Aircraft owners choose automotive fuel (mogas) rather than aviation fuel (avgas) for a variety of reasons. The primary reason is cost. The savings in fuel prices between auto fuel and avgas are quite significant. In an airplane using 15 gallons per hour, a savings of only 50 cents per gallon will be $7.50 per hour less than the cost of using avgas. In 200 hours, this adds up to $1500.00. Savings of even half this amount would clearly justify the installation of an auto fuel STC. If you use auto fuel, by the time you run an engine to TBO you will have come very close to saving enough money to buy the next engine.
Maintenance costs are also reduced when using auto fuel. Many of our customers use auto fuel simply because their airplanes run better on it than they do on 100LL which, despite its name (100 Low Lead), contains twice as much lead as regular leaded auto fuel prior to the lead reductions which took place in 1986. This excess lead contributes to a host of problems, including fouled plugs and sticking valves.
Randy Schmerheim of Traverse City, Michigan
purchased our 30,000th mogas STC for this Cessna 150
Today many pilots are switching to mogas simply due to an increasingly limited supply of 100LL. In many regions of the world it is next to impossible to find 100LL at any price. In many parts of Africa, Asia, and the Pacific if 100LL can be found at all, the cost is so high as to be prohibitive.
Petersen Aviation has been doing research on the use of automotive fuel for aircraft since 1983. Forty-eight different engine types and more than 100 airframes have been approved since we began conducting our tests. Included in these approvals are nearly all 80/87 octane engines, and the vast majority of airplanes in which these engines were installed. Several high compression engines are approved for the use of 91 octane auto fuel including the 180 horsepower 0-360 and the 0-235-L2C. Our STC's are accepted world wide.
Auto fuel is safe for use in approved aircraft. Over twenty-five years of use has clearly demonstrated the suitability of this fuel for General Aviation aircraft. Over 34,000 airplanes world wide are now using a Petersen STC. Most foreign countries accept U.S. auto fuel STC's or have approved them in conjunction with localized Flight Manual Supplements.
The use of auto fuel is the best thing that has happened to General Aviation in the last three decades. In an era when the cost of flying has inflated to ridiculously high levels, automotive fuel STC's have done more than anything else to reduce those costs.
http://www.autofuelstc.com/autofuelstc/pa/Start_Here.html
