Ultimate One-Ton HD Challenge: Fuel Economy

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We like doing dedicated fuel-economy runs on a real-world loop to give us an idea of how these pickups will work for consumers. We go to great lengths to find sizable routes that offer a good mix of city, highway, rural and congested driving so that we can deliver the most realistic overall mpg results.


At the end of our two separate drive loops (one done with a trailer and one without), all three one-ton turbo-diesels were close to one another when driven empty, with the Ram 3500 finishing just ahead of its two competitors with a calculated 16.31 mpg. The three were separated by less than 2 percent. However, with trailer in tow, the GMC Sierra 3500 did a much better job than the Ford F-350 or the Ram with a best fuel economy calculation of 7.76 mpg, which was more than 10 percent better than the Ford and 7 percent better than the Ram HD.

How We Did the Testing

Our home base for this Challenge was Ann Arbor, Mich., so our route wove through many cities and townships in and around the Detroit area. We topped off each pickup with fuel at the same gas station, using the same pump and same filling methods for each, allowing the pump mechanism to click off automatically the first time; then we'd manually fill with one more click after that.

We ran our 150-mile loop twice: once without trailers and once equipped with our 16,000-pound engineering trailers, which included a forward-facing 64-square-foot windscreen to replicate an average storage or camper trailer frontal surface area. We had three rotation spots on our route to change drivers (who were our judges) to make sure each pickup-and-trailer combination got the chance to moderate each driver's weight and driving habits.

Cars.com photos by Evan Sears


Ford F-350 Super Duty 6.7L V-8 Power Stroke TD

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GMC Sierra 3500 HD 6.6L V-8 Duramax TD

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Ram HD 3500 6.7L I-6 Cummins TD

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Overview | Milan Dragway | Fuel Economy | Milford Hill Climb | Milford Braking | Davis Dam | Davis Braking | Eisenhower Pass | Eisenhower Braking | Results



I am really surprised with how low the fuel economy was with all three. I have a motorhome on a Freightliner chassis that is 11 1/2' tall and 8 1/2' wide and weighs 25,000lbs by itself. I just did a 4,500 mile trip and averaged 11mpg. When pulling a three horse trailer the weight goes to 30,000lbs and the mileage drops to 9.9mpg. I only have 300hp and do slow down some going up hills but if that is the penalty for decent fuel economy I will take it.

What was the mileage of the DEF?

Such short test loops. I would like to see longer tests which include at least 1 DPF filter burn. Hard to compare data without knowing if one of the trucks went into a regen cycle or not.

From the results page: "the Ram's DEF usage was about two or three times worse than the others (counting our fill-ups, the GMC used 2 gallons, the Ford 3 gallons and the Ram 6.5 gallons.). "

Considering Ram used more than 3 X's as much DEF fluid than GM, Ram lost the economy round, big time!

Spam loses again!!

I do find it ironic that Ram used to advertise DEF free and now they suck up the most DEF

Fuel economy is a consideration for those who tow heavy despite the fact that the EPA doesn't require such numbers for HD trucks.

I think the FE number for all 3 trucks unloaded are pretty decent considering all the emissions equipment.

The EPA has ruined all the trucks. I had a 2005 Ram Dually with the Cummins 5.9 and it would 21 MPG empty not towing anything in town. On the road it would pull down 25 MPG with out a sweat. Towing my 24 foot closed car hauler it would get 17 MPG loaded.

The EPA can ruin anything.

wow, I didn't think diesels where suppose to drop so much when towing.

EPA makes them much cleaner than they used to be, but doesn't make sense that they burn more fuel to be cleaner. They tow a lot more, safer and faster that previous trucks. Don't know what you'd expect for mileage when you ad 16k of trailer and more air resistance?

Looking at these fuel economy figures, vs. the 3/4 Ton gas trucks, it doesn't seem like diesels are worth the extra cost anymore. The fuel economy is not that far off unloaded, only about 1 mpg better, maybe 2 if you throw in the DRW. Unfortunately, pickuptrucks.com didn't do a trailer towing test to see what that looked like, but I'm guessing the gas is not that far off. Diesels are getting less efficient with emission controls, and gas engines are getting more efficient.

Looks like ford is still using the 6.7 cummins in their f750.... It must be the best for longevity when hauling 30k + pounds or they would be using the powerstroke

The current 6.7L Cummins makes 18% more HP and 42% more Torque than the 2005 H.O. 5.9L Cummins. More power means more fuel consumption, plain and simple. So, going from 21 MPG to 16 MPG (in a heavier truck body wrapped around a heavier frame) nets you 42% more torque for giving up 24% in MPG. Seems like a good trade off if you need the capability of towing over 28,000 lbs. Therein lies the real reason for owning a modern diesel truck... the capability, not the economics. Gas powered trucks can't touch the tow ratings of diesel powered trucks. If you don't need to tow over 16,000 - 18,000 lbs you are better off sticking with a gas engine.

2005 Ram 3500 Quad Cab DRW 4X4
5.9 L H.O. Cummins
325 HP & 600 lb-ft
GVW 7358 lbs
GVWR 12,200 lbs
GCWR 23,000 lbs
Tow Rating 15,500 lbs

2014 Ram 3500 Crew Cab DRW 4X4
6.7 L Cummins
385 HP & 850 lb-ft
GVW 8568 lbs
GVWR 14,000 lbs
GCWR 37,500 lbs
Tow Rating 28,760 lbs

Yeah, the EPA ruins everything...

06 2500 5.9
A3k turbo
Efi tuning
Afe cai
60 hp injectors
Cat delete
Plus a few random goodies
585 hp 1403 tq at rear wheels
EPA can't ruin it if you don't let em

I don't get it, simply if we have 30% lower NOx emissions in our exhaust and burn 40% more fuel, we are actually increasing the amount of pollutants and using more none renewable resources. What gives???? I would rather spend less on fuel and have lower total emissions. It seems we have lost sight of the fact that we want to Reduce, Reuse and Recycle. The biggest impact would be use less fuel.

On the emissions debate. Burning more fuel no longer produces more pollutants. The pollutants burned are turned into much less harmful things regardless. If you burn one gallon of diesel all of the carbon emissions (like carbon monoxide and a few others) will go through the catalytic converter and be turned into CO2 AND H2O. if you burn 10 gallons of diesel the same exact thing happens except you will 10 times the amount of CO2 and H2O coming out of the tailpipe. Also the EGR and DEF systems together, reduce NOx to basically nothing, despite how much fuel you burn. DEF does a lot more than EGR to reduce NOx.

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