I have C172I (1968) with Lycom. o320 E2D engine which came with a stc for Mogas.
Today have been told by a Instructor at a AME (Airplance Mechanical Engineer school) in Canada, that with Mogas one is legally only allowed to fly up to 5000 ft, that same needs to be placarded in the cockpit with all restrictions as well.
I can not believe this is correct, why would it be allowed below 5000 ft but not above?? Make no sense to me, either it is legal or not and if there is a valid STC I think it would be legal without restrictions.
does anyone have info on this subject and or know the specific law in Canada on this, also, experience with Mogas versus Avgas, so far, I have been using both and have not had any problems with either>
This clip is from the EAA website pertaining to the use of Auto Gas.
"Another area of concern is high altitude vapor lock. All EAA flight test programs have included an evaluation of the adverse combination of volatility and temperatures, plus demonstrated climbs to the service ceiling of the aircraft, (which in the case of the Cessna 182 was 21,034 feet density altitude), and to also include some periods of cruise at altitudes above 7000 feet. Each airplane that we have flown in our 500-hour flight test program successfully completed these tests."
We know of no such altitude restriction when using an approved Auto Gas STC.
See their site at [www.eaa.org] for additional information.
I fly my 1956 172 with an 0-300B using premium mo-gas at least 50% of the time. Its made a big difference in the leading on my valves. The previous owner ran 100% 100LL and had to grind at least one valve each 100 hour inspection. I had the same problem during my first inspection.
Since running mo-gas at least half the time I've had no problems in nearly 2 years now. I routinely fly 7500 to 9500 and have never had a problem. My engine also seems to have imnproved fuel economy (8.4 gph vs 9.1 on 100LL) and slightly better climb performance. I use an EGT to lean and lean to the same point with both fuels.
I have the Peterson STC and follow directions religously.
I have a Mogas STC, but never use the stuff. First of all where I fly I can't find it. I would have to buy gas cans and illegally fill the aircraft, which I would never do unless being attacked by the local natives and need to flee.
I fly with 100 LL and have not had any problems in 1000 hours on my C172M (1973)Lycoming O320 E2D, 150 hp. I get about 8.4 gph. I cruise between 108 and 110 knots true air speed routinely at rated RPM for 75 % hp. Atmospheric conditions affect hp and efficiency wherease, gross weight, aircraft center of gravity, verical components to the winds, surface friction, and airplane rigging also factor into fuel consumption during flight.
I didn't like Mogas because if not flown a lot it will emulsify much sooner than Avgas. If you routinely fill your tanks, I wouldn't think that would be a problem.
Just a note: I only run the autofuel when I know I'll be flying the plane within a week and I usually fill the tanks just before leaving. Avgas is 'stabilized' and auto isn't so I've been unwilling to take the chance on a problem with letting it sit in the tanks. I've never had a problem but I've never let it sit either.
gary
Mine came with the plane but its from peterson. The EAA also has one. I was looking at them before I discovered it in the logs / papers that came with the plane and it looks like both go for about $125. I figure I save around fifty-cents / gallon on average (much more since Katrina). I'm going to fly close to 200 hours this year at about 8 gallons / hour. I fly on autogas about half the time so it works out to about $400 / year. Its not much in the grand scheme but it all helps. My big reason for using the mo-gas is to cut down on the leading on my exhaust valves and its really cut down on the problem so its worth it even without the cost savings. I have 4 5-gallon cans that I bring the fuel in to my hanger. We can't store fuel there so I need to bring it with me each time but it hasn't been a hassle. I flew to South Dakota last year and found mo-gas at about half the airports I stopped at. Its not common to find it in Texas though so I usually use avgas at the other end.
If you are flying a standard 150hp 320 you should be saving much more than 50 cents on the gallon. The 320 is STC'd for 'Regular' auto fuel. My 360 (180hp) is STC'd for 'high test' and I am saving $1.75 a gallon.
