Fuel octane explained.

[Don'tPanic]

Before Spyders are made electric we have to deal with gasoline. It's dirty, it smells and it's way too complicated. I never liked chemistry anyway.
I've seen too many erroenous threads and posts here to remain quiet, so here's everything you need to know about "Premium" vs "Regular" gas and which one is right for you.

Long Story Short (very simplified):

1. Modern Spyders run on Premium Gas, or for USA: octane rating of 91 (it's different in every country).
Here's from the owners manual: "Use premium unleaded gasoline with an AKI (RON+MON)/2 octane rating of 91, or an RON octane rating of 95". (See your owner's manual)
Yes, you can run your Spyder on lower octane fuels, but it comes at a cost (see #4)

2. This has nothing to do with how one grade burns hotter than another (it's the same), or how "Premium" is better than "Regular" (it's not)

3. The ONLY reason for this octane requirement is the engine compression ratio. That's it. Nothing more, nothing less. It's all about compression. Simple physics and chemistry.
Higher octane fuels resist to self-combustion due to the heat of the compression. The higher the engine compression, the higher the requirement for octane. Spyder engines have a very high compression ratio (12.2:1 for twins and 12:1 for triples) Any engine with compression over 11:1 has to have a "Premium" gas.
NOTE: I only looked up compression of modern Rotax engines. Yours might be different.

4. To those who run on "Regular" gas: your engine will knock. Here's what you need to know: "Burning fuel with a lower octane rating than that for which the engine is designed often results in a reduction of power output and efficiency. Many modern engines are equipped with a knock sensor (a small piezoelectric microphone), which sends a signal to the engine control unit, which in turn retards the ignition timing when detonation is detected. Retarding the ignition timing reduces the tendency of the fuel-air mixture to detonate, but also reduces power output and fuel efficiency."

5. "Premium", "Supreme", "Plus" and "Regular" terms are completely bogus and misleading. It's all the same gasoline. In fact, most of the gas stations use the same refineries. The difference is in additives. In simple terms: higher octane gas has more expensive additives and lower octane has cheaper additives. "Plus" grade gas is just a mixture of "Regular" and "Premium".

6. A more expensive, high octane fuel does absolutely nothing for the engine designed to run on lower octane fuels, however, a low octane fuel will damage or degrade performance and fuel economy of the engine designed to run on a high octane fuel.

If you want to know more, here's a good video: https://youtu.be/WYlk9C1o0nk
(I'm not affiliated with them in any way)

I hope this helps