Why is that? Is it because you need a more expensive octane booster to replace lead?
You'll be interested in whatever fuel works for your application when 100LL is no longer available, regardless of the price. Perhaps you've been living under a rock for the last 10-20 years or so, but that's the ultimate endgame here. You shouldn't expect any of the replacements to be cheaper than 100LL.
Essentially, yes.
I would expect that it's more about the low volume than about any specific component.
It's both. There's a few octane boosters e.g. toluene, that cost more than TEL (tetra ethyl lead) in the quantities they are being purchased at. (for G100UL, no idea about Swift) There's a lot of potential cost savings in distributing an unleaded product in trucking and rail cars. The quantities are too low to go in pipelines. There's also some good data on less engine wear and longer oil change intervals from G100UL testing.
You might notice my original post acknowledged the EPA will establish the endgame. Yes we're expecting leaded avgas to eventually go away. I crawled out from under that rock today
TEL is a very cost effective octane booster. The aromatic compounds used to make G100UL, for the most part, require more processing than just simple distillation of crude which increases cost. Yes, costs may be quite a bit disparate compared to 100ll upon first adoption at FBO's and this may improve with volume, but, over the long term, G100UL is going to cost a bit more than TEL boosted high octane fuel because of the aromatics cost.
That is part of it. It is also new, some start up costs.
Regardless, it will be made from refined petroleum products, just like all motor gasoline. These products are combined at a blending plant (which may be remote from the refinery) to formulate the desired end product. My point is that the aromatic components used to boost the octane rating are more expensive to formulate and will make the fuel, at a wholesale level, more expensive than 100LL. Economies of scale will likely reduce the original disparity but, due to the relatively low volume of avgas sold, I can't see how a product more expensive to formulate will have cost parity with a product cheaper to formulate. Even 93 octane is more expensive than 87 due to these facts. I look at 100LL and G100UL (or any UL) in the same light.
One would think. I’ll take a stab. The less unsaturated molecules (organic molecules with double bonds, also known as olefins) there are in a blend, the less degradation over time. If the new formulation contains just as few unsaturateds, it should be fine. I don’t think there are any special stabilizers in 100LL, it’s just “cleaner”. I’ll be corrected if wrong.
That's a bit oversimplified, but good enough for this group. The alkenes react with oxygen to form polymers- similar to how oil-based paints "dry". The oxidation products sometimes accumulate and clog carburetors or other parts, and is sometimes called "varnish" There are various phenolic compounds added to gasoline to reduce this polymerization.
