And how many miles is on the ford VS Chevy? are we giving theese new diesels time to break in?

 

A little over 18K on the 6.4, and the mileage is not improving as I had hoped it would.

 

Just my $.02 but I think that what happened to SUVs (god i hate that term) is the same that is happening to diesel trucks. Back in the day people that wanted to hunt or fish or trail ride or work the farm bought them before we called them SUVs. You had your choice between capable trucks, Scout, bronco, K5 blazer, Ramcharger, Jeep (CJ, YJ,TJ), FJ all good light duty TRUCKS. Live axles, 4 wheel lo, easy to lift most offered a v8, manual hubs. All of a sudden they get popular and what the trucks are used for changes. Now only the jeep is left. People wanted better ride and lower ride height more cup holders and DVD systems the original use of the vehicle is long forgotten.

It is happening with Diesel pickups. The people that tow heavy or work their trucks are not the primary market for these trucks anymore. Why is off the line performance such an issue with these trucks? My friends old Dodge can pull a stump out of the ground but 0 to 60 I think you measure in minutes not seconds. He gets 20+ MPG at like 120K Miles. I think people that work there trucks would give up some performance for MPG and reliability. You can have high performance OR high reliability but very seldom do you get both. Perhaps they should offer a work truck version of the PSD and a performance version?

 

I have around 8,000 on mine and I'm getting 17 Highway MPG empty, Maybe something is wrong with yours, UNLESS, YOU HAVE A 450.

 

Ya if you have a 450 with 4.88's driving 70-75mph and your D-max is a lot lighter and has 3.73's. My 450 with 4.30's gets over 13 mty round town/rural driving. 8.726 towing 17k over 2,000 miles this summer driving over the speed limit. Maybe your computer is off too. Granted the D-max does get a little better mpg but something sound fishy here. My Firehawk will average over 20mpg at 80mph too.

 

As I am waiting for my new 6.4, I hooked up my fifth wheel to my 05 Dually with 4.10's and stored it for the winter. Pulling I got 9.5 mpg, and when I unloaded it I drove to Denver and my mileage wouldn't go above 12 mpg. So I think that the new 6.4 will be a LARGE improvement over what I currently own. Also Ford's are built heavier than GM's. For example... Ford has Solid Axle's GM doesn't. IMO go for what you like. Never base any decision on what others tell you, they don't always have the correct information or hard FACTS.

 

Yes, I have the F-450 with 4.88's. I would have rather have had the 4.30's but they weren't any available when I got mine. However, one of my best friends has the same truck with 4:30's and when towing he gets about the same mileage. We're towing about 16k pound boats, the same boat I was towing with the D-max. I usually drive the ford 75-80 mph and the chevy faster.
The last time I checked the Ford it was empty on a 250 mile highway run, running 80ish. The computer showed 8.8, however hand figuring came up with 8.
I agree the ford does seem to be a heavier built truck, but half the mileage doesn't seem right. However the D-max does have exhaust, breather and chip, since brand new.And it did increase the MPG, but it also has more power.

 

Its funny you mention that, i seen that JOB 2 trucks with SRW are now avaliable with a 3.55 rear end. I think that will help milage for the SRW guy's out there. Towing performance would not be as good, but it would be a good option for the primary daily driver guys.

 

Dont take this the wrong way, but this one of my compliants, if were comparing milage to other trucks they need to be apples to apples, not apples to oranges.

 

Originally I had 4.88's ordered but after reading the threads and learning I went with the 4.30's. If someone is going to be running 80mph with a truck you need get higher gears. You would have been better with a 350 3.73's. Running over 2,000 rpms with the 6.4 eats the fuel. At this point I would invest in a gear splitter that runs 500 rpms less on the top. But even with that you will still be over reving. Right now at 80 you must be running 3,000rpms? Even with 3.73's 80mph is about 2500rpms. Wow! From what I have heard that is why Ford is going to offer 3.55's with SRW for guys that want to run above 70 mph

 

I ordered a PSD F350 SRW for a daily driver, will sometimes tow a 10' dump trailer, I don't know much about the towing stuff but I did order 3.73 rears. Should I change to the 3.55 rears? please advise

 

3.55 would be the best for a dailer driver, if you tow something you'll just leave it in town/haul mode, the truck will do the rest. I don't know what the manual says about weight limits on the 3.55 gears, may want to ask the dealer to show you that.
I had 3.55's in a truck- could not keep it in OD, It had no guts at all in OD. Can't go wrong with 3.73's

 

I dont know the tow ratings for the 3.55 rear end, but i would check it out and if the tow capacity is within what you need, i would go for the 3.55 without a doubt.

 

I would love to have 3.37's, however I was trying to comply with my insurance. Which is why I went with the 450, ie, tow rating. I just don't understand why they don't offer a higher gear rating, I pulled the same boat with the D-max with 3.73's with no problems so I am sure the 6.4 would do just fine.
I have considered the gear splitter, but from what I have read they claim no increase in mileage on their website, there have been some questions as to how they will hold up under towing conditions, and I don't want to do anything that may effect my warranty, as I have already had to have the rearend and transfer case replaced. These are some serious concerns before I drop $4-5 grand with no guarantee it is going increase my mileage.