Yes, I haven't made a science out of it (yet), maybe that 5mm OD pipe was a bit tall. We do not live in the WA emptiness.
But that's what I had, a few of, and they are 50mm long. Maybe 1½" suits better; next time I'm there, I might take a bit off. But for me the important thing is that I have some distance left after I get the warning.
This time I got the warning going uphill, after leaving a small village. And for the live of me, I don't think it did more than 5 miles, if that. Put the bike on it's side & got another mile, maybe, and then it was walkabouts. Till the next village, where I bummed some.