Okay, I might be the last person on earth to discover this, but . . .
I went out to change the oil on our Troopy this morning, and discovered that somehow all my funnels had ended up at Ravenrock, our desert place . . . 40 miles away. No problem: I had an empty gallon bottle of windshield washer fluid, so I cut off the bottom to make an impromptu funnel.
And, lo and behold, when I inserted it into the fill port of the Troopy it engaged more or less perfectly with the threads. I was able to screw it in and employ both hands to control the oil pour. Plus, when I was finished I screwed the cap back on the bottom of my new “funnel,” so the residual oil wouldn’t seep out into the box where it’s stored.
I’m curious how many vehicles this would work on. Going to try the rest of ours . . .