maybe i have a different style of "new" can? i got tired of trying to decide what fuel i had in what red can, so a few years back i bought yellow diesel cans. they have no vent hole to leak, and have the spout that has to be pushed down to release fuel.
i've posted here previously, and i understand that people are looking to find a solution so they don't have to lift a 5 gallon can, but what boggles my mind is the problems people are having with the newer cans. most tractors i've seen have fuel fills that are accessed from the top - be it hood or fender. these new can spouts work great with that style of filler. i will say that trying to fuel a car or truck with a side of the fender fill pipe can be miserable.
i can take my diesel can and tip it totally upside down and i don't spill a drop of fuel. while upside down i hold it over the fill pipe on the tractor and lower it. it starts filling the tank, and if the tank becomes full before the can is empty, it stops filling. when i take the can away the nozzle springs back to the closed position - no spills. also, since the filling is pure gravity, i don't have to hold the weight of the can. i just have to hold it steady from side to side. basically, once the can is over the fuel filler, i can leave one hand up there to steady it, and leave the other hand free for scratching myself, holding a drink, or whatever. with the old style cans i had to hold and tip it into the filler pipe, but not now.