No need for your S-7 friends to go out of their way to get E0, they must be new to the game, the Rotax burns E10 just fine, I've burned lots of it and cannot tell any difference for the life of me. I have no idea what you mean by their carb issues. I do continue to buy and store E0 in my home bulk tank though. And, if their field elevation is over 2500' ASL and if they had the "Zipper BigBore Low Comp" mod as do I, they could burn REGULAR E-10 no less.
My only limitation with the S-7S is tire size, I only have 29's. Other then that, the air frame handles anything I can throw at it, and about 80% of my flying is off airport, and not at coastal elevations. Pic is from a few days ago, 8650', Idaho/Wyoming border, a place I've been into a lot along with similar. No big deal, dare I say, routine even. 3800 hours TT in type.
Today's update on my fuel burn. I flew to a 7800' high ridge 23 miles from my strip, making 85 MPH over the ground according to the GPS (averaged out by flying the opposite direction, close enough), empty other then me (150 lbs), tool kit, tie downs, and 24 gallons of mogas. Take off was 5460', and average altitude enroute was 6K or so, (my place is 1200' above the valley) temp was close to 80. Once at the ridge I started down low, at 4500', as I was trying to figure out how to get to the dirt road that lead to it. There was a trail on top I wanted to ride my ebike on, and if I drove to it (on a non flyable day of course) I needed to be able to find it. I got that done, and then figured as long as I was there I may as well follow the trail up the canyon, which I did, low level and climbing as needed to maintain about 100'. Once on top, I decided to continue following the trail along the ridge top, now just 30 to 40' above it, at about 65 MPH and one notch of flaps. I went for a couple miles, and then saw a clearing and after eyeballing it, landed it. After a bit I took off and flew roughly towards home, playing around on the way, mostly low level screwing around, nothing but open country/ag, until I had to climb back up to 7 K to get over another ridge, then the last leg towards home at 6 K, again low level.
I had carefully noted the fuel level in the wing tank sight gauge, and marked it on a strip of masking tape. After the plane was back in the hangar, I filled up a 5 gallon jug and as usual used my fuel transfer on the floor to pump it up into the mains, I rarely refuel at home in the conventional manner. The fuel level reached the mark made earlier, and i had fuel left over in the 5 gallon jug. I dumped that fuel into a gallon jug, it was 1/2 gallon, so the total fuel burn for the flight was 4.5 gallons. Just now I went out to the hangar, like most my plane draws unevenly out of the tanks (I'm plumbed to draw off both, no selector valve, and my mark was on the side that always drains sooner) and as expected, now that it was sitting a few hours, the fuel level between tanks was even. I saw I was now above the mark made earlier, so let's call it 4.25 gallons, and the Hobbs meter said it was a 1.5 hour flight total. That works out to 2.83 GPH. Point bein, the Rotax is frugal to start with, but with a few simple mods (Hacman Leaner, 1" crossover induction tubes, 78" Prince P tip prop, and Hal Stockman's Zipper BigBore mod, the low comp version) it is very easy to get it below 3 GPH. I routinely get this type of consumption for my local, just screwing around flying, loaded for bear and going somewhere is the only time I even approach 3.5, usually 3.1 -3 and that would be if I'm trying to beat the weather or am in a hurry. Considering this is low octane mogas (or could be, actually my best source for my bulk tank's E0 only offers premium, the only place in my town that offers regular E0 has a $75.00 card limit at their unattended pumps, so filling my 300 gallon bulk tank there is impractical), that is economy, but still with great STOL performance, that keeps me happy. Seriously thaefeli, the next time those guys with the 7's brag about their 3.5 GPH fuel burn, razz them about it! It's way too much, tell them I said so! I'll let someone else do the math on how much I save with these numbers, flying my average of 200 hours a year, over flying a Super Cub, Maule or 180, but it is not chump change.
