Yes indeed. I reckon that, the smaller the craft, the more important the power/weight ratio. Go heavier and you can better afford to aim at better efficiency, and invest a bit of weight there. “Economy of scale” is the name of that game, ISTR? It is why they make ships so big.
The biggest advantage of the Rotax is it’s ability to run without leaded fuels, not in fuel savings, I think.
…which all Lyco / Conti engines in the same power range can do just the same…
Also 91UL is not significantly cheaper than 100LL, in the UK at least.
Avoiding the lead deposits is good though.
Peter wrote:
Also 91UL is not significantly cheaper than 100LL, in the UK at least.
In Sweden it is 10% cheaper.
europaxs wrote:
The biggest advantage of the Rotax is it’s ability to run without leaded fuels, not in fuel savings, I think.
boscomantico wrote:
…which all Lyco / Conti engines in the same power range can do just the same…
The Lycos do not tolerate ethanol
http://www.lycoming.com/portals/0/ourinnovation_fuels_unleadedfuels_part_2.pdf ,
whereas the Rotax runs happily (and is approved) for 10% Ethanol.
That is a major difference. When I wrote unleaded fuel I didn’t mean exactly UL91, rather ALL unleaded fuel with at least 95 RON and <10% Ethanol.
europaxs wrote:
whereas the Rotax runs happily (and is approved) for 10% Ethanol.
How much ethanol can a fuel system in a given airframe take is also a question. AIUI “aviation grade” mogas shouldn’t contain any ethanol.
I refuel with E 5 (<5% ethanol), you’ll rarely find 5% in it, rather something like 1-2%. You simply don’t have to bother all the time. But true – the fuel-system has to be ethanol-resistent as well.
Technam would be smart to upgrade the P2006T with the new Turbo Rotax 915 135hp engines.
