2016 Chevrolet Equinox- reflashing computer

can re-flashing a cars computer improve poor gas milelage if everything else is good? everything was checked at the dealer but my mechanic said reflashing can fix the issue.

How much has your MPG dropped since new?

I don’t see a software update or service bulletin to address fuel economy, ask your mechanic for the bulletin that he is referring to.

Fuel economy results are generally a factor of weather, driving conditions, speed, trip length and driving style.