On Thursday, July 20, 2017 at 3:34:32 PM UTC-4, Ed Pawlowski wrote:
On 7/20/2017 2:28 PM, dpb wrote:
On 07/20/2017 11:59 AM, Ed Pawlowski wrote:
...

Based on my checking over a tankful and what the meter says, they just
take an optimistic guess. It is always higher, but there seems to be an
explanation

https://www.edmunds.com/fuel-economy...s-fibbing.html


Roger Clark, senior manager of GM's energy center, explains that the
fuel economy gauge makes a calculation by counting the number and
duration of pulses made by the fuel injectors as they squirt gasoline
into the combustion chambers of the engine. The onboard computer system
divides the distance the car travels by this estimated fuel consumption.