Better mpg

[Firefighter6567]

How can I get better fuel economy out of hemi 6.4? Only goes into eco mode downhill with foot off the gas. Thank you

 

[COAinPaso]

Best mpg is with the motor off . Seriously though, the best I can tell is these trucks will get 15-17 mpg cruising. Getting TO cruising speed (40-70+) is what kills that mpg. Even with a light foot on the gas. My max around town is probably 13, Highway 17 (once). But for the most part, the evic on mine shows 10.
As far as getting better mpg? Correct tire pressure, clean air filter, clean fluids...all the normal fuel economy tips should come into play and possibly help. Oh, my truck is pretty thirsty above 70 and has a full blown drinking problem at 80.

 

[bdc2]

My eco is overactive in town. So I just turn it off. The only time I run with it on is with the wind at my back. I have a 4.10. Right at 1950 rpm seems to be the sweet spot. Either side of it I lose mpg. It's not good. 14-14.5 into the wind a little better coming back. My eco didn't really get active until the truck hit 4000 miles.

 

[68PowerWagon]

Best I ever got was 20mpg on the highway. Most of the time in the summer (with summer blend) I average around 16. Winter time it's more like 11-12mpg. They are a 7,000lb brick so they are not going to get very good mileage. The MDS is nearly worthless. When it shuts down into 4 cylinder mode those 4 cylinders start drinking way more fuel than when it was using all 8 cylinders. The MDS is not really worth all of the technology that's in it.

 

[Firefighter6567]

Best mpg is with the motor off . Seriously though, the best I can tell is these trucks will get 15-17 mpg cruising. Getting TO cruising speed (40-70+) is what kills that mpg. Even with a light foot on the gas. My max around town is probably 13, Highway 17 (once). But for the most part, the evic on mine shows 10.
As far as getting better mpg? Correct tire pressure, clean air filter, clean fluids...all the normal fuel economy tips should come into play and possibly help. Oh, my truck is pretty thirsty above 70 and has a full blown drinking problem at 80.

 

[Firefighter6567]

If you call an engine a motor, stay out of my garage!!

 

[NewBlackDak]

Always travel down hill with a heavy wind at your back. I lost about .5 mpg going from my stock Firestone HT tires to the BFG AT KO II. You could prob get a little better with highway tread, and keeping them aired up.


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[Tim Garceau]

Trade-in for an 8 speed is a good start!

 

[COAinPaso]

My mistake (!!)


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[olyelr]

How can I get better fuel economy out of hemi 6.4? Only goes into eco mode downhill with foot off the gas. Thank you

You cant. It guzzles gas. Period. Nothing you can do about it. Put up with it or sell out.

FCA spends bazillions of $ on getting the best out of it, and they apparently think the mds is a worthwhile addition. If there was a couple hundred (or even couple thousand) dollar mod that would snake out a few more mpg’s, trust me, they would have sold em that way. They do stupid ****, but they would not overlook mpg’s.

 

[Black W900]

If you call an engine a motor, stay out of my garage!!

Do I have an engine in my motorcycle?
Then why do they call it a motorcycle?
They could call it an engincycle I suppose.
But that would be as stupid as your comment.

 

[mboymopar]

Do I have an engine in my motorcycle?
Then why do they call it a motorcycle?
They could call it an engincycle I suppose.
But that would be as stupid as your comment.

I think your onto something with the engincycle thing.
Motorboat would be an engine-boat.

 

[Blindsquirrel]

Nobody mentioned tow mirrors causing mpg robbing drag. Guess it’s just the cost of looking good?

 

[Statcher1]

I’ve noticed that running in tow/haul on the back roads actually improves my mileage. Atleast with my Cummins.

If you want to get really technical on the MPG gain. Run your tires at max PSI and fold your mirrors in while on the highway. Lol that should be good for another .5-1mpg


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[Nyramguy]

I actually dont think it's that bad for a big, heavy truck. It gets better mpg than my 03 Silverado with the 5.3.

 

[wgreggking]

Best mpg is with the motor off . Seriously though, the best I can tell is these trucks will get 15-17 mpg cruising. Getting TO cruising speed (40-70+) is what kills that mpg. Even with a light foot on the gas. My max around town is probably 13, Highway 17 (once). But for the most part, the evic on mine shows 10.
As far as getting better mpg? Correct tire pressure, clean air filter, clean fluids...all the normal fuel economy tips should come into play and possibly help. Oh, my truck is pretty thirsty above 70 and has a full blown drinking problem at 80.

Yeah it sucks gas ,when it was new it bothered me a little, dont look at the mpg gage very often. But it passes like a rocket, with a 3K trailer. Do like COA paso. The best way I save $$ is using the gas buddy app, sometimes save .30 or more per gallon, here in az, in ca even more.

 

[Marine Les]

I remember my old trucks, a 70 3/4t suburban and a 77 3/4 dodge w/400 MOTOR and they were very consistent as they always got 10mpg when not towing. I think a 3/4 HD truck with all the power the 6.4 has that gets 13/17 is pretty good. I still have my 2000 Cummins that gets 19/20 hwy not towing and costs more for its fuel and oil not to mention $5k more otd is considered good for its economy. If I replaced it the 6.4 with the 8spd is my choice over the new Cummins without question.

 

[olyelr]

I remember my old trucks, a 70 3/4t suburban and a 77 3/4 dodge w/400 MOTOR and they were very consistent as they always got 10mpg when not towing. I think a 3/4 HD truck with all the power the 6.4 has that gets 13/17 is pretty good. I still have my 2000 Cummins that gets 19/20 hwy not towing and costs more for its fuel and oil not to mention $5k more otd is considered good for its economy. If I replaced it the 6.4 with the 8spd is my choice over the new Cummins without question.

Actually, the cummins is a $9300 option.

 

[Rambojoe]

Someone stated that removing the 40 lb stock muffler and replacing it with a Mufflex or Solo piece was worth 1-2 mpg. I’m not sure how legit it is since we all drive them differently but I’m going to try it for the sound improvement anyway.

 

[Marine Les]

Actually, the cummins is a $9300 option.

In 2000 it was $5000.