6.4 Hemi ?

[drittal]

50% better fuel mileage??? Ha! Not seeing it. As I stated before, my father's 2012 got 12.5 empty new and had to spend 4k to get 16-17 out of it. Same trailer we are within 1mpg at same speeds.

[TDI-Minnie]

Not sure why your milage was that aweful, but my 2012 Cummins gets mid-low 20s empty on the highway and 15-16 towing my TT.

[drittal]

You are deleted then. The DPF system on the 6.7 until the introduction of DEF made them pigs. I test drove 3 in 2500's before settling on a new 6.4. None averaged more than 14 and change on the highway stock.

The old man is actually happy with 17 now, because that's better than his 24V did (15-16), towing it's about the same (9-10) but power is no comparison.

He went to the 24V from the V10 expecting double the mileage. Was a little perturbed he believed the hype and paid the expense to get the roughly the same towing mileage and 3 more mpg empty for about the same capability. So the wallet opened more for tuning and exhaust...then later 2 transmissions and both high pressure and low pressure fuel pumps when they went south...

To return 50% better mileage it needs to averase almost 30 empty at 72mph.

[TDI-Minnie]

I am, but it didn't make that big of a difference.
It depends on how you drive and NOT letting them sit at idle.

The DPF regeneration involves dumping fuel into the exhaust system to burn off the particulates and split the NOx. If you drive it the way it's intended, the regeneration cycles will be a lot less frequent and mpg improve.

The newer ones do the same thing except they consume ad-blue rather than diesel to break the NOx up into oxygen and nitrogen. Your fuel economy per mile may seem better but you use more DEF.

At what speed do you switch from the ECO 4-cylinder mode?? Speed limits around here are 70-75mph, so cruising at near 80 is normal.
I'm just not interested in tip-toeing the throttle to keep is running on 4. The odd sound and vibration is also irritating... had a rental like that a while back.

[1bigmess]

Originally Posted by TDI-Minnie

Your fuel economy per mile may seem better but you use more DEF.

I used to spend $24 to fill the DEF tank. Now I spend half that buying DEF in bulk at truck stops and pumping it into a five gallon jug to add a little later. Operating a diesel keeps getting cheaper as long as the price of fuel keeps going down as it has around here.

[TDI-Minnie]

How many miles can you get on a tank of DEF?

I'm curious because this is part of what's behind the VW cheating issue. They wanted to make the DEF last at least the oil change interval of 10k because consumers consider this a maintenance item.

[1bigmess]

Depends strictly on fuel mileage, which is all over the place between daily driving and towing. Page 2 of this FAQ: https://www.cumminsfiltration.com/pd...es/MB10033.pdf

[tuffr2]

Having towed with gasoline engines and now a turbo diesel I agree that the turbo diesel wins hands down. Especially out west where the elevations will rob non turbo gasoline engines of power at 3% per 1,000 feet.

I remember back in the 1980's. This car is going to cost more because it is a turbo. At trade in this car is not worth as much because it is a turbo.

I am hoping by 2010 the turbo is better manufactured and will last the life of the vehicle.

The gasoline direct injected eco-boost engine may be a game changer. Gasoline direct injected engines run cooler so maybe the turbo will last longer.

The OP is now into a cool (IMHO) philosophical discussion. Hope we are helping the OP.

[TDI-Minnie]

The #1 enemy of a turbo is heat and gassers run much hotter than diesels.
Especially important is how hot it still is when you shut it off and the oil starts cooking in the turbo.
Folks new to turbos would benefit from cool down timers, or there will be a lot of fried ecoboosts out there.

[drittal]

Dang this poor mileage. Cruise set to 72 with 3 stretches of 65mph construction zones and 60 speed limit into bismarck.

[Parks]

Originally Posted by drittal

Dang this poor mileage. Cruise set to 72 with 3 stretches of 65mph construction zones and 60 speed limit into bismarck.

Ha! Drittal, nice to see you over here from RF. Im Skrap over there. Like that 23mpg. Best i got was 18.2 but had about 1000lbs of people and gear on last road trip and causing at about 79mph.

[drittal]

Sup, dood? 18.2 at 79 is Rollin on down the highway.

People who have never tried the 6.4 just write it off as getting 12 because it doesn't burn oil or because their buddy's 8yr old 6.0 only gets that mileage.

I had 2 ecoboost f150 and my father in law has one. The only one that did better mileage wise was the one with 3.31 gears.

[drittal]

Originally Posted by TDI-Minnie

The #1 enemy of a turbo is heat and gassers run much hotter than diesels.
Especially important is how hot it still is when you shut it off and the oil starts cooking in the turbo.
Folks new to turbos would benefit from cool down timers, or there will be a lot of fried ecoboosts out there.

the ecoboost turbos are resistant to coking. It uses water cooled turbos, instead of oil. An oil cooled turbo can fry the oil meant to cool it if shut down while hot. The ecoboost uses passive thermal syphoning that will continue to circulate water through the turbo for cooling even after engine shutdown.

[Don_T]

Originally Posted by drittal

Sup, dood? 18.2 at 79 is Rollin on down the highway.

People who have never tried the 6.4 just write it off as getting 12 because it doesn't burn oil or because their buddy's 8yr old 6.0 only gets that mileage.

I had 2 ecoboost f150 and my father in law has one. The only one that did better mileage wise was the one with 3.31 gears.

The 2014 Ram 2500 regular cab 6.4, 3.73 axle I had didn't do real well on gas. Empty with the cruise set at 65, at sea level, flat ground, I got 15 MPG. Pulling my 8k TT I got about 8 MPG.