Just done that! Nothing special, indeed, but decided to share my first experience with the beginners or those on the fence.

I've got a small generator recently and a 5 gal plastic red canister for the gas supply for it. My first mistake was to fill it with the Premium gas, as the generator's manual recommends. Though, I'm refueling my car with the Regular one (also per manufacturer recommendation). So, when the time to rotate came (I've decided on a 6 month cycle with the regular "Sta Bil" additive), I had to wait until my car tank was completely dry (it's a no-no to mix the two grades, a.f.a.i.r.) and then again one more time prior to a regular refueling. Quite nervous thing to me, as I rarely had it even half empty, and only once in 16 years saw the "fuel low" light lit. By the way, needles to say, but the 6 mo.old gas (with stabilizer) has worked flawlessly with all the high octane benefits immediately evident.

The second problem I dealt with was the car refueling from that canister. It has a "safe vapor release valve" type nozzle, which is not suitable for direct car tank refilling (too short, too thick). So, an adapter is needed. I have misplaced the original one a while ago and forgot even how it looks like, but by an accident, have found a similar adapter in my storage, which probably came with some other canister, or maybe with a hand pump. It fitted well over the vapor release nozzle and was long enough to open the tank's valve, even though the tank's lid was interfering with the canister's side a bit. However, it turned out that it has lacked very important tolerances at the intake side, preventing the air coming through that fancy nozzle and replacing the empty volume. As you can imagine, the created vacuum resulted in multiple approaches, many spills, and allowed me to set a new record in car refueling at the whopping 5 minutes per gallon. A good 25 minute workout with the 40 pound weight though.

Since then I have permanently attached the original adapter right to the canister's handle with a stripe of gorilla tape (in a resealable way) and a paracord lanyard (made a hole in the adapter's collar). Also I have figured that the best way to quickly refuel with it is holding the canister upside down. Though, the Regular gas is yet to be tested with the generator.