Update 1: 2010 HD Fuel Economy Test

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The only rivalry in Michigan as intense as the one between the HD manufacturers is the spirited competition between the University of Michigan in Ann Arbor and Michigan State University in East Lansing. That’s why it made sense to drive the trucks between the two cities for our fuel economy challenge.

The trucks ran the approximately 150-mile circuit twice, for a total of around 300 miles, once unloaded and once towing a trailer. Tow/haul mode was used when the trucks were towing.

We started our test at the Pilot Truck Stop in Dexter, Mich. The same diesel and gasoline pumps were used for both loop fill-ups, with the same designated “filler” at the diesel and gasoline nozzles, using the same procedures and techniques.

Each truck’s fuel tank was filled to visual sight of liquid at or very near the top of the filler tube. Amounts of fuel were recorded, as well as odometer, tripometer and vehicle mpg computer information. All vehicles were reset at the beginning of the fuel economy test at the pump, and also reset at the end of the first loop at the same pump.

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Completed information is presented in two ways below. First, information from each truck is recorded in two charts from both loop 1 and loop 2. Second, vehicles are grouped by class (gas, SRW diesels, DRW diesels) and charted in head-to-head comparison format, both with and without trailers.

How rigorous were we with measuring our diesel fuel economy? We had techs from each of the manufacturers trigger manual service regenerations to clean out the trucks’ diesel particulate filters.

DPFs trap soot, a byproduct of diesel’s lean combustion process because not all of the fuel is burned. After a while, depending on workload and driving distance, the DPF becomes full and needs to be cleaned out, much like a self-cleaning oven. Extra diesel fuel is injected into the exhaust stream to boost temperatures in the DPF to more than 1,000 degrees, incinerating the trapped soot. That process can require up to six-tenths of a gallon of diesel – an amount large enough to impact our fuel economy measurements on a 300-mile drive. That’s why we started each truck with a clean DPF.

Mileage-2-560

We attempted to measure consumption of urea, or diesel exhaust fluid, for the first time. The harder a truck works, the more DEF that is consumed. At the Pilot station, it cost $2.99 a gallon at the pump and $5.99 a gallon by the bottle. Before we started our driving loop, we topped off the Ford and GM trucks – again, the Ram HD trucks are DEF-free – and measured their consumption at the end of both loops. For those interested in calculating their cost per mile, this new fluid addition must be included.

Total DEF measurements were conducted for the test, which included topping off at the beginning of the day, refilling at the end of the day and calculating usage.

Fuel economy and DEF consumption (where applicable) data is displayed below.

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Update #1 August-17-2010 10:29 am PDT: 
Thanks to a tip from commenter "Joe," we've updated the fuel economy commentary and tables below.

Unloaded and Loaded fuel economy calculations are unchanged from their original figures. Each took the distance traveled (miles) divided by fuel consumed (gallons) to calculate miles per gallon.

However, the combined fuel economy calculation that averaged the loaded and unloaded mpg calculations has been changed to an accurate formula that takes the total distance traveled during both legs and divides it by the total fuel consumed — the same way we calculated discrete unloaded and loaded fuel economy.

For example, using the old method of calculating combined fuel economy, the Chevy Silverado 6.0 achieved 14.10 mpg without a trailer and 10.16 mpg while towing and the average of those two figures was 12.13 mpg — an inaccurate way to calculate combined fuel economy. The new method takes the 318.41-mile total distance driven and divides it by 26.97 gallons (11.28 gallons unloaded + 15.69 gallons loaded) of fuel consumed to calculate an accurate figure of 11.81 mpg combined.

I regret the error and apologize that it will change the best combined fuel economy for the gas single-rear-wheel trucks from the Ram to the Silverado, and the diesel SRW trucks from the Silverado to the F-250. The diesel dual-rear-wheel trucks are unchanged. Again, it has no effect on the individual towing and unloaded mpg figures.

This update has no effect on how we scored the trucks, as the fuel economy score was based solely on how each truck performed in loaded and unloaded testing. Combined fuel economy was not a factor in the final score.

Again, thanks to Joe for spotting the inaccuracy and raising the question about it. This is one reason why we share all of the data we collect with our readers.

- Mike Levine

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For the three-quarter-ton gassers, the Chevrolet Silverado 6.0 was most fuel-efficient in combined driving, returning 11.81 mpg during the 300-mile drive, even though it never had the best fuel economy towing or unloaded. Unloaded, the Hemi-powered Ram 2500 returned a remarkable 15.04 mpg, likely due to its five-speed transmission and first overdrive that’s available in fourth gear, compared with fifth gear in the six-speed trucks. The Ford F-250 6.2 was the most efficient gas truck while trailering, averaging 10.86 mpg.

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The Ford F-250 6.7 diesel was the most fuel-efficient three-quarter-ton oil burner, edging out the Silverado by just .05 gallons during combined loaded and unloaded driving. The Chevy Silverado 2500 came closest of any truck to breaking the 20 mpg mark during unloaded driving, at 19.66 mpg. The Ford F-250 had the best fuel economy towing at 13.91 mpg.

Mileage-diesel-drw-rev

The Ford F-350 one-ton scored the best combined fuel economy number among the one-tons at 14.64 mpg. Without a trailer hanging off the back, the Sierra had the best fuel economy while the Super Duty was the most efficient of the three trucks pulling the six-ton trailer.

Amongst the three-quarter and one-ton diesels, the Ford trucks returned the best combined mileage even though the GM twins did best unloaded and the Super Duty's pulling.

Given how poorly the GMC Sierra 3500 Denali did relative to the three-quarter-ton Silverado under load and the F-350, we suspect it might have gone through regeneration when we were towing, even though we'd done a manual regen before the trip started. GM diesels can go a maximum of 750 miles before they have to regenerate their DPFs.

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Comments

So how does Ford say they have the best fuel comsumption, lol. Thanks Pickuptrucks.com, I'm excited.

GO CHEVY!!!

Just remember that this is before the "Job 2" Ford upgrade. The upgrade increases torque and allows the truck to hold gears longer without an upshift. Unfortunately the update wasn't available before the testing was completed.

Mike: By doing a manual regen, that skews the numbers up. A big part of any mileage test should be real world driving which includes regens while driving. I think it was a mistake to do that. Its useful to know what the best case senario is for each engine but particulary realistic. Also as a mechanic at a Dodge dealership, I can say that all Chryslers typicaly get lower fuel mileage untill 40-60k kms. Then they improve quite a bit. Anyone one know if GM or Ford does that?
Also was it yours or Chryslers decision to use a Mega Cab. Seems odd to me, because the heavier weight will affect mileage and acceleration.
So much for the myth that HEMIs just suck down fuel.
Excellent article.

They all should of have same odometer miles..

@Jordan: I'd agree if we'd driven the trucks in a 1,500 mile fuel economy test, which would have let the trucks regenerate at "natural" intervals. Unforunately, a regen can really skew the results during a short 300 mile loop. Having all the trucks start with clean DPFs was the best way to make sure the test was equivalent as possible.

@ Mike Levine Thats kind of my point. If one truck has to regen more than another then its real world mileage will be lower. Mileage was given a fairly significant weight in your overall scoring. Maybe with a real world test that could have affected the outcome of the standings. To late for that but maybe an idea in future shootouts. You posted a Motor Trend article between the SD and the Ram a while back and the mileage over the entire test was fairly even between the two.

@Jordan: Overall, we drove each of the trucks nearly 900 miles in a week. And they were driven in near identical conditions. I say that because we could have calculated fuel economy at the end of seven days but that wouldn't have been fair to all the trucks. Some towed trailers more than others over the course of the testing -- like running back and forth to Milford.

Maybe next time we'll make FE a 2-day event to boost the mileage to 1,000 miles (500 each day). Appreciate the feedback for sure! :-)

Gas trucks: Ram had the best mileage without a trailer and Ford had the best with a trailer.

The 3/4 tons were Chevy winning with 16.47 to Ford's 16.23 mpg combined. Is there really a winner when they are so close and mixed?

Diesel: Ford had better mpg with a trailer. Ford had better mileage with the 1 tons.

Again, no surprise that that isn't a clear winner in mpg.

It is no surprise the tightly wound rubber band GM used almost 5 times as much DEF as the Ford. No surprise as the harder a truck has to work, the more DEF is used. GM was forced to work harder and use up more DEF than the Ford. No surprise, folks.

Dan is trying to rationalize every category that Ford lost in, no surprise, no surprise....

Ford had the best MPG with a trailer in every test because well... I guess Ford's engineers thought that was more important in a work truck.

Where as the Duramax was consistently better MPG unloaded because well... GM's engineers expect people to use them as cars.

Looks like Obama builds a pretty good truck. Ironic, at best. Not interested in his products.

Dear All American,

In response to you asking how Ford bosts the best fuel economy. They do and they can. The one tonner beat Chevy hands down and Chevy beat Ford by less then 1/2 mpg in the 3/4 ton market.

@Patrick hahaha, i was thinking that

@ Mike -
I was surprising to see the big difference in DEF consumption between the GM 3/4 ton and Ford 3/4 ton diesels. The DEF rates were close between the 1 ton Ford and 1 ton GM.
Was that a typo? or a real world measurement?

If it is an actual number, did the GM engineers have any explanations for the difference in DEF consumption?

Ram showed 3 mpg difference from unloaded to towing, smallest MPG drop. Tells me the Cummins isn't working as hard when loaded. No wonder the Cummins last the longest. Way to go GM #1 HD diesel again.

It is no surprise the GM guys don't act rational like Dan. The GM guys just claim "superiority" in all tests without looking at the actual numbers of each. Maybe that is why GM does not own 50% of the heavy duty market. If you are towing a trailer, Ford Super Duty seemed to have the better mileage. If you are not towing, GM had the better mileage. But if you are not towing you could consider a F150 which is supposed to have the best in class mileage for 2011. GM used much more DEF, but don't tell a GM guy that, he just wants to claim victory with being rational and looking at the pros and cons.

Kudos to the Ram for doing very good without a trailer on regular gas.

But put a trailer on the Ram and it drops from 15 mpg way down to 9 mpg. This tells me the Ram needs major improvement when it is working hard with a load.

Kudos to Ford for having the best diesel fuel economy with trailers and the best combined 1 ton ton fuel economy.

@@ Mike -
I was surprising to see the big difference in DEF consumption between the GM 3/4 ton and Ford 3/4 ton diesels. The DEF rates were close between the 1 ton Ford and 1 ton GM.
Was that a typo? or a real world measurement?

If it is an actual number, did the GM engineers have any explanations for the difference in DEF consumption?

Sorry to repost - but I'm curious about the DEF consumption.

BEWARE pickuptrucks.com is all BS. they dont test the truck proper, and the trailer weights are light. pickuptrucks.com

Do gas-powered trucks have the same "DO NOT TOP UP" warning that modern gasoline cars have? There's fuel-vapour recovery equipment in the filler tubes that can get damaged if you "top up" the tank after the pump shuts off the first time.

These fuel economy averages are not calculated correctly for the 3/4-ton diesels. If you take the total miles traveled then divide by the total fuel consumed the ford gets better mileage. To simplify even further just add the total fuel consumed loaded and unloaded, both trucks drove the same distance, the ford burned less fuel how does that make the Chevy more fuel efficient.

@Joe: Thanks for the catch. You are correct and I've updated the combined fuel economy numbers to reflect the fix. I incorrectly averaged the two unloaded and loaded FE figures instead of taking the combined distance and dividing it by the combined fuel consumed. I regret the error.

This change has *no impact* on the separate loaded and unloaded FE calculations, as they are correct.

The commentary has been updated to reflect the change in best combined FE for the gas SRW trucks from Ram to Chevy and the diesel SRW trucks from Chevy to Ford.

This change has no impact on the final score, as it was calculated using only loaded and unloaded FE. Combined FE was not a factor.

As much as I hate to make a mistake like this, this is one of the reasons why we share so much data with our readers instead of only showing "black box" numbers.

Thank you, Mike, for your quick correction on mileage. I have a question you might be able to answer. What is the fuel tank size on the Ford 3/4-ton crew cab short bed diesel? I have received conflicting answers from different sources.
Thank you, Joe

@Joe: Again, sorry about that boneheaded calculation.

Looks like Ford has a wheelbase discrepancy that may be responsible for the discrepancy in fuel tank size. On the consumer site it lists two different wheelbases for the CC SB: 156-inch and 158-inch.

http://www.fordvehicles.com/trucks/superduty/specifications/capacities/ (158-inch)

http://www.fordvehicles.com/trucks/superduty/specifications/exterior/ (156-inch)

156-inch is 26 gallon, 158-inch is 37.5 gallons. I'll need to check with Ford on what the correct capacity is.

SO FUNNY HOW FORD GUYS TALKING ABOUT MPG :)

THE BEST MPG TRUCK IS CHEVY!
ITS HAS BEST MPG OVERALL!
BUYING A TRUCK YOU ALWAYS TOWING SOMETHING?
OVER 90% PICKUP DRIVERS DRIVE THEIR TRUCKS EMPTY/UNLOADED!!!!!!
AND CHEVY HERE IS WIN,BECAUSE HAVE A BETTER UNLOAD MPG!
BUT,WHEN TOWING THERE IS NO BIG DIFFERENCE FROM FORD!
DIESEL:
CHEVY 2500 SRW..................FORD F250 SRW
UNLOAD: 19.66.....................................18.55
TOWING: 13.28.....................................13.91

CHEVY 3500 DRW...................FORD F350 DRW
UNLOAD: 17.96.....................................17.32
TOWING: 11.04.....................................12.69

!!!CHEVY IS CLEAR WINNER HERE!!!

Hmmmm...the 3/4 ton diesel Ford burned 360mL or Urea, while the 3/4 ton diesel Chevy burned 1,750mL. The 1 ton Ford burned 2,650mL, while the 1 ton GMC burned 2,760mL of Urea...the 1 ton trucks burned very similar amounts of Urea, while the 3/4 ton trucks burned a highly different amount of Urea. Could it perhaps be a typo? With the Ford actually burning 1,360mL which would much better compare to the Chevy? Or does that Ford just "sip" Urea?

Looking at how much urea liquid the GM and Ford trucks used, and since the cost at the pump, I think it would be great to include this in a dollars/mile rating, since that is what really counts.
@Mike L: perhaps the next test could have a Dundee to Copper Harbor fuel Econ loop. That should put each truck trough a regen or two.

@Mr. knowitall: I did one calculation on DEF usage vs. fuel consumption for the Silverado 2500. It came out to be 2.3% of fuel consumed (1,750 ml = .4623 g / 20.1 g total fuel consumed over both legs). With DEF priced at $2.99 / g at the pump, that's $1.38 of DEF used.

Take Ram total fuel consumption (22.12 g * $3.25 / g = $71.89) and Chevy total fuel consumption (20.1 g * $3.25 = $65.33) plus add Chevy DEF ($1.38) and the GM diesel still has a fuel consumption advantage over the Ram.

By the way, GM says DEF consumption should be about 1.5% of fuel consumption.

I'm not convinced our measuring DEF was spot on, which is why is wasn't part of the scoring. There's a difference between trickling and pouring DEF into a tank.

that would look something like this:
GM 3/4t G $0.232
Ford 3/4t G $0.235
Ram 3/4t G $0.234
Gm 3/4t D $0.193
Ford 3/4t D $0.189
Ram 3/4t D $0.207
GM 1t D $0.225
Ford 1t D $0.210
Ram 1t D $0.236

Suppose it doesn't change the rankings, but it does point out that fuel savings alone would take over 200k to pay back on the GM, about 170k on the Ford, and over 300k on the Ram. I understand residual plays into the equation, as does the potential for greater pulling power of the diesels. But if the job can be done by a gasser, it's still cheaper to go that route. Given stable fuel prices, of course. If fuel goes back up to $5, the pay-back will happen much sooner, and you can make out nice on the residual.

@Mr Knowitall: By the way, I expect Ram HD pickups to switch to urea by 2012.

Last time fuel prices spiked, residual values tanked: http://www.pickuptrucks.com/html/news/sales/demand-and-trade-in-values-for-diesels-drop-dramatically-1.html

I was given the impression that Cummins was working on something that would not only keep them from needing urea but was gonna remove the need for particulate filters too. I don't know what the time frame was supposed to be though.

@Mike, I wonder when Dodge will stop running those "urea free" ads. I hope Dodge keeps the price sensible with the 2012 upgrade. $8,000 cheaper than Ford and GM! That's a big reason to go for the Dodge. If only the fuel economy was just as good!

i wished they would of test with in 500 miles diffence hell the chevys aint even broke in means less power and less mileage but all 3 trucks are good trucks just wished they would take in break in time for the motors it would of made a diffence in the end

The decision to keep a "level playing field" during the Trailer Tow portions by insisting all runs use "Tow/Haul Mode" might be counterproductive to realworld experiences.
Each Manufacturer programs different mods under the label "Tow/Haul", and all may not be required in a scenario such as you setup (low-profile trailer at max weight over flat terrain).
The Gas Ram HD would likely have performed better MPG in its test, as Ram Tow/Haul blocks both Overdrive and MDS - the latter provides a significant difference in MPG (even at freeway MPH) if it could have kicked in for even a few miles of your freeway trip.

Something to think about if your comparing gas engines to diesel engines in a HD truck and you drive as many miles per year as I do (40,000 plus miles per year). At this rate you will be out of warrenty in less than 3 years. The cost for repairs on the diesel powertrains is VERY expensive compared to gas due to the complicated systems used on diesel engines. And it doesn't matter which brand you choose. I have owned them all, and worn them all out. Gas engines today will give you good service far beyond 200,000 miles, and are MUCH LESS expensive to repair.

Also, todays diesel truck engines are designed to be driven hard and worked hard. If the majority of your driving is with 'No Load" and you choose the diesel powertrain, you can create problems with the engine sooner than if you worked it hard the majority of the time.

It seems to me that Ford is the overall winner. Heavy/Super Duty pick ups are all about carrying and towing heavy loads - why else buy one, might as well own a Prius and get real fuel economy. My trailer weighs in at about 12000 pounds, plus I carry another 1500 or 2000 on the truck - my F150HD 5.4 will pull it all but fuel economy drops to around 8 mpg sometimes lower and pulling a grade - well those trailer trucks just pass me by. Overall I city/highway loaded/unloaded [1500 # on truck minimum "unloaded"] I average 11.4 mpg [I really know the number, I calculate ever drop that goes in it] The bigger F350 Diesel just handles the load better and carries a little more and that makes towing less stressful. Also Fords select shift tranny is a real blessing when towing heavy loads as you can put it in a gear going up or down grade and keep her nice and steady without the tranny searching for the proper gear. Since my trucks are both work trucks and RV haulers creature comforts are high on my list. So far my choice has been Ford. When I try to get information from folks most just guess at their numbers or use the dashboard meters [always wrong and optimistic in my experience]. If you really want to know what kind of mileage you get, keep a log...



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