Modern Vespa

Swift Fuels has been working to develop fuels that can replace leaded avgas (100LL) for the general aviation fleet in the USA. Recently I fueled up my little plane (powered by a Rotax 912 iS) at an airport that carries Swift UL94, so I thought about my scooter.

UL94 is a 98-octane unleaded fuel. Seems it would be a great fuel for a modern Vespa engine. Thoughts?

https://www.swiftfuels.com/products

I wonder if a California airport would let you fill up directly. I know Renner Petroleum up the coast will only sell you ethanol-free gas if you bring your own container.

I ran a couple tanks of ethanol-free on a recent trip to Nevada, and got 84 and 82 MPG respectively. In the hundred tanks I've filled up before that trip, I've only gone over 80 MPG twice with E10. I don't often ride over mountain passes, so it's hard for me to know how much of the economy was the clear gas and how much was the riding style.

Even if you could easily get clear gas from an airport and it increased your fuel economy by 10%, I doubt it's worth the hassle (in time, in distance-out-of-your-way, or in increased cost) to actually fill there regularly.

There was only one ethanol-free station in Carson City: it was 3 miles off main street and 40¢ more per gallon than the same octane E10. It's interesting to see the difference in different fuel blends, but even that in-town gas station isn't worth the hassle.

Thanks for the laugh. Having worked at a couple FBOs and fueled many, many aircraft of all kinds, I can just imagine what would happen if you tried to fuel a Vespa from a fuel truck. First of all, the nozzle won't fit. Even if it did, I can't imagine trying to regulate the fuel flow so you would only put a couple gallons in. There would be fuel everywhere.

What do you expect this fuel to do better than the fuel you are using now, and can you use it often enough that it does whatever that is? Riding out the the airport every time the fuel light comes on seems like it would limit how far you could ride on any given day.

I don't have any expectations of Swift being better, other than a higher octane and zero ethanol. My OP was meant to be more thought-provoking than reality. The airport that carries Swift is at least a two-hour flight away from where I live, so if I ever tried any in my Vespa, I'd have to bring it back in a gas can.

I went to the aitport once to get fuel. They thought I was nuts.

Most aviation fuel is extremely stable, and won't degrade over time, unlike most pump gas, which can go bad in as little time as a month. The vapor characteristics are tightly controlled, so its less prone to vapor-locking on hot days. The extra octane is of no use, however, unless you've raised the compression ratio.

Locally we have plenty of stations with ethanol-free, and more all the time. That is what I buy and use, exclusively.

Probably be great fuel to fill the tank with over the winter, if you store you Vespa, although pump gas with Sta-bil is just as good.

I've not seen anything definitive on how well Swift works with 2-strokes or 2-stroke oils, though. Not really an issue in the aviation world.

As an FYI, most aviation fuel has quite a bit of lead in it, and will poison the catalytic convertor, and possibly damage the O2 sensor, if you have those on your vehicle. Excessive quantities can even lead-foul your spark plug, a common issue in older aviation engines.

I used to have a friend bring me a 5-gallon can of 100 octane leaded, when I had my Airhead, and I'd put in a half-gallon when I filled the tank, as the bike was designed to run on leaded fuel.

Damn, 80/82MPG's I had a 2010 GTS 300 and now have a 2018 GTS 300 and I can't get past 60MPG's. I am guessing riding in NYC in stop go traffic no matter what fuel I could use Id see any improvement in economies.
Think we should see what fuels in what conditions (city stop/go versus country leisurely steady speed of 50-65mph) deliver best economies and power.

Over 91 octane is a waste and will promote carbon build up on the piston and cylinder head. Use it long enough and you will have to use it because of the raise in compression from the carbon build up in the cylinder.

Greetings:

One of the hotter builds of my Honda SA50 2-stroke was a 90cc with a 44.1mm ministroker crank and a 50mm bore. Compression tested over 165 - remember this was a 2-stroke.

There was no question of using pump gasoline on this one. Sunoco racing fuel is a hassle to get so for about a year I'd make a trip to the County airstrip for 4 gallons of 100 octane Low-Lead. There was no carbon build-up when I swapped for a different setup after about a year and 4500 miles or so. Also, it didn't Grenade on me. I had already made some Rookie jetting errors on previous builds and started to get a clue... See below.

So I use Premium here in NYC I know regular is 87 not sure what premium is 94 or 91. Have to check next time I fill up. I have noticed though that with 87 the engine sounds different for sure.

Any premium pump gas is fine. 91-93 is standard, using over 94 is going to start causing build up of carbon on a stock motor.