6.4 Schooling

[BLKF250]

I got a 6.0 and now my dads looking into getting a truck ( hes got a dodge dakota which dont even get me started on) and he wants the 6.4 diesel but doesnt want bad gas milage with it. What are the Pros and Cons about the 6.4 i got him to go diesel soo iam just trying to get him set on the right motor.... He likes how quiet they are but doesnt like the fact they get 10 MPG. Any help would be awesome thanks..

[DavidPhillips]

I will be glad to certify that he will not get bad gas mileage with the 6.4.

It does not use gas


But your information seems to be inaccurate. Where did the 10 mpg figure come from?

If he is going from a Dodge Dakota to a Super Duty then I can't imagine him needing an F450. If he is getting a bigger truck then yes the bigger they are in general the more diesel they use. 10 still seems like a low figure.

I got 10.5 average mpg on the last 800 mile trip travelling North with a head wind from South Texas up through Corpus and on into Houston where I detoured through town for a while. No wind headed East through Baton Rough traffic and on to South Alabama.

I was towing my 30' #11,000lb 5th wheel at 65 to 70 mph. If it does 10 mpg empty something is bad wrong.

Empty I see from 18 to 20 mpg on long trips depending on how fast I drive. Around the house going into to town and running around I see 15 to 16 mpg.

[BLKF250]

lol sorry i meant diesel fuel not gas....its just what i heard people say about them because of the fuel demand and the way around better fuel milage is a DPF delete and a programmer and thats where you will see your fuel milage go up to about 20 or more

[orng1]

What;s the average you get without the trailer with the DPF still in there?

[08stroker250]

Originally Posted by DavidPhillips

I will be glad to certify that he will not get bad gas mileage with the 6.4.

It does not use gas


But your information seems to be inaccurate. Where did the 10 mpg figure come from?

If he is going from a Dodge Dakota to a Super Duty then I can't imagine him needing an F450. If he is getting a bigger truck then yes the bigger they are in general the more diesel they use. 10 still seems like a low figure.

I got 10.5 average mpg on the last 800 mile trip travelling North with a head wind from South Texas up through Corpus and on into Houston where I detoured through town for a while. No wind headed East through Baton Rough traffic and on to South Alabama.

I was towing my 30' #11,000lb 5th wheel at 65 to 70 mph. If it does 10 mpg empty something is bad wrong.

Empty I see from 18 to 20 mpg on long trips depending on how fast I drive. Around the house going into to town and running around I see 15 to 16 mpg.

I am gad you get 15-16 mpg in the city with your truck. When I had a DPF still on the truck, I was seeing 10-11 in the city and 15-17 on the highway

[08stroker250]

Originally Posted by BLKF250

lol sorry i meant diesel fuel not gas....its just what i heard people say about them because of the fuel demand and the way around better fuel milage is a DPF delete and a programmer and thats where you will see your fuel milage go up to about 20 or more

I reccommend Spartan, DPF/Cat delete pipe, and a S&B cold air intake That should get him good mileage and great power

[DavidPhillips]

Originally Posted by orng1

What;s the average you get without the trailer with the DPF still in there?

I drive the speed limit normally so that's 19 to 20 mpg at 65 to 70 on most interstates. However if I am pushing it or in a lot of traffic it drops my overall mpg to as low as 18. I usually average it out over an entire one way trip which varies from 800 to 1400 miles. These long internet trips will almost always net over 19 mpg minimum and it seems that it's mostly closer to 20 mpg.

While I see as much as 22 on some short runs it will not average that when regenerations are factored in. Also if you take off on a short trip and have a regeneration cycle it will not recover so your mileage is bad but not really a usable average. You have to drive through several cycles to get the average.

I have seen 8 mpg towing as well. Over the long average it will return to around 10.5 or higher. It depends on the trip. Types of stops and traffic driven through.


As far as city driving I don't do any really. If I leave my house it's 10 miles of interstate into town where I would drive down a boulevard or parkway and maybe some county roads to where I'm going. I have not been to NYC or any place like that to try it.

I normally see 15 to 16 mph around town. Normally it will drop in town and by the time I get home it's back up to 16.

[DavidPhillips]

Originally Posted by 08stroker250

I am gad you get 15-16 mpg in the city with your truck. When I had a DPF still on the truck, I was seeing 10-11 in the city and 15-17 on the highway

You can't compare city driving. Too many factors. Also I said town driving. It's just no way to compare unless you follow someone.


I believe it has a lot to do with the height, weight, gears, and tire size.

The other factor is the driver. Try different drivers in the same truck and the results will vary. We do this all the time at work.

I found that adding air to my tires also can give me a 1 to 2 mpg increase. Driving a good line as opposed to weaving around on the road or driving the hump over 1000 miles will make a difference of at least 1 mpg. I try to go 600 miles without stopping for best mpg. I can usually drive hundreds of miles without touching the brake or throttle. If I stop more I see a difference. Taking it easy on stops and restarts will help. I don't let the truck sit and idle.

The cruise control does well for me but It's possible for someone to out drive the cruise. A lot of people just pump the accelerator too much. Poor accelerator and brake control and traffic matching can reduce mpg.

I know a guy that has had two accelerator pumps changed in his work truck and my work truck has had none. They don't have cruise control and are both 2500's.

[DavidPhillips]

Originally Posted by BLKF250

I got a 6.0 and now my dads looking into getting a truck ( hes got a dodge dakota which dont even get me started on) and he wants the 6.4 diesel but doesnt want bad gas milage with it. What are the Pros and Cons about the 6.4 i got him to go diesel soo iam just trying to get him set on the right motor.... He likes how quiet they are but doesnt like the fact they get 10 MPG. Any help would be awesome thanks..

One thing I saw with mine when I first got it was the mpg was only 14 mpg at 75 mph. It was a lot better around 60 mph. As the truck breaks in it gets a lot better. Also the latest upgrades to the programming on the truck will improve regeneration cycles and make them barely noticeable.

I suggest you get 15,000 miles on the truck minimum before doing anything and see what you have.

I'm not saying that you should not mod the truck if that's what you want. I am saying you don't have to in order for the truck to work well. These trucks are well proven. A lot of oilfield companies, service companies, delivery, etc, etc, uses the most of them and they don't mod anything.

[Tarheel_6.4L]

Originally Posted by 08stroker250

I am gad you get 15-16 mpg in the city with your truck. When I had a DPF still on the truck, I was seeing 10-11 in the city and 15-17 on the highway

I'm seeing around the same as you are and I'm stock beside's the afe.