On Thu, 20 Jul 2017 09:00:41 -0400,
wrote:

The problem is getting an accurate reesult over varying conditions.
Getting extremely accurate results in a fixed condition is simple.
Same road, same speed, same weather conditions, repeatability is
excellent and simple equipment can be very accurate. For instance,
calibrated fuel supply, running start on measured distance at
predeteermined speeds - make modification and retest.

I agree. But I suspect most people don't understand what you just wrote.

My rule-of-thumb take-it-with-a-grain-of-salt "assumption" is that anyone
quoting decimal places using "home methods" is probably not understanding
what you just said.

There's now a separate thread, with science guys on it, over he

What is the realistic accuracy & precision of typical consumer MPG
calculations (tripmeter miles/pump gallons)
https://groups.google.com/forum/#!to...ir/PT3YdPClM7g