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Since May 2016, UL94, now a product of Swift Fuels, is available for sale at dozens of airports in the United States. Swift Fuels has an agreement for distribution in Europe.cite-ref-aopa-september-13-2016-94ul-72-0[71]cite-ref-swift-fuel-product-94ul-73-0[72]cite-ref-ainonline-6-april2016-94ul-102-ul-74-0[73]

UL94 is not intended to be a full replacement for 100LL, but rather is designed to be a drop-in replacement for aircraft with lower-octane-rated engines, such as those that are approved for operation on Grade 80 avgas (or lower), UL91, or mogas. It is estimated that up to 65% of the fleet of current general aviation piston-engine-powered aircraft can operate on UL94 with no modifications to either the engine or airframe. Some aircraft, however, do require a FAA-approved Supplemental Type Certificate (STC) to be purchased to allow for operation on UL94.cite-ref-swift-fuel-product-94ul-73-1[72]cite-ref-75[74]cite-ref-76[75]

UL94 has a minimum Motor octane number (MON, which is the octane rating employed for grading aviation gasoline) of 94.0. 100LL has a minimum MON of 99.6.cite-ref-astm-d910-16-4[16]cite-ref-0-61-2[60]

AKI is the octane rating used to grade all U.S. automotive gasoline (typical values at the pump can include 87, 89, 91, and 93), and also the 93UL fuel from Airworthy AutoGas.

The minimum AKI of UL94, as sold by Swift Fuels, is 98.0.

Concurrent with the addition of UL94 to ASTM D7547, the FAA published Special Airworthiness Information Bulletin (SAIB) HQ-16-05, which states that "UL94 meets the operating limitations or aircraft and engines approved to operate with grade UL91 avgas," meaning that "Grade UL94 avgas that meets specification D7547 is acceptable to use on those aircraft and engines that are approved to operate with ... grade UL91 avgas that meets specification D7547."cite-ref-77[76] In August 2016, the FAA revised SAIB HQ-16-05 to include similar wording regarding the acceptability of using UL94 in aircraft and engines that are approved to operate with avgas that has a minimum Motor octane rating of 80 or lower, including Grade 80/87.cite-ref-78[77]

The publication of the SAIB, especially the August 2016 revision, eliminated the need for many of the UL94 STCs being sold by Swift Fuels, as the majority of the aircraft on the STC's Approved Model List are type-certified to use 80-octane or lower avgas.

On April 6, 2017, Lycoming Engines published Service Instruction 1070V, which adds UL94 as an approved grade of fuel for dozens of engine models, 60% of which are carbureted engines. Engines with displacements of 235, 320, 360, and 540 cubic inches make up almost 90% of the models approved for UL94.cite-ref-lyc1070-22-3[22]

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