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by gngeal 4768 days ago
The driver liked the car but said the biggest problem is mileage. 9-10 mpg in the city.

Since when is gas measured in gallons? Around here, we've always had it measured in cubic meters at atmospheric pressure.
1 comments
cfesta9 4767 days ago
I see how this statement is flawed. Thank you for pointing that out. So this car gets 9-10 miles per (your choice of wordage). Also around murica we measure gas in gallons. hahaha.
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gngeal 4767 days ago
Oh, I should have written Europe::gas, which is not the same thing as America::gas or Europe::petrol. The problems with using mpgs for CNG and LPG vehicles, of course, are many:

- CNG, LPG, and gasoline have significantly different mass density, so you can't compare the fuel tank sizes easily.

- CNG (methane), LPG (propane/butane), gasoline (octane), and diesel have different energy density, so it doesn't make sense to compare mileage by volume.

- They also may have slightly different energy efficiency in the engine.

My conclusion is that the best way is probably miles per MJ of the calorific value of the fuel.

Or, you know, you could simply state miles per $ of the fuel price + power train depreciations/maintenance, or even include the vehicle's TCO, which is what intensive car users are aiming for anyway. :-)

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