Canadians, How Do You calculate MPG?

This was an interesting quirk that popped up recently and I'm curious to know how we handle it.

I was recently asked to calculate the Miles Per Gallon on the truck I'm driving and thought it would be a rather simple adventure with my calculator. I'm used to just figuring out how many litres per 100km I consume so I figured this would be a simple matter of converting litres to gallons and kilometres to miles.

What I hadn't though of though is that of course, up here we use Imperial gallons as a unit of measurement and you Yanks use US Gallons. Since we're in Canada, one would think that we use Imperial gallons but then, since trucks are all over the continent, maybe US is the standard measurement?

Canadians, do we use US Gallons or Imperial?

 

Well that's just it. No one seems to know much about what is considered a standard and where that standard may find its geographical limits. I don't know if when I hear some one's getting 7 MPG if that's worse than it sounds, just what it sounds like or perhaps even better than it sounds.