed at that altitude until roughly Chattanooga, TN, where weather forced me lower.

The total distance coverd was about 620 nautical miles. Fuel consumption was 29 gallons based on full tanks at engine start and 9 gallons remaining when I arrived home (I defueled the airplane to get an accurate quantity remaining.). From engine start to shutdown was right at 4 hours.

So, my fuel burn was 7.25 GPH. My block speed (engine start to shut-down) was 155 knots. And fuel mileage was 21.4 nautical miles per gallon or 24.6 statute miles per gallon.

I have a 160 hp RV-6 with a cruise pitched Aymar Demuth prop. My cruise setting was just under 2400 rpm and just over 19" of MP. Both the power charts from Lycoming and the fuel burn indicate that this was around 60% power at 11,500'.

[AlexPeterson]

I've made the trip from Minneapolis to Fort Myers, Florida 6 or 7 times. I typically use 120 gallons +/- 5 for the round trip. It is about 1250 n.m. each way, so this breaks down to about 21 miles per n.m. or 24 mpg statute. I fly at around 22", 2300 rpm, around 7.2 gph. This give me at tas of about 156 to 160 knots. During cruise, I get about 22 miles per n.m., and on the long trips the take offs and descents seem to not affect it much.

[John Clark]

Originally Posted by Jaypratt

Straight line miles was 1701 NM
add some WX zig zags 100??? NM
100 LL used 107.23
Divide 1800 NM by 107= 16.822 MPH?

Remember to convert to statute if you want to compare the numbers to an automotive reference. 16.8 = 19.4 MPG.

John Clark
RV8 N18U "Sunshine"
KSBA

[CE196]

Originally Posted by AlexPeterson

I've made the trip from Minneapolis to Fort Myers, Florida 6 or 7 times. I typically use 120 gallons +/- 5 for the round trip. It is about 1250 n.m. each way, so this breaks down to about 21 miles per n.m. or 24 mpg statute. I fly at around 22", 2300 rpm, around 7.2 gph. This give me at tas of about 156 to 160 knots. During cruise, I get about 22 miles per n.m., and on the long trips the take offs and descents seem to not affect it much.

Is that all the faster these things are? I thought the 8, I'm building was faster than that, like at least 180 kts. My 450hp Cessna 195 cruises at 157 kts TAS while burning 22 gph. ****, what have I done!

At least my mpg between the two will more than double, maybe even triple, last check the big motor 195 was around 7 mpg. Sure is fun,,,,,till you pull up to the pump! Another plus of the Gaaaasss hog. Good shade under the wing, sitting in a chair. Where do you sit when at the RV?

Oh well, never met an airplane I did'nt like. Some of them you just don't want your friends seeing you in........Like some other nameless things.

[N941WR]

My 135 HP -9 with a climb prop works out to run 20.9 MPH.

The MPG can go up if you use the miles that you would drive, if you took your car.

What was I thinking? My original post was in error, way in error.

My total distance driven (both ways) would have been 2176 miles according to MapQuest and my total fuel burn was 96 gallons, giving me 22.6 MPG. Still a lot better than my truck but not as good as my car but still not the 40 some MPG's I was dreaming of.

[RV8iator]

You got me to wondering about the costs associated with my trip to OSH.

I steered clear of the Class B around ORD the flight up and back was 564 NM each way. (564NMx1.15=648SM)x2=1296SM round trip.
Google maps shows the fastest way to drive up and back of 881sm each way, or 1762sm round trip.
I have a VW diesel Jetta and at the speeds I drive I get 43 MPG on the highway. That works out to about 20.4 gallons of Diesel each way or 40.8 @ $4.79/gal which is $195.43. Then plan on about 15 hours in the car each way, probably a hotel each way and meals and snacks. So 200 for fuel, 200 for hotels, 50 for meals and 30 hours on the road. About 450 bucks round trip.

OR

3:25 in the RV8 going up (low altitude for winds, 4500MSL) with a burn of 32 gal. @ 4.90 ($156.80)and 3:10 on the way back (11,500 for winds and economy) with a burn of 29 @ 5.12, ($148.48)no meals, no hotels, no hassle and lots of fun is $305.28.

The way I figure it, I got 18.49 NM (21.26SM) per gal. in the plane and saved 24 hours driving time over the VW. Granted I did use 20.2 gallons more 100LL than I would have used Diesel.

As stated in a couple other post about camping and visiting and being at OSH..

Priceless!

[osxuser]

RV's are good, but come on guys, the laws of aerodynamics and stuff still apply. You get better fuel burn than the Cessna 210 I came back in... but not per seat. If you really want efficient, you could get a VeryEZ... but that has it's own set of limitations.

And to the guy building a -8 that doesn't know how fast it goes... what are you doing dude? Keep the 195 , much higher cool factor.... at similar speeds.

[frankh]

Originally Posted by CE196

Is that all the faster these things are? I thought the 8, I'm building was faster than that, like at least 180 kts. My 450hp Cessna 195 cruises at 157 kts TAS while burning 22 gph. ****, what have I done!

At least my mpg between the two will more than double, maybe even triple, last check the big motor 195 was around 7 mpg. Sure is fun,,,,,till you pull up to the pump! Another plus of the Gaaaasss hog. Good shade under the wing, sitting in a chair. Where do you sit when at the RV?

Oh well, never met an airplane I did'nt like. Some of them you just don't want your friends seeing you in........Like some other nameless things.

Yes it will do 180kts..no problem...You just won't do it at 7.2 GPH thats all..

Frank