3/4 ton fuel economy?

plainjaneFJC

Deplorable
I recently got into a diesel truck from a 6.0 gas (which got terrible gas mileage). My "new" to me truck is a 2002 2500HD, 6.6 duramax with 90k miles. I am pleasantly surprised with the fuel mileage, I have been averaging 20-23 MPG unloaded at 60-70 mph highway driving, high teen mpg in town driving.

I tow cars intermittently and haul firewood, which is the real reason for the truck, but now I'm considering trying to take it on a trip/mild off road and see how it does. Diesel in my area is usually 12-20 cents more than regular unleaded. And my jeep grand Cherokee with the lift and tires is only getting 16 MPG....

You are on borrowed time with the LB7s injectors, I've been thru it. The injectors and the t-case rub got me on that truck.
 

vintageracer

To Infinity and Beyond!
I can comment on the 3 different generations of Dodge Cummins Diesel equipped trucks and 1 first year 1995 Powerstroke Diesel equipped truck I currently own. This is real world MPG'S noted by logging the miles, gallons and cost of fuel in a log book for all the trucks.

1993 First Gen Dodge Ram 250 4WD extended cab long bed stock 12 valve mechanical injection Cummins and an automatic transmission. Consistently gets 20 MPG local driving riding around. MPG goes up several MPG on the road 70 MPH. 3.54 Gears. Drive 55 MPH and you can get into the mid 20's on MPG. No hitch so no information concerning towing with this truck. 201K Miles

2001 Second Generation Dodge Ram 250 2WD extended cab long bed stock 24 Valve Cummins with automatic transmission. Consistent 22 MPG around town, mid 20's on the road going 70. 3.54 Gears. 16-18 MPG pulling 1 car trailer and 15 MPG pulling 2 car tag trailer. 270K miles

2003 Third Genreation Dodge 350 2WD crew cab long bed stock 24 valve cummins with 6 speed transmission. Consistent 22 MPG around town, mid 20's on the road going 70 and I have seen 28 MPG driving 55-60 MPH. 3.73 Gears. 18-20 pulling 1 car trailer and 16-17 MPG with the 2 car tag trailer. 190K miles

1995 Ford F350 2WD crew cab extended cab Centurion stretch stock Power Stroke with Automatic transmission. Only 1 or the 4 trucks I bought new. 12-14 MPG all the time with or without a trailer running 55 or 75 MPH. 4.10 Gears. I have every gallon of fuel and mileage noted from new in a log book on this truck. 204K Miles

REAL WORLD MPG's for the above trucks referenced above!
 
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vintageracer

To Infinity and Beyond!
My understanding is the govt or oil companies got involved in the early 2000's because truckers and the rail system were throwing fits at the constantly changing prices, making it hard for them to bid jobs accurately or forecast their potential earnings for a given quarter. They said, essentially, "you want a more consistent price, okay, here!" and set the prices a lot higher to cover their own butts, and it's been higher ever since.

Yes it's the oil companies however not for the reasons you think.

It's refining capacity that's the issue.

Although diesel is at the "bottom" of the refining process when making gasoline the refineries have become very good at "De-Bottle-necking" the production process since there has NOT been 1 new refinery built in the USA in over 40 years. Nobody wants one in their backyard. As such we in the USA are great at making gasoline which powers the vast majority of vehicles on the road in the USA with the "De-Bottle-necking process leaving far less downstream feed-stock for diesel fuel production.

In Europe the situation is reversed as there are more far diesel powered vehicles on the road than gasoline powered vehicles. As such the Europeans are primary in diesel fuel production and not gasoline refining.

You may remember some gasoline shortages in the USA in 2005, 2008, 2012 and 2014 due to hurricanes, storms and refinery shutdowns. Many folks just said just go import refined gasoline from Europe of other parts of the world. It's not that simple as other parts of the world did not have any gasoline supply to sell as they were not primary in gasoline refining. They were primary in diesel fuel refining.

This is why diesel now costs more than gasoline. There's so much less refining capacity for diesel fuel in the USA than many years ago when diesel was cheaper than gas when our gasoline refining process's were not near as efficient therefore providing far more feed stock for diesel fuel production.

Personally "I" think the price difference between gas and diesel will grow as the diesel vehicle market for retail consumers is shrinking as fewer and fewer diesel powered vehicles are available for retail consumer purchase (cars and small trucks). Add in the SIGNIFICANT premium charged by the OEM manufacturers for the diesel engine option and it's pretty clear that the OEM's are far more interested in "Direct Injected" gasoline engine technology and Electric vehicle technology than diesel fueled vehicles for the retail consumer market. Let's not forget that gasoline and electric vehicles much more manageable and attainable emissions standards than do diesel fueled vehicles.

The is the exact reason why Kubota NO longer imports their 30HP diesel engine for small tractors and lawn mowers. That particular engine cannot meet the emissions diesel engine emissions standards and Kubota is not interested spending the money needed to make that engine emissions compliant.

And you "thought" is was all about the price of oil!
 
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Laps

Active member
2002 Dodge Ram with 3.54 rear, diesel, 2500, manual: 16-18 MPG around town, 22-25 MPG highway

2012 Dodge Ram with 3.42 rear, diesel, 3500 SRW, automatic: 15-16 MPG around town, 19-21 MPG highway
 

dmoo

New member
Yeah, cool, great to see another 6.6 Duramax owner with similar results. Same experience with my previous van, too, which was a '98 6.5 Duramax. As for getting off the pavement, I've had both my Duramax's off-road, though never on highly technical trails or rock-crawling. Plenty of "4wd or high-clearance only" type roads in the SW desert lands, though, always without problem. I've never had a problem with rwd only in these vans in severe winter conditions, either. That said, though, I'm itching to get a 4x4 conversion so I can go further back-country and do a lot more off-grid with greater peace of mind. Picking up a new XV-2 trailer this week to tow behind and use as base camp, too, and having 4x4 will allow me to haul it further back-counry

I need to experiment with the 4x4 system and get used to the size compared to the jeep.

You are on borrowed time with the LB7s injectors, I've been thru it. The injectors and the t-case rub got me on that truck.

unfortunately I know, I have already started putting money aside for the repairs when they come up.
 

Roaddude

Long time off-grid vanlife adventurist
Yes it's the oil companies however not for the reasons you think.

It's refining capacity that's the issue.

. . .

And you "thought" is was all about the price of oil!

Ahh, all very interesting, Mike, thanks for the add'l info.
 

longball

New member
I need to experiment with the 4x4 system and get used to the size compared to the jeep.



unfortunately I know, I have already started putting money aside for the repairs when they come up.

Good idea, stick with it. My 2004 LB7 hit 198,000 miles last week. The first set of injectors were replaced at 142k miles. I added a Niktane fuel filter adapter (3 micron Baldwin filter) at the same time and additive has been added to every fill up since then. In spite of all that they'll still probably have to be replaced again soon.


Sent from my iPhone using Tapatalk
 

TwinStick

Explorer
2008 Dodge Power Wagon, 5.7L Hemi, 345 hp & 375 ft lbs, 4.56 gears, G-56 manual trans. 8-10 mpg empty or towing our 2016 3500 lb camper. Don't seem to matter much. Have gotten as little as 2-3 mpg when towing our old 2005 10,500 lb Toy Hauler up long steep grades. My overhead computer is dead accurate. I have hand calculated many, many, many times. It is always the same as what the overhead computer says. I swear that when I press the mpg display---I hear laughter !!! LOL I usually tell people that when you hear the words 3/4 ton & gasoline engine it is usually followed by 10-14 mpg or less. LOL
 

Regcabguy

Oil eater.
2007 5.9 4wd,G-56 w/3.73's. The final drive with my G-56 yields the same effective ratio as an auto w/4.10's.
I'm always reaching for a 7th gear. My Northstar's been on the truck since Oct. 06. I average 13-14 mpg city and a couple more on the highway.
EFI Live and 35's. Bat out of hell in the power dept.
The few times I've dismounted the camper I immediately see an increase of 3+mpg.
My 24v,DTT trans,285's and 3.54's yielded the same mpg. That one without the camper would net 20mpg freeway.
I rode in a 2012 F-250 with a shell and contractor rack with a roof mounted tent. Carli suspension,6.2 V-8. Decent power.
The dash readout said 8mpg.
 
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MT6bt

Rock hound
I have a 98 12 valve and when I aim for maximum fuel economy, usually see between 21-22 mpg. This is with 265/75/16 A/T tires, 3.54 gear ratio, with fairly mountainous terrain (I live in montana) traveling 65 mph.
I've been running 35x11.2x18 for several years now with a bull bar, small lift kit, and usually loaded up with at least 1000 lbs of gear/people/dogs and regularly can see around 18-20 doing 65-75.
Last year when I took a road trip out to Olympic forest, I was driving around the area with an alaskan camper, 3 people, 2 dogs, a hitch haul on front with a spare tire and lots of gear... well over GVWR, and was baffled to see 17-18 mpg! I think it was the combination of doing 55 mph, low altitude, and good weather that attributed to this. This was over a couple fill ups and several hundred miles. The rest of the trip which included many, many mountain passes, I still managed to see numbers above 15 mpg, with one fill up Slightly below that mark due to high speed Traveling.
Pretty amazed how economical the ole 12er is.

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Arktisk

New member
Anyone have solid input on 5.3 chevy/gm? Figure most folks will have some sort of lift or whatever going on.

I am sort of in the market but do not want to kill the fuel budget in jumping from import to domestic fullsize.
 

Littlehouse

Adventurer
2008 crew cab short bed with the 5.3, 124k miles, 33's, and a 2.5" level. Getting between 11-12mpg, but it's probably 95% stop and go driving. Newer models will have the 6/8 speed tranny, and get better mpg.
Edit: This is with 3.73 gears as well
 
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TCICapn

Member
Hey Mikekey are you still on the stock 4.10 gears now with 37s? If so 15mpg (I assume mostly highway cruising) is pretty good! Fine looking truck btw! Maybe someday I'll have a power wagon too...
 

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