Here Are The Diesel Truck Miles Per Gallon (MPG)
The MPG of Diesel Trucks Largely Unknown. And, Varies Greatly Based on a Number of Factors
The miles per gallon of diesel trucks is anyone’s guess.
Vast sums of Information is available with respect to the MPG of passenger light-duty trucks. The Environmental Protection Agency has policies in place to ensure vehicle manufacturers test cars and light-duty trucks and publish the findings. The same information is not available for the mpg of medium and heavy-duty trucks.
Currently, there are no EPA fuel efficiency and emissions standards for medium, heavy, and super-heavy-duty trucks. With no EPA standards, there is little incentive for vehicle manufacturers to publish the results of heavy-duty truck MPG tests. So, the public does not see the findings of manufacturers’ tests of vehicles over 8,500 gross pounds.
According to President Obama, “Heavy-duty trucks account for just 4% of all the vehicles on the highway. [But,] heavy-duty trucks are responsible for about 20% of carbon pollution in the transportation sector.” In a 2014 speech, Obama explained. “[Heavy-duty trucks] haul about 70% of all domestic freight.”
Emphasizing the significance, “70% of the stuff we use, everything from flat-screen TVs to diapers to produce to you name it,” he said.
“Every mile that we gain in fuel efficiency is worth thousands of dollars of savings every year.”
New Diesel Truck MPG Standards for 2024
Following his speech, Obama set major changes in motion with respect to medium and large duty trucks. One change he made was the implementation of MPG and emissions standards for medium and heavy-duty trucks. The steps Obama took to begin the process are now coming to fruition.
In a late 2017 EPA website publication, the agency made it clear that the plan is nearly complete. “The EPA and NHTSA, on behalf of the Department of Transportation, are finalizing rules to establish a comprehensive Heavy-Duty Truck National Program.”
In the post, the EPA makes the specifics of the policy rules clear:
“The U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration jointly published the second phase of greenhouse gas (GHG) emissions and fuel efficiency standards for medium- and heavy-duty engines and vehicles through their authorities under the Clean Air Act (CAA) and the Energy Independence and Security Act of 2007 (P.L. 110-140).”
In the future, manufacturers of heavy-duty vehicles must test their vehicles’ MPG and emissions and publish the findings. But, medium, heavy, and super-heavy-duty truck manufacturers will not have to do so until 2024. Until then, determining the MPG of specific diesel truck makes requires a large degree of estimation. But, there are a number of knowns with respect to diesel fuel and diesel engines.
The factors that determine diesel truck MPG are not a secret, even if the MPG and emissions of medium and heavy-duty trucks are. In the meantime, an understanding of the factors that determine diesel truck MPG will have to suffice.
Factors that determine diesel truck MPG
The miles per gallon (MPG) of diesel trucks depend on a variety of factors. The mileage on, and age, of a diesel engine, play a large role in MPG. The weight of the truck and the weight of a load also influence MPG significantly.
Additionally, the technologies supplementing a diesel engine play a disproportionately large role in the miles per gallon of a diesel truck.
There are a large number of minor factors that influence fuel economy in a major way The Cummings’ MPG guide is an explanation of the physics of MPG. Aerodynamic drag, engine operation and maintenance, vehicle operating techniques, and weather and seasonal conditional all play a role in the MPG of a diesel truck.
But, age, weight, and technology play the biggest roles in MPG.
Classes of Diesel Trucks: Pickup Trucks Versus Three-Axle Trucks Versus Four-Axle and Trailing-Axle Trucks
Again, the EPA and FHA only require data and statistics on the MPG and emissions of trucks less than 8,500 lbs. The way the EPA and FHA rules are written means truck manufacturers are exempt from providing MPG and emissions statistics for seven classes.
There is a direct correlation between the size of a truck — the weight specifically — and the diesel truck’s miles per gallon (MPG.) The bigger the truck, the less fuel efficient it will typically be. As such, understanding truck sizes go a long way in understanding truck fuel mileage.
Truck class-types are generally determined by weight and the number count.
Making generalizations about the MPG of diesel trucks requires an understanding of diesel trucks class-types. The Federal Highway Administration divides highway-legal trucks into eight (8) classes.
Only eight are legal to drive on federal highways, however. And, the majority of diesel trucks in the United States fall within seven classes.
Class 1 and 2 Light-Duty Trucks
The vast majority of Class 1 and 2 Light-duty trucks are gasoline powered. Class 1 light-duty trucks are those that weigh less than three tons (6,000 lbs). Those light-duty trucks that are in the Class 2 category are between three and five tons (6,000 – 10,000 lbs.) While there are some diesel Class 2 light-duty trucks, the majority are also gasoline.
Class 3 Medium-Duty Trucks
Class 3 medium-duty trucks, on the other hand, are primarily diesel trucks. The Ford F-350 “Super Duty”, Ram 3500, and Silverado 2500 are examples of Class 3 medium-duty trucks. Class 3 diesel trucks are among the lightest diesel trucks and, therefore, get some of the best diesel fuel economies.
However, since Class 3 medium-duty trucks weigh between 10,000 and 14,000 lbs, manufacturers are not required to provide the public with MPG statistics nor emissions data.
According to Fuelly.com members, the norm mpg for a 2000 F-350 V8 diesel is around 13 gallons. Those F-350 diesel engines produced from 2012 to 2017 get — again — roughly 13 mpg. For a 2000 Ram V6 3500, the norm is 15 miles per gallon according to Fuelly members. But, Ram V6 3500 engines produced from 2007 – 2010 get 13 mpg. Chevy Silverado 3500 HDs manufactured between 2008 and 2017 all get between 12 and 14 mpg.
If the more than 200 Fuelly members who reported statistics on these three class 3 diesel trucks provided legitimate data, it is safe to say a U.S. made class 3 medium-duty truck between 10,000 and 14,000 lbs manufactured between 2000 and 2017 will get around 13 miles per gallon.
Class 4 Medium-Duty Trucks
Class 4 trucks are the smallest in the medium-duty truck category. This class is primarily a diesel engine class. Class 4 trucks include the F-450 and Ram and Chevy 4500. These trucks are in the seven-to-eight ton range (14,000 to 16,000 lbs.)
According to CarandDriver.com, the 2017 F-450 gets a “thirsty” 13 miles per gallon. Fuelly.com members report that the 2000 – 2008 models get closer to 10 mpg. The same was reported for the Dodge Ram 4500 for the years of 2008 and 2009. A 2012 Chevrolet 4500 gets 9.8 according to a member who did 73 fill-ups.
Again, these are field tests taken by amateur truck enthusiasts, but if correct, a U.S. made class 4 medium-duty diesel truck gets between 9 and 11 mpg.
Class 5 Medium-Duty Trucks
Class 5 Medium-duty trucks weigh roughly 8 to 10 tons. International has the Terrastar, Ford has the F-550, Chevy the 5500, and GMC as well. Class 5 trucks weigh roughly between eight and 10 tons (16,000 – 19,500.)
A Fuelly member who filled-up 178 times got 8.4 mpg in a Chevrolet 5500. The Dodge Ram 5500, years 2012 through 2016, gets around 8 mpg, though one member who did 292 full-ups only gets 7.2 mpg. Thirty-nine Fuelly members found that F-550 trucks made between 2000 and 2016 get nine miles per gallon.
The U.S. manufactured class five trucks, if Fuelly members are correct, get around 8 miles per gallon.
Class 6 Medium-Duty Trucks
Class 6 trucks include the International Durastar, the Chevrolet Kodiak, and the F-650. These trucks weigh between 19,500 and 26,000 pounds.
Fuelly member report that the F-650, if manufactured between 2004 and 2015, get about 7.5 miles per gallon. Those International Durastars made between 2000 and 2016 get 8 mpg. The Kodiak gets 8.4 according to an owner who took data from 178 fill-ups.
Class 7 Heavy-Duty and Class 8 Special-Duty Trucks
Any vehicle that weighs between 26,000 and 33,000 pounds is a class 7 heavy-duty truck. Anything heavier is a class 8. Class 7 trucks include semis and dump trucks. Class 8 trucks are called super-duty or “special-duty” meaning they take special exempt heavy and wide loads. Additionally, special-duty trucks typically have four or more axles.
Some older three-axle dump trucks get less than 5 miles per gallon. The MPG of late-model three-axle dump trucks is around 6.5 miles per gallon according to Equipment World.
Class 8 super-duty trucks consume even more fuel. The fuel economy of four-axle and trailing-axle trucks is measured in hours, not MPG. Some mining trucks are so large that in a single day they use 60 gallons of fuel.
Diesel Truck Weight and MPG Mileage
According to a VTT Technical Research Centre of Finland study, a 60-ton truck uses almost 33% more fuel than a 42-ton truck. That means a construction, development, and/or mining company can use tens of thousands of fuel each year.
Cutting fuel costs, as a result, can mean massive savings. The Rentar Fuel Catalyst is guaranteed to pay for itself in less than a year. By improving the fuel efficiency of a diesel engine by 3% to 8%, the Rentar will produce an ROI in 9 to 12 months or less in most cases depending on mileage is driven and fuel prices. And, the Rentar comes with a 10-year warranty.