Originally Posted by Gravel Rat
Your out of luck Ron, Ford never posted fuel mileage numbers for F-450-550 trucks I don't think the gov't requires it.
The F-450/550 trucks only come with two gear ratios 4:30 and 4:88, my F-450 has 4:88 gears open diff, it was spec'ed for towing a trailer.
You can find out what gear ratio your truck has their should be a white tag on the center chunk on the rear diff.
I went looking for that sticker last time I did my inspection and it's MIA.
Could I assume my fuel economy "might" be almost the same as a DuraMax?