Horrible fuel mileage

[dsonyay]

Most of you guys with the mpg woes are likely driving a truck with the high gear ratios. I have a 4.11 rear end and if I drive at 2000 rpm on the hi-way (63mph) I can get about 17 to 18 mpg. My friend has the 3.78 (3.73?) and gets much better gas mileage than me at the same speeds (at 65 mph he's turning much lower rpms). At 2000 rpm he doing nearly 70mph.

My other buddy has 4.33 rear end on his 350 and his mileage sucks. He drives 70-75 on the hi-way and his rpms are way higher than mine. He doing a lot of boost too above 2000rpms and that does not help.

I think the owners manual advices trying to keep the revs under 2000 for best fuel economy. If you have 4.33 or higher, I bet you wouldn't be doing but 50mph at the that rpm level.

 

[MURR3061]

I wanted a new SD really bad, especially with the deals being offered on diesel trucks right now, but the fuel mileage reported by several owners has put the brakes on it for me. I love the looks of the new Super Duty Fords and was hopeful that the new 6.4 would be a more reliable engine than the 6.0s. I think the 6.4 is a better engine but the mileage is so poor that I've decided to stay with my ''05 Dodge Cummins. I bought the Dodge after several diesel guys talked me out of the problem-prone 6.0 Ford. I'll have to admit, the Dodge has been flawless. Zero problems with the 5.9 Cummins and nearly 14 mpg towing a 27ft Keystone Sprinter 5th wheel camper. I can get as high as 22 mpg empty on the interstate and get a constant 19.3 - 19-7 mpg in mixed city/highway driving around home. I just can't justify trading that for a new SD that gets 10 - 12 empty. I wonder if Ford knows how many sales they're losing due to this poor mileage! I've owned several Ford gassers over the years and they were all good vehicles. I would have bought a Ford SD in '05 except for the bad reports of reliability problems from several people. But I can't complain about the Dodge. It's never been back to the dealer for anything as I do my own oil and filter changes, air and fuel filters too. The inline 6 cylinder design too is proving to be a real benefit. There is plenty of room to work around the engine if need be. It almost reminds me of the old 300 ci six cylinder Ford truck that I used to own. Great truck and easy to work on. The Cummins reminds me of it a lot. As a long-time Ford guy (before '05 anyway), I'll give the SDs another look when they come out with the new Scorpion 6.7 diesel next year, but it's getting harder and harder to go back to Ford after owning this Dodge/Cummins for the last four years!

you know, i love ford a lot. i had an 08 ,but had a lot of problems, so i traded it for an 09 6 speed. it is a little better fuel wise, but that 5.9L is worth hanging on to in my opinion. i wish i would have bought used the first time in 08, but now it is what it is. the ford is sharp, i get complements all the time in it and it does go like a bat out of hell! well at least we are American proud right??? i am!!!!