San Diego’s Montgomery-Gibbs Executive Airport (MYF) sold more leaded aviation gasoline than any other U.S. general aviation airport, raising questions about the challenges of transitioning piston aircraft to unleaded fuel.
The investigation, published Oct. 18 by nonprofit newsroom inewsource, found that more than 1 million gallons of leaded avgas were sold at the city-owned airport over two years. Sales in 2025 reached their highest level in more than a decade, according to the report.
In November 2024, San Diego introduced an unleaded aviation fuel option at the airport but sales have been minimal. According to the investigation, Crownair Aviation, which partnered with the city to distribute UL94, sold just over 24 gallons of the fuel during the two-year period examined.
The figures highlight a key hurdle in the transition away from 100LL: fuel availability does not guarantee compatibility across the fleet. UL94 is approved for certain piston aircraft but cannot replace 100LL in every airplane. Broader adoption will depend on fuel approvals, distribution and availability for aircraft owners and flight schools.
The report also examined potential lead exposure in communities surrounding the airport. Flight paths pass over or within two miles of more than 30 schools, according to the investigation. However, San Diego County’s childhood lead-prevention program has not conducted targeted testing of children living near the airport.
Meanwhile, the FAA’s Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative aims to transition the piston fleet to unleaded aviation fuel by the end of 2030 while maintaining safety and avoiding disruptions to general aviation operations.
The UL94 is priced not to sell at MYF. Maybe to either a) show there’s no demand for it or b) avoid the hassle of having to re-stock. But maybe it’s simply because c) the vendor is pricing it really high for its own reasons.
No surprise here. The wholesale price of the Swift unleaded is said to be about 2 dollars more than the leaded alternative. Of course it is not because the Swift UL 94 is an exotic blend of expensive hydrocarbons infact it Is for the most part just 100LL without the lead. So these high costs are associated with distribution costs mainly.
At this airport this fuel is only available at a fuel island pump and no available off a truck and the fuel is a lot more expensive than 100LL about 2 dollars more.
Currently the price of Swift UL 94 is $10.99 per gallon off an island pump at this Airport. At some other airports in California the city’s subsidize this product to keep it at the same price as the 100 LL.
At one of the airports that they did a lead study of the soil, it was closer to an old long defunct drag way that closed up in the late 70’s, than the airport. Another article i read was that leaded aviation fuel, which is low lead, the yearly total of all fuel pumped, is less than what unleaded fuel gets pumped in one day.
Not only was 94UL significantly more expensive than 100LL at KMYF, but it appears (based on online comments) that CrownAir would not allow pilots to fuel with 94UL unless they could produce an STC for the fuel, right there, on the ramp at the time of fueling. Those two factors would definitely limit adoption. I fly behind a Rotax 912 for which a 94UL STC isn’t required, so I probably would not be able to purchase 94UL at KMYF.
I asked Reid Hillview Airport if their UL 94 that is available self service requires an STC to use the pump. They said no all you need is a credit card.
When I went to Santa Monica, they had self service UL94 Fuel there and once again all you needed was a credit car, no policing.
This issue of lead in 100LL avgas is just nonsense. Stop the efforts to eliminate 100LL.