'99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
i know i have at least 2 bad glow plugs its been 20 below wiland my fuel mileage dropped quit a bit so i take it this could be the culprit
By fuel burn to zero, he meant no-start.
The only impact bad GP's would have on fuel mileage is that the cyls with bad GP's wouldn't be burning the fuel injected as well as the others, but ONLY till the cylinders warmed up enough to fire correctly. Probably happens by the time you pull out of your driveway.
I'd think that other factors would have more to do with mileage than GP's, like whether you ate 3 strips of bacon instead of 2 that morning. AND the fact that your EBPV is staying closed longer at those temps.