Diesel trucks are renowned for their power and durability, but fuel efficiency is also a crucial factor for owners. While heavy-duty diesel trucks aren’t subject to mandatory EPA mileage ratings like light-duty vehicles, understanding how to optimize your Diesel Truck Fuel Mileage is essential for saving money and reducing environmental impact. This guide dives into the factors affecting fuel economy in diesel trucks and how you can improve it.
Understanding Diesel Truck Fuel Economy
For light-duty trucks and cars, the Environmental Protection Agency (EPA) mandates fuel economy estimates. These mpg figures are readily available on window stickers at dealerships and in online vehicle reviews. Historically, light-duty pickups equipped with smaller versions of the Cummins, Powerstroke, and Duramax diesel engines were leaders in fuel economy.
However, diesel engine options in light-duty trucks have become less common. Heavy-duty (HD) trucks, with a gross vehicle weight rating exceeding 8,500 pounds, are exempt from these reporting requirements, making it harder to directly compare their mileage.
Despite the lack of official ratings for HD trucks, real-world data and tests provide valuable insights into diesel truck fuel mileage.
Key Factors Affecting Diesel Truck MPG
Several elements influence the fuel economy of your diesel truck:
- Vehicle Weight: Heavier trucks inherently require more fuel to move.
- Vehicle Condition: Regular maintenance is vital. Neglecting upkeep can significantly reduce fuel efficiency.
- Vehicle Age: Older trucks may experience wear and tear that impacts fuel economy.
- Stock vs. Modifications: Aftermarket modifications, especially performance-enhancing parts, can alter fuel consumption.
- Driving Habits and Conditions: How and where you drive plays a significant role. Aggressive driving and stop-and-go traffic decrease MPG.
Upgrading your truck with aftermarket diesel parts from reputable suppliers like ProSource Diesel can be a strategic way to enhance fuel economy. These parts are designed to improve airflow and optimize fuel delivery for greater efficiency. Furthermore, consistent maintenance and mindful driving habits are crucial for maximizing your diesel truck fuel mileage.
In ideal conditions, without towing or heavy loads, a diesel truck can achieve upwards of 20 mpg on the highway.
Diesel vs. Gas HD Trucks: Fuel Economy Comparison
While HD truck manufacturers don’t publish EPA fuel economy ratings, independent organizations like Consumer Reports and Car and Driver conduct real-world tests to gather data. Generally, due to their increased weight, HD diesel trucks tend to have slightly lower mpg—often 1-2 mpg less—than comparable gasoline-powered HD trucks.
Heavy-Duty Diesel Truck MPG Ratings: Top Performers
Here’s a look at some heavy-duty diesel trucks and their real-world fuel mileage averages:
#5) Chevy Silverado 2500 HD – 14.3 MPG
The Chevy Silverado 2500 HD, along with its GMC Sierra 2500 HD counterpart, utilizes a robust 6.6-liter V8 Duramax diesel engine paired with a 10-speed automatic transmission. Car and Driver’s testing indicates 18 mpg in city driving and 21 mpg on the highway for the diesel Silverado 2500HD.
However, real-world owner data from Fuelly suggests a combined average of 14.3 mpg for the 2024 Chevy Silverado 2500 HD with the 6.6L Duramax V8 diesel. This highlights the difference between controlled testing and typical driving conditions.
#4) RAM 2500 – 15.9 MPG
The RAM 2500 boasts a powerful turbocharged 6.7-liter Cummins diesel engine, known for its impressive torque. Current models are reported to achieve 19 mpg in the city and 24 mpg on the highway in testing scenarios.
Fuelly’s data, reflecting real-world driving, shows the RAM 2500 with the 6.7 Cummins diesel engine achieving an average of 15.9 mpg for the 2023 model, tying with the Ford F-250 for diesel truck fuel mileage in this category.
#3) Ford F-250 Super Duty – 16.1 MPG
The Ford F-250 Super Duty is equipped with a turbocharged 6.7-liter Powerstroke V8 diesel engine, making it a formidable work truck with substantial horsepower and torque. Car and Driver’s evaluations report 20 mpg on the highway and an overall average of 15 mpg.
Recent data from Fuelly for the 2023 Ford F-250 Powerstroke 6.7L diesel indicates a real-world average of 16.1 mpg. This figure underscores the slightly higher fuel efficiency observed in real-world use compared to lab-controlled tests for this model.
Light-Duty Diesel Truck MPG Ratings: Efficient Options
While diesel engines are less prevalent in modern light-duty trucks, some previous models offered excellent fuel economy. GM discontinued the Duramax I4 engine in the GMC Canyon in 2022, and Ford no longer offers a Powerstroke diesel option for the F-150.
However, let’s look at the fuel mileage leaders in the light-duty diesel truck segment:
#2) Ram 1500 EcoDiesel – 22.1 MPG
Ram discontinued the EcoDiesel engine for the 1500 model line in January 2024. The last diesel option was the 3.0-liter V-6 EcoDiesel, available in the 2023 Ram 1500.
According to fueleconomy.gov, diesel-powered Ram 1500 models were estimated at 21 mpg city and 29 mpg highway, with slight reductions for all-wheel-drive configurations.
Real-world data from Fuelly shows the 2023 Ram 1500 with the 3.0 EcoDiesel averaging 22.1 mpg, showcasing its strong diesel truck fuel mileage performance in the light-duty category. However, it’s worth noting that the EcoDiesel engine prioritizes fuel efficiency over raw power compared to larger diesel engines.
#1) Chevy Silverado / GMC Sierra 1500 3.0L Duramax – 23.2 MPG
The 3.0L LZ0 turbodiesel engine, often called the “Baby Duramax,” has been available in the Chevrolet Silverado and GMC Sierra 1500 since the 2023 model year. This engine excels in fuel economy.
EPA estimates rate it at 23 mpg city and 33 mpg highway, making it a leader in diesel truck fuel mileage. Real-world Fuelly data confirms this, with the Chevy Silverado 1500 3.0L LZ0 averaging 23.2 mpg, and the GMC Sierra 1500 slightly better at 23.7 mpg according to user submissions.
Beyond fuel efficiency, the 3.0L Duramax also offers a performance upgrade over the previous generation “Baby Duramax” (3.0L LM2), boasting 305 horsepower and 495 lb-ft of torque.
Calculating Your Diesel Truck’s Fuel Economy
Older diesel trucks, especially those without aftermarket upgrades, may not achieve their original EPA fuel economy ratings due to wear and tear. To get an accurate assessment of your truck’s current MPG, you can perform a simple calculation:
- Full Tank: Fill your fuel tank completely.
- Record Gallons: Note the number of gallons needed to fill the tank.
- Reset Odometer: Set your trip odometer to zero.
- Drive: Take a drive of a reasonable distance.
- Record Mileage: Note the miles driven from your trip odometer.
- Calculate MPG: Divide the total miles driven by the gallons used to refill the tank.
This calculation provides your truck’s MPG for that driving cycle. For example, if you drove 250 miles and it took 12 gallons to refill, your MPG is approximately 20.8 (250 miles / 12 gallons).
Remember that MPG can fluctuate based on driving conditions and truck usage. Towing or hauling will significantly reduce fuel economy. Repeating this test multiple times under various conditions will give you a more comprehensive understanding of your diesel truck fuel mileage.
Looking to boost your truck’s mileage and performance? Explore ProSource Diesel for a wide range of dependable diesel truck parts for Powerstroke, Cummins, and Duramax engines. ProSource Diesel is a trusted source for diesel repair shops and truck owners seeking reliable and hard-to-find diesel parts and kits.
