It’s very much on topic though (see OP). The Mazda engine is a diesel, only running on gasoline. The only real merit of a (ordinary) diesel is it can use Jet fuel. This is much better at places with no (permanent) avgas facilities, it’s also cheaper than avgas at some places. What will the merits of this Mazda diesel engine in an aircraft be, when it cannot use Jet fuel? The easy answer is none, it’s a waste of time altogether. IMO that’s way too easy an answer. The correct answer depends on the price of the engine (presumably costly), and the cost of getting fuel to places with no fuel (very cheap).
In a “Jet fuel world” a diesel engine will be beneficial. But only if you fly random at different airports, and seldom or never visits the same airport more than once. Arranging avgas will be expensive and lots of work, it will be a major hurdle. But, consider the aircraft is used in a more commercial way, then you won’t fly completely at random. It’s also natural to assume there is more than one aircraft, operating in a network of routes. You will at least have a few “bases” here and there. Then, organizing permanent AVGAS at those “bases” will cost only a small fraction of the difference between the cost of a diesel engine and a Lycoming. Thus, IMO, the apparent merit of a diesel engine does not exist in anything resembling a normal way of operating an aircraft. It’s just a pipe dream. The reason for that is the engine itself is extremely costly, and arranging fuel is cheap and simple. Tax related issues could have major effect, but that could go either way. In Norway, using mogas on aircraft, is just as cheap as using Jet fuel.
What are the real merits of this Mazda gasoline diesel used in an aircraft? Probably none still, because there is no reason a conversion will not cost exactly as much as the current diesel conversions. The fuel issue is close to irrelevant though, but worse than using Jet fuel of course. But what will happen if this (virtual as of yet) aircraft Mazda engine would cost “only” 60k running on mogas ?
LeSving wrote:
The only real merit of a (ordinary) diesel is it can use Jet fuel.
Significantly higher efficiency (read: more MPG) is completely irrelevant? Fuel is free and tank volume (endurance) is never a concern?
The HCCI cycle improves efficiency over the standard Otto cycle, bringing it closer to the Diesel cycle. Still, for aviation this engine development is not relevant, might want to look at it in 15 years from now.
LeSving wrote:
and the cost of getting fuel to places with no fuel (very cheap).
This couldn’t be further from the truth. I suggest you visit Greece and ask about AVGAS prices and availability. Then you enquire about the cost of establishing and running a fuel station at an airport in a country of your choice that meets all legal requirements. Or maybe your understanding of getting fuel to places with no fuel is to roll 2 barrels of Mogas through the security at an international airport?
An IO360 costs $30k, a CD-155 is $120k. The difference is $90k. What can you get for $90k? For one, you can ship tons and tons of avgas around the world several times for that.
The cost of a CD-155 is more like 45k… Your mistake may come from the (roughly) 120k for putting 2 of such engines on a DA42, which includes some airframe mods, which we discussed on another thread i think
The cost of a CD-155 is more like 45k
Maybe to a “high volume” OEM for a basic engine without any auxiliary stuff? The price is from Glasair and shows the actual difference all things included. The added cost of a CD-155 is 90k over an IO360, and then you also have to install it yourself.
A CD-155 retrofit kit for a C172 is 60k US give or take, including a new MTV propeller. Here
(Is that “aggressive”?)
achimha wrote:
This couldn’t be further from the truth. I suggest you visit Greece and ask about AVGAS prices and availability.
You should take a step back and look at the bigger picture. Mogas is easy to get on any smaller field just about anywhere. And yes, even with an electric pump. There is a reason why avgas isn’t readily available on larger airports anymore, but that reason is not that piston diesels are perceived a better aircraft engines than Lycomings and Continentals. For what seems to be your need (flying at random larger airports, as I said in my previous post), then a diesel piston engine may be exactly what you need though. Just don’t expect the majority of GA (including commercial GA) to agree with your problem or your (insanely costly) solution 
For the record. At ENOP we have mogas, avgas (100LL) and Jet A-1 at the pump. ENOP is a tiny private field in what you would describe as “in the middle of nowhere”. I bet the pump price is less than anywhere in continental Europe also. Liquid fuel is the cheapest and easiest commodity to ship around the world.
Back to topic. A slightly speculative explanation:
For the record – if you think liquid fuel is the cheapest and easiest commodity to ship around the world, you clearly express opinion not fact.
W regards to your “insanely costly” opinion – feel free to download the pricing pdf from Technify that will confirm the 45k EUR figure.
Opinion <> Fact.
LeSving wrote:
Mogas is easy to get on any smaller field just about anywhere.
That also is opinion, not fact.
Shorrick_Mk2 wrote:
feel free to download the pricing pdf from Technify that will confirm the 45k EUR figure
The link doesn’t work. But you can look at this link. The CD-155 is an US$ 88.995,- option to replace the stock IO-360.
Shorrick_Mk2 wrote:
For the record – if you think liquid fuel is the cheapest and easiest commodity to ship around the world, you clearly express opinion not fact.
It’s pure logic. If it wasn’t all other shipping and most of industry would grind to a halt. Cobalt wrote:
That also is opinion, not fact.
Sorry for not being a living fact book Jesus ….
You’re just trolling the forum LeSving…
The fact how cheap and easy it is to drive around the Norwegian countryside with a barrel of Mogas loaded on your tractor doesn’t really help me to convince the airport I want to visit to stock it for my consumption. Never had it, never will have it. So completely besides the point.
PS: Even the mighty US armed forces think that it is advantageous to install diesel engines in their smaller aircraft than messing around with a minority fuel.
