Originally Posted by iahphx

Indeed, it's not perfect. A couple of days ago, I tried siphoning from a half-full 5 gallon can. It didn't work so well. Today, I tried from a full can. After some vigorous shaking, it worked. Pretty well, actually. But it doesn't get the last third of a gallon or so. So I still need the funnel. It does make the job easier, though. If you have a high vehicle, it can be very heavy holding a full 5 gallon can up to the gas tank opening (less of a problem on a regular car). Using a funnel for just the dregs is easier.

That said, I suspect there's a better solution, and my suspicion is an electric siphon.