On 07/20/2017 3:32 PM, trader_4 wrote:
....

Until proven otherwise, I'd say what he's saying there is what you
say and what I would expect, that it just uses volume of fuel
injected and miles traveled.

That's certainly what the Buick displays indicate--if you reset then the
initial instantaneous and average are identical and you can watch the
average settle down as each instantaneous reading is added...

In a uni graduate seminar/project class we had access to firmware from
GM in order to build competition vehicles. But, being of the age I am,
this was long before the "veritable plethora" explosion of
microprocessors and the whole system was in one little M68HC11 and none
of the display functions currently were yet extant...

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