The 6.4 HD Hemi Thread

[HorseManAR]

Does a bed cover help any with fuel mileage? essentially removing that huge wind-catcher (tail-gate) at the back of the truck, just didn't know if adding a bed cover (or even a topper for that matter) would help with fuel mileage?

If so, that's an added bonus. I'm contemplating either a topper or bed cover.

Sud, I am as well. let me know what you decide on. I need something to cover up my entire bed that's lockable. I leave my fiver hitch and straps and such bacl there all the time.

 

[Donelam304]

Myth busters don't a story on this. I have need trying to find it and it's not coming up. But they tested running a truck in a stock configuration, tailgate down, and tonneau cover on. And all the testing they done, it showed that the tailgate down and tonneau cover on hurt the aerodynamics of the truck. That a stock truck got better gas mileage. If I find it, I'll post it. But I'm sure because I took the cover off my Silverado because of it. But it only made like a .4 mpg difference.

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[TWILLIAMS9]

Yeah the bed creates a pocket of air the circulates and causes the oncoming air passing over the truck to glide over the top of it.

 

[mowin]

I remember that episode. I was suprised at the results. Still see manufacturers ad's touting better fuel milage with a tonneau cover.

 

[Donelam304]

I remember that episode. I was suprised at the results. Still see manufacturers ad's touting better fuel milage with a tonneau cover.

I know. I was just looking at a couple of the manufacturer videos on YouTube. And they all claim to add milage.

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[tjfdesmo]

I was always under the impression that running with the gate down hurt MPG, but a tonneau or cap were basically a wash.

 

[arod412]

I remember that episide. One of the worse things was to either put the tailgate down or just remove it all together

 

[skHemi64]

My only dislike. I wish MDS would stay on longer. At least it should stay on when I am steady speed flat road. Could be it is still learning, since I only have 1100 miles on it.

 

[KTM]

Yeah the bed creates a pocket of air the circulates and causes the oncoming air passing over the truck to glide over the top of it.

Yup, I saw the same episode and was surprised too! Tailgate up is the best MPG I guess.

They also did the windows down vs AC on. It was roughly the same, maybe AC on might have been a little better if I remember correctly.

 

[NewBlackDak]

I haven't seen any measurable difference with the tonneau cover on. What I did notice immediately, is the side winds don't push you around as easily.


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[Donelam304]

I got one for y'all. One of the guys u work with bought a f250 4x4 when I bought my truck. He wanted different tires because his came with 245/70/17s. And he went to a 270/65/17. And on his way home he noticed a bad vibration. The tire place he got the tires checked the balancing of the new tires. They said they was good. And that it was his tonneau cover making the truck to vibrate. Lol.

Needless to say he took it to a dealership and it ended up being, the tire place screwed up to power coating on his rims and the bent 1 rim. Lol. And they didn't want to admit their wrong doing. Lol. But to blame it on the tonneau cover. Lol.

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[Caldwell]

hey fella's

has anyone had their 6.4L tuned yet with the new diablo support ?.

Also is it standard on the 6.4L to have " Active Air Management " built into the intakes ? if so I would assume just swapping a dry panel filter would make a slight improvement. Then to maybe take it one step further, has anyone thought about modifying the oem mid tube on the intake to smooth out the air flow into the throttle body ?. I would think there could be another small gain there without having to tune. from what I can see the oem mid tube does not have any intake baffles - is this correct ?

 

[ammo]

I'm waiting on ARH'S header to be released. Hopefully someone has a decent intake out by that time. Then I'll have to decide in either the Diablo or a Bully Dog custom tune.

 

[Rich]

New member. Just picked up my new 2500 CC with the 6.4. Ordered on April 29th. So far it's great. Will be used for daily driving and towing a 29 ft travel trailer. I'll post fuel mileage, etc if anyone cares.

 

[mowin]

New member. Just picked up my new 2500 CC with the 6.4. Ordered on April 29th. So far it's great. Will be used for daily driving and towing a 29 ft travel trailer. I'll post fuel mileage, etc if anyone cares.

Always like to hear what others are getting for milage while towing. And wheres the pic? You know the rules...

 

[TWILLIAMS9]

Going to the suspension shop to check out a 2500 CC getting the 8" lift and 37's to see what my truck will be like. I will take pics and post them up here once I'm done.

 

[TWILLIAMS9]

Here are the pics. For reference I am 6' 0" tall. The truck looks absolutely amazing! Can't wait to get mine done.



Rear 5" spacer


Front 8" spacer







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[SETEX 6.4]

Holy crap! So the door handles are even with your shoulders?
Nice.

 

[NewBlackDak]

I really don't understand 8" of lift, and getting no more travel out of it. They need some springs for that kit.


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[loveracing1988]

I really don't understand 8" of lift, and getting no more travel out of it. They need some springs for that kit.


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I would assume the cost of those bigger coils would double the cost of the lift itself.