It's possible to use auto fuel in your aircraft, but there are things you have to consider, and things you have to do. [File Photo: Adobe Stock]
Key Takeaways:
Using automobile fuel in an aircraft is only legal and recommended with a Supplemental Type Certificate (STC) for both the engine and airframe, which often pays for itself through fuel cost savings.
Without an STC, using auto gas is a violation and can lead to long-term engine problems due to differences from aviation fuel, such as lack of lubricating lead.
A critical concern for auto fuel use is ethanol content, which can severely damage seals and gaskets, attract moisture, and cause engine failure if the aircraft's fuel system is not ethanol-tolerant.
Engine manufacturers like Lycoming permit auto fuel only if it meets strict specifications (e.g., ethanol-free, specific octane), warning that non-compliant fuel voids warranties and risks engine damage.
Every student pilot hears this dire warning about using automobile gas in an aircraft engine that was not certified for it. These warnings are usually accompanied by a story about engine failure and an unscheduled off-airport landing, which often occurs shortly after takeoff.
CREATE A FREE ACCOUNT
Sign up to keep reading
Create a free account to continue. Already a member? Sign in below.
Meg Godlewski has been an aviation journalist for more than 24 years and a CFI for more than 20 years. If she is not flying or teaching aviation, she is writing about it. Meg is a founding member of the Pilot Proficiency Center at EAA AirVenture and excels at the application of simulation technology to flatten the learning curve. Follow Meg on Twitter @2Lewski.
