On 07/20/2017 12:14 PM, Mad Roger wrote:
Do they realize that you have to keep the *entire* test at the same
atmospheric conditions, and where the typical mom and pop doesn't do that
for an entire tank of gas (which might take a week to use up during which
time the atmospheric conditions change greatly).

While I question pop's back of an old receipt calculations, the question
isn't what the mpg would be for a known quantity of fuel at STP, but how
many real world miles were traveled with that quantity.

For example, when I was driving a truck I would often get close to 7 mpg
going east on I94 in North Dakota. Going west with the same load I would
be lucky to get 6. If you don't know why you've never been to North
Dakota. However, as far as planning my fuel stops, standard atmospheric
conditions didn't count.