It depends on which places charge massive taxes on Jet A1 for private aviation to artificially make it as expensive as Avgas so that GA is not getting to profit from it. I believe that is what the UK does.
Of course the current Diesels also have a much better consumption, so they still have an efficiency advantage over a similar Avgas engine even if the price is artificially lifted up to Avgas levels.
If you compare the direct fuel cost of a 155 hp Centurion 2 to a O320, the difference is striking even today.
The O320 uses 9 GPH @ 75%, 7.4 GPH at 65%. With current prices in LSZF (Birrfeld) this means €73 / €60 per hour.
The Centurion uses 5.8 GPH at max power down to 4.7 GPH at Economy. With current prices this means €41 / €32 per hour.
Folks, that is a saving of 45-47% in fuel alone with an engine whose power curve is significantly better than the O320 and at altitude will outdo the O360.
At 100 hrs per year (typical private plane usage) this means a saving of a whopping 3000€ per year or over a TBO of 1600 hrs 47 k €, just in fuel cost.
Worth considering? I think so.
…over a TBO of 1600 hrs 47 k €, just in fuel cost.
But unfortunately the Thielert engine does not have this kind of TBO. Instead it has a TBR (with R standing for replacement, no overhaul possible) of only 1200 hours. Unless they can increase that figure or allow overhauls, fiancially the old AVGAS engine still has the advantage.
But unfortunately the Thielert engine does not have this kind of TBO. Instead it has a TBR (with R standing for replacement, no overhaul possible) of only 1200 hours. Unless they can increase that figure or allow overhauls, fiancially the old AVGAS engine still has the advantage.
And we come to issue from another thread – price of overhaul compared to price of new engine. 47k€ should be enough for new Thielert engine and 1200 hours will soon be extended to 1500. I guess further development will bring something more.
Even with TBR, if you save say 40k EUR over the TBR duration you’re still the cost of an overhaul ahead of the “tried and true” O-320 design.
That might become the most successful aero diesel. The Centurion 4.0 was certified ages ago and is a good engine but it never saw any shipments and is dead now because the underlying Mercedes V8 diesel has been discontinued. Also you no longer need 8 cylinders for this power and it’s smarter to use a V6.
That engine might fit well in a TB20 and a 182 RG… 
That engine might fit well in a TB20 and a 182 RG…
Isn’t it to heavy?
Isn’t it to heavy?
Plenty of space in the elevator for lead I believe the Deltahawk should be comparable, the SR20 Conti is lighter than the ultra heavy TB20 engine.
It depends on which places charge massive taxes on Jet A1 for private aviation to artificially make it as expensive as Avgas so that GA is not getting to profit from it. I believe that is what the UK does.
Tax issues do warp people’s behavior in unpredictable and generally inefficient ways, but I think in this case it’s outrageous European gasoline taxes that are the issue.
Minus the tax advantage I think the sole rational reason for a diesel is fuel availability in geographic areas where GA has yet to develop. The high altitude performance is attractive too, but the supercharger that creates it isn’t attractive. If it was, more aircraft would have superchargers already, regardless of engine type. The cost, weight and complexity have only made sense to a small segment of buyers.
It’ll be interesting to see where the volume for diesel aero engines stabilizes in say 30 years. None if them are in volume production for new aircraft now, Thielert lost its two main customers (US Army and Diamond), Austro is the closest with one customer that’s shipping a few, and the others have yet to be shipped on a new airframe.
Or maybe do what the tractor pulling guys have been doing for donkeys years, two stage turbo charging.
