Most fuel efficient twin?
 

Hi all,

I currently fly a cherokee 6-300 and plan on around 60LPH fuel burn. Actual average is 54-56 but it gives a good safety margin and is easy to calculate.
My question is, what is the most fuel efficient twin, per mile flown? I am thinking of trading the cherokee in for a twin as I will be doing a fair bit of IFR in the next couple of years so am looking for something that has a decent trade-off for speed and fuel consumption.

Cheers for the help.

Surely the Tecnam P2006 must beat all the others hands down, in matters of fuel burn?

The DA-42 running on Diesel/Jet-A1 burns 42LPH. What does the Tecnam burn

Efficient twin
 

Perhaps not, I think the Twin Comanche would still come out on top or very close as it is a true 160 kt aircraft. The Tecnam is a 140kt aircraft. Add on the cost of the extra fuel to do 20 miles and the difference would be small.

The range of a Twin Com far exceeds the Tecnam so fewer stops for fuel, also the TBO on the Tecnam is only 1500 hours.

The diamond cruises at 154kts @70% power, however I don't know what a used one goes for today

The DA42 should be up there - it burns about 11 USG/hr at 140kt at low level.

I've been told the p2006 burns about 38 lts an hour


This can of course be MOGAS with 10% ethanol.

Tecnam P2006T burns 10gph full throttle and 8.8gph at economy cruise. Mogas as well. Hard to beat. If you want a cheaper to run twin you'll have to start looking at a Cri-Cri..:)

In terms of fuel cost or fuel volume?

A diesel DA42 is pretty comparable with the Tecnam in terms of nm/gal (and slightly faster), but depending on location Jet A may be cheaper pr gal than avgas.

I seem to recall that you can throttle the diesel DA42 back to some ridiculously low power setting like 40% and get 7.5gph at 120 kts, or something like that.

I really like the Tecnam btw. If only the specs weren't so much on the low side...(620 nm range, cruise 135 kts, ceiling FL150, t/o distance 450m - and a new one is still USD450k...)

Full IFR Twin Commanche with logbooks in perfect order that has been hangered with decent avionics. Watch out for cavitation in the fuel tanks but find one with tip tanks and you can fly a very long way between fuel stops. It's a lovely and very under rated machine. Try the US perhaps where some of them are respected, loved and pampered.

International Comanche Society

If you define "fuel efficiency" as "lowest fuel burn per passenger mile", then you'd probably be looking at the Boeing Dreamliner.

However, since this was posted in PF, your mission is probably not to haul 200+ persons across the oceans. So what is your mission? 4 persons? 6 persons? 8?What is your target speed, range? Budget?

Those specs are poor for a going-places supposedly IFR aircraft, costing that much money.

620nm range is not much good for European touring (for $450k) unless you live in southern Germany and want to pop over to Croatia for lunch, FL150 ceiling is no good for IFR anyway because it won't get you into VMC on top in a lot of non-frontal conditions (it's similar to an Archer), the 450m t/o distance is good though.

I absolutely don't want to start another SE v. ME thread :) but take my TB20: 1300nm range, FL200 ceiling, 450m takeoff roll, and the new cost (2002) was c. US$300k. A potential Tecnam owner doesn't need a PhD to be aware of this stuff.

Ever since Mr Thielert and Messrs Diamond have comprehensively p1ssed all over the twin engine options, I can see the Tecnam being popular with ATPL schools whose prime objective is to fly as slowly as possible (because they charge by the hour, and the punters have to pack X hours in their logbooks) consistently with going just fast enough to fly NDB holds in 30kt crosswinds without getting blown away sideways ;) , who don't care about going places, and who do everything at low levels.

But the options for a serious private pilot are rather poor, which is why I have not done anything "ME" myself. You have a choice of 1950s airframes, most of which were built in the 1960s or 70s, or the DA42 with its engines which are either dodgy or as yet unproven, and that's about it. It's a real shame because the DA42 could have been a revolution.

If you are interested in efficiency have a look at this;

Twin-R

Only of academic interest in the short term. Dyn Aero went bust a few months ago with the twin ¾ of the way through its certification. The company has been bought as a going concern and spares etc are back up and running but no word yet on the plans for the twin. The efficiency comparison charts make interesting reading though.

Tecnam are reported to be working on a Rotax 914 turbo version which should make a big difference to the aircraft.

Rod1

thanks for the feedback guys. Backpacker, I am hoping to use the plane to primarily fly between a cattle property and city roughly 400nm away. Speed wise, anything faster than 150kts would be desirable. Budget wise I am undecided, but have noticed that here (Australia), there seem to be a lot of cheaper twins coming onto the market.

What's the runway like at that cattle property? And is 100LL available there? (I assume yes, since you're doing this in a Cherokee six already, but at what cost? If you could have an aircraft that would run on regular car diesel and Jet-A, or regular car unleaded, it might make operations a lot simpler.)

And do you need basic IFR for the occasional cloud, or a serious IFR tourer, de-iced and everything?

And what's the terrain in-between? If you were to keep on flying a single and had an engine failure, what would be the chances of survival? Because to be honest, this sounds like a typical job for a C182 with an SMA diesel or something similar to that.

One of the problems with twins is the horrendous maintennce costs. You might find yourself better off sticking with what you currently fly... :suspect:

In a slightly backward country such as Australia http://images.ibsrv.net/ibsrv/res/sr...lies/wink2.gif you are also going to need to consider the ability to service the engine - there may not be that many approved diesel service agents.

As an example the DA42 has its advantages but even in Europe there are places you would not want to develop an engine fault.

"Tecnam are reported to be working on a Rotax 914 turbo version"

This aircraft could already be a bit of game changer in the IR instrcutional market place and if turbo charged and/or FIKI it might be suitabel for twin piston AOC ops.

As Peter says, the Tecnam is fairly useless for touring. A useful load of 400 kg means you'll never be able to carry 4 adults anywhere, indeed 3 with fuel will be a challenge.
140 knots is too slow for a twin IFR tourer. You may not be burning much gas but you are travelling at single engine speeds. And the range is dreadful.
Also the limiting speed for the gear is 90kts. Try flying an approach into any reasonably busy airfield at under 90 knots and I'd take a book to read while your being held.
I'm sure it's a good training aircraft for schools but for hard IFR it's just not suitable.

There are 3 sets of numbers that matter to an aircraft owner:

1) Useful load, so that you have enough capacity to carry your typical load

2) Overall performance, so that the aircraft has the range and speed appropriate for your typical trip and the runway performance necessary to operate from your typical airfield.

3) Total ownership costs. Fuel use is only one part of the equation. A rough but nevertheless surprisingly accurate predictor of costs is when comparing like performance singles and twins double the cost of the single. So for example a Seminole will be twice the total costs of an Arrow and and an Seneca 2/3 will be twice the cost of a Lance/Saratoga for the same miles flown. I would suggest that for a Cherokee six the same equation would roughly apply. Double the money for approximately the same load, range and runway performance.

The Twin Comanche is a very impressive aircraft with very good fuel efficiency and simple and economical 4 cylinder engines. However the cabin is smaller and the payload much less then a Cherokee six and parts are getting harder and more expensive to find. To equal the capability of the Cherokee Six I would say you would have to get an Aztec.