Thread: What is the realistic accuracy & precision of typical consumer MPG calculations (tripmeter miles/pump gallons)
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Default What is the realistic accuracy & precision of typical consumerMPG calculations (tripmeter miles/pump gallons)
On 07/23/2017 1:32 PM, wrote:
On Sun, 23 Jul 2017 11:21:22 -0500, wrote:
....

I didn't try to find what Canadian limits are -- I presume they must be
somewhat more stringent in order to match, more or less, the size of the
measurement interval? You know?

I do not know the requirements or test results today, but I DO know
back when we had mechanical meters our pumps (at the stations where I
worked)were never out by more than a couple oz in the 5 gallon
calibration, and the new electronic metering pumps (deployed when we
switched from imperial Gallons to Liters) were "significantly more
accurate" in metering. The accuracy changed a bit with delivery speed
on the mechanical pumps - can't remember if the change was that the
read higher or lower with reduced pump speed, but the variance was
quite low. The electronic meters were supposedly less susceptible to
volume arrors based on fuel velocity.
....

As noted, being they're dispensing quantities measured in units that are
roughly one-fourth the size one would suppose tolerances would be
adjusted similarly. The 0.5% error with the US compliance standard
would be almost 2% which seems as would be excessive in comparison to
what a governing consumer-protection function would deem adequate.

Nothing came up in the searches I did, but I didn't look for non-US
data, either, so being in US not surprising what I found was what I
found...

Anyways, I think we can put the subject to rest...

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