On Wed, 19 Jul 2017 23:04:35 -0600,
rbowman wrote:

I'm just curious how close do you think you can get to "accurate" gas
mileage calculations using the classic odometer plus fill it up to guess at
the gallons used method?

Who uses the classic odometer method? This is the age of computers.

From what I read long ago, we're not going to get anywhere near decimal
place accuracy at home, but I need to check this out to be sure of my
figures before I can argue it effectively with you.

Here's a seemingly expensive "fuel economy meter" which shows the
complexity of calibration, heated probes, high-speed sampling, auto zero,
etc. whose specs show a "resolution" of "± 2% reading" and a "repatability"
of "±2 % of reading" with a "span drift" of "±2 % of reading"
http://mustangae.com/products-servic...+Economy+Meter
http://mustangdyne.com/mustangae/upd...09/MAE-FEM.pdf