John,
How many wheels does a metric 18 wheeler have?
Hokie,
1/5 of a foot is no tougher than 1/6 of a meter.
I teach a lot of classes to pretty mixed audiences all over the world and I've gotten tired of fighting over system names. I now label one column "SI" and the other I follow the JM Campbell convention and use "fps" for "feet, pounds, seconds". It isn't exactly right (since oilfield units and psi don't fit the fps system, and dyne/cm is not SI), but I don't have to argue about whether it is "English", "Imperial", "Old", or just "dumb".
I always ask a new class what units do they use for natural gas production volumes. I get such a range of answers (in one class of 20, I got 13 different units). In the U.S. the basic volume is MSCF/day. In Canada it is E3m3/day (thousands of cubic meters, at "standard" conditions is implied but the standard is anything but). In Australia they pretend that all gas is 1000 BTU/SCF and convert to Joules (an MJ is an MCF with that silly assumption). I think it was Namibia that used kg/hr, which really makes the most sense to me but everyone else wants to use volumes tied to a rock (STP or some variant). After about half way around the room we always agree that MSCF works for more of us that any alternative. Almost no one like m^3/day because the numbers are too damn small.
David