Not 10 seconds after Wilbur cracked up the Flyer that cold December morning at Kitty Hawk, Orville must have asked, “whats this gonna cost me?” And weve been asking ever since, never more so than now as the future of 100LL hangs in the uncertain balance between readily available and extinction. As potential replacements loom hazily on the horizon-and frankly, there arent many of them-its fair to start asking what they might cost. Or to cynically turn the question on its head: Does anyone have the first clue?
No Ones Asking
At this stage, were aware of no industry wide economic analysis of what we view as the top three contenders, 94UL, Swifts 100SF and GAMIs G100UL. One reason for this is that the find-a-new-fuel effort has been biased toward the regulation and approval process at the expense of probing the refinery economics. Second, the two 100-octane options are works in progress, so making cost estimates is a smell test at best. Third, predicting future fuel prices of any kind is a black art governed by market forces with potentially wild variables.
Nonetheless, we think its worth asking so that owners can begin to form the kind of opinions that will eventually gel into genuine demand for one product or another. The overall outlook? At the moment, all three contenders seem within range of cost economics of current 100LL. But “in-range” is a slippery term.
94UL
Ignoring the argument over required octane for a moment, 94UL would seem to be the simplest solution. Its just 100LL without the lead; basically juiced up mogas, right? Unfortunately, no. As with all fuels, refineries make their 100LL octane numbers in various ways, depending on how theyre physically configured and what their economics are. Some refiners dose their avgas heavily with aromatic hydrocarbons-toluene, usually-while others use little or none. Lead concentrations vary, too. Typically, avgas blends are primarily made with alkylates-a branched hydrocarbon chain, isoparaffinic material, made by combining straight-chain light hydrocarbons with isobutane in the presence of liquid acidic catalysts. Alkylates are typically of high-octane and they represent the top-of-the-line components that refiners have available when making any kind of gasoline. But not all alkylation is created equal. Some refineries yield higher octane alkylates than others and/or what they produce is cheaper.
So knock the lead out of one avgas and you might be left with something close to 94UL, but take it out of another whose alkylation is of lower octane and you have something less. And therein lies the cost crunch.
A refiner with a lot of capacity for good quality alkylate might be able to blend avgas without the lead, adjust the aromatics and deliver a 94UL without sweating, while its competitor