VP Racing and LyondellBasell are developing UL100E, an unleaded aviation gasoline, through the FAA's Piston Engine Aviation Fuels Initiative — global R&D work, not specific to any one VP Racing region.

 

VP Racing and LyondellBasell joined forces in 2018 to build an unleaded aviation gasoline for the FAA's Piston Engine Aviation Fuels Initiative (PAFI). In late 2023, their fuel became the first unleaded candidate to pass a 350-hour durability test in a turbocharged Continental TSIO-550-K piston engine, clearing it for full-scale PAFI testing. The two companies are now pursuing an ASTM test-fuel specification, and Phase I of ASTM D7826 materials-compatibility testing is done.

Materials compatibility

A subset of full materials-compatibility testing on sealants, fuel bladders and elastomers, performed per the FAA's mini-MTAC protocol.

Engine performance & fuel properties

Rated-power checks on a Lycoming TIO-540-J2BD to compare engine operational parameters and certificate of analysis to 100LL.

Performance & detonation

Comparative testing between minimum-specification 100LL and the test fuel, performed in an altitude test cell on a Continental TSIO-520-VB engine.

Mini-durability

An engine test evaluating deposit-forming characteristics during a §33.49 350-hour endurance test on a Continental TSIO-550-K engine.

 

 

Fuel information

Why an unleaded avgas

  • The EPA issued an endangerment finding for leaded AVGAS in 2023, which would end leaded aviation fuel by 2030.
  • UL100E is compatible with 100LL in all proportions, with a synergistic octane response.
  • Fuel economy is similar to 100LL, and the anticipated price is on par with 100LL.
  • No additional fees to use this fleetwide-certified fuel, unlike STC fuels.
  • PAFI authorization and ASTM specification progress concurrently for UL100E.

For updates on the program, see flyeagle.org .

 

FAQ

Frequently asked questions

Have you seen any valve seat recession with your fuel?

Our fuel showed normal valve seat recession after a 350-hour endurance test in a Continental TSIO-550-K engine.

When will the fuel be available?

Commercial availability follows fleet-wide FAA approval, with the rate of deployment depending on airport readiness to transition from 100LL and the availability of a production fuel ASTM specification.

Does using the fuel require an STC?

No. The fuel does not require a Supplemental Type Certificate, although it needs to be added to a plane's placard. Obtaining an STC to use a different unleaded fuel could preclude the use of this fleet-wide-approved fuel without added modifications and costs.

How does the fuel affect maintenance intervals?

The fuel passed a 350-hour durability test in a TSIO-550-K engine without operational issues, with only routine spark-plug cleaning at 100 hours and none needed in the last 200 hours — which may allow increased maintenance intervals compared to 100LL. Engine oil also showed drastically reduced lead content over the test.

Is the fuel a drop-in for 100LL?

No unleaded fuel performs identically to FBO 100LL under every condition in every engine. PAFI testing is designed to identify any performance differences between UL100E and 100LL to ensure flight safety for the entire fleet.

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About this page

  • The UL100E program is a global VP Racing / LyondellBasell development running through the FAA, not a VP Racing Europe product. It is described here because visitors ask about it.