U.S MPG vs. Imperial MPG
 

Lately I have seen commercials and specifications here in Canada for fuel efficiency of vehicles. Most will show L/100Km and MPG. However, the MPG number seems very high compared to the L/100km, and if you convert them, they don't work out based on U.S. MPG. Are they using Imperial MPG for this? If so, they are probably making people think the cars are getting better mileage than they actually get. It can be confusing. How is a car's mileage rated in the US?

miles per US gallon in the EPA's test lab under controlled conditions.

1 US gallon = 0.83267418 Imp. gallon
that means you'll actually get a more favorable mpg because it's a larger gallon thus more miles per gallon.

what MPG and L/100km are they advertising? I have it all down in excel to convert them.

That is exactly what I am looking at. However, you are understanding it wrong. If one US gallon equals .8326 Imp gallons, then an Imperial gallon is larger. An imperial gallon is larger than a US gallon. Therefore, higher MPG, which is exactly what I am getting at.

Here is what is on Wikipedia:

* U.S. liquid gallon is legally defined as 231 cubic inches, and is equal to 3.785411784 litres (exactly) or about 0.13368 cubic feet.
* Imperial (UK) gallon is legally defined as 4.54609 litres (≈ 277.42 cu in), which is about 1.2 U.S. liquid gallons.

Thanks for the post 'acetone marty', that makes since now. It would be much easier to have a common MPG to use in all countries, instead of getting MPG ratings between Canada and the US mixed up. My current MPG average for my car is 35.04 MPG (US) which is 42.1 MPG (Imperial)!

Yes, you're right. yesterday was a long day already by 4pm. imperial gallon is larger. fixed it

Please consider to use this site to calculate your mpg numbers. It gives you results in US and Imperial gallon as well as metric terms and hence help avoid confusion:

https://oee.nrcan.gc.ca/transportatio...ut.cfm?attr=16

Good site. Thanks.

:) Glad you like it. Just one more here. Personally I prefer the simplicity of the first one but this one can help with the conversion of other types of units:
https://www.rockymountainmoggers.com/convert.html :)

BTW I think any testing done for the Canadian figures is on rollers only, and aerodynamics don't figure. There's some kind of adjustment for body type or vehicle type, but it's kinda whacked. I think it's been messed up for years.... saw an old ad in an '80s Readers Digest for a "55mpg" Plymouth Caravelle, which was an extended K car platform, and couldn't square that with an objective reality. I think according to the Canadian figures we have 40mpg minivans up here...

Edit: oh strangely, those cars that can actually get 50mpg like the Echo/Yaris don't score too much more than what they actually get.