10 Mogas myths

Kent Misegades | GAfuels | March 16, 2011

The GAfuels Blog is written by two private pilots concerned about the future availability of fuels for piston-engine aircraft: Dean Billing, Sisters, Ore., an expert on autogas and ethanol, and Kent Misegades, Cary, N.C., an aerospace engineer, aviation sales rep for U-Fuel, and president of EAA1114.

Evidence of the growing interest in the use of affordable, lead-free, ethanol-free autogas, AKA, “Mogas,” in General Aviation is evidenced by Ben Visser’s recent article on the topic, The fuel of the future: Is it already here? and the results of a survey conducted by AVWeb. Further evidence is the overwhelming interest we’ve experienced to the introduction of the Aviation Fuel Club, the new Sport Fuel program, and thousands of comments on our petition calling on a ban of the blending of ethanol in Premium gasoline. There remains, however, some confusion about the pro and cons of using Mogas, something we hope to dispel below:

Myth #1 – Gasoline used in airplanes is unsafe. Fact – International standard ASTM D4814 is used for both fuel production and engine TC/STC certification. Mogas has been an FAA-approved aviation fuel since the 1980s and has had an excellent safety record.

Myth #2 – Gasoline is unstable. Fact – Modern gasoline remains stable for at least six months. Addition of some fresh fuel “rejuvenates” old Mogas. Adding ethanol to the fuel dramatically reduces its life.

Myth #3 – Gasoline is not as “clean” as 100LL. Fact – This is a problem of the past mostly eliminated through modern filters. Modern RFG (Reformulated Gasoline required in many parts of the US) is the cleanest burning gasoline made.

Myth #4 – Seasonal/regional formulations cause problems. Fact – Provided fuel remains ASTM D4814 compliant, this can be managed.

Myth #5 – Mogas is less “powerful” than 100LL. Fact – 91 octane E0 Mogas has 3%-5% more BTUs/gallon than 100LL. Lead deposits from 100LL can reduce power, though.

Myth #6 – Higher octane is always better. Fact – Only if needed for anti-detonation. Octane does not increase power. Higher octane is always more expensive, though.

Myth #7 – You can’t find ethanol-free Mogas. Fact – PURE-GAS.org lists more than 2,600 sellers across the country. The Aviation Fuel Club will help you find suppliers who deliver to airports.

Myth #8 – Gasoline producers won’t sell E0. Fact – Perhaps not at retail stations, however many fuel terminals around the country sell ethanol-free fuels to airports, marinas, farms, etc.

Myth #9 – A Mogas pump is too expensive. Fact – The Aviation Fuel Club will help find low-cost options, which might mean a small military surplus fuel trailer. U-Fuel has developed a line of smaller, self-service Sport Fuel stations ideal for GA airports wishing to add mogas.

Myth #10 – Mogas at airports costs too much and takes revenue away from airports. Fact – Mogas is typically $1-$3 cheaper than 100LL and makes its seller a profit. Airports selling mogas recoup revenue lost to self-fuelers, help sport aviation and flight schools grow, and retain the same flowage fees as 100LL sales. They also make real reductions in lead emissions, a serious public relations issue for General Aviation.