Gas Mileage- F350/F450/F550

I disagree on the fuel mileage thing, I want as good of mileage as possible and am willing to be a little slower if I get more fuel mileage. The 01 F350 I had must have had real high gears as I got 10-14mpg but the 07 F550 I think has 4.88's and I don't want to figure out what it's getting but it's turning ridiculous rpm on the highway. I am looking at changing the gearing to what my 350 had, they are towing the same stuff and I was satisfied with the 350's performance.

Gravel Rat said:

A F-450/550 with a 7.3 is only going to get at most 10-12mpg you will get 12 with a 6spd manual with the 4R100 automatic the enging revs higher.

If your looking at a 6.0 F-450/550 the tallest gear you can get is 4:30 I wouldn't go any taller than that.

A F-450 with 7.3 has the modified Dana 80 the tallest gear is 4:30 the F-550 has the S135 a expensive rear axle regearing it wouldn't make it worth the fuel savings most F-550s have 4:88 gears.

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Here's my deal, I want something more like the 3.73's. I think the 350 had them and I got 13-14 on long trips and 10-12 around town and towing. Why can't the 550 have higher gearing?

ToroLandscaper said:

How do you not care about fuel mileage? Gas cost money, and money is why we work, right? The difference between a couple of mpg's really adds up over the years.

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That's what I'm saying, the less I spend on fuel is more that stays in my pocket. When I switched from the 450(with 4.88's) to the 350(with 3.73's?) my fuel savings paid for the truck payment. The bad part was the 350 was always over loaded so that didn't work so well.

I don't think switching to the 4.30's from 4.88's will make enough difference. Diesel is already $3.00 a gallon which is not a good sign so I'm very interested to get all the mileage I can get.