Manufacturers of light-duty trucks and cars, whether diesel or gas, are required to report an estimate of fuel economy to the Environmental Protection Agency (EPA). You’ll find these estimates on the window stickers of new vehicles sold on dealership lots. It’s also easy to find EPA estimates in reviews for these new vehicles. The only exception to this is heavy-duty (HD) trucks. Manufacturers of trucks with a gross vehicle weight rating of over 8,500 pounds are not required to report fuel economy estimates.
When it comes to the best MPG for a diesel truck, you’ll generally find it in newer light-duty pickups with the smaller versions of Cummins, Powerstroke, and Duramax diesel engines. In general, the lighter the truck the better fuel economy it usually has. This means that 2WD versions of any given truck model usually get better MPG than its 4WD version.
Let’s take a closer look.
The main factors that contribute to fuel economy in any vehicle include the following:
Stock trucks can almost always be modified for improved fuel economy with aftermarket diesel parts that create better airflow and more efficient fuel flow. A well-maintained truck will also get better fuel economy vs. one that is in poor condition. How you drive your truck impacts fuel economy as well. Many diesel trucks can achieve at least 20 MPG on the highway when not towing or hauling.
As previously mentioned, Manufacturers of HD trucks are not required to report fuel economy numbers. However, publications like Consumer Reports often do real-world tests on these trucks to see how they stack up. One recent test found that HD diesel trucks actually get 1-2 MPG less than gas trucks of the same size. This is mainly due to the heavier weight of HD trucks.
The diesel Chevy Silverado 2500 HD (which is virtually the same as the GMC Sierra 2500 HD) has a 6.6-liter V8 Duramax turbodiesel paired with a six-speed Allison automatic transmission. The version tested by Consumer Reports was a four-door, 4WD trim. Overall MPG for the Silverado 2500 HD is 14 MPG.
Ford F-250 HD
The F-250 comes with a 6.7-liter Powerstroke turbodiesel V8, which puts out enough horsepower to make it faster than its rivals the Silverado 2500 and Ram 2500. It’s also built with an aluminum-alloy body, which makes it lighter than the average HD truck. The overall MPG on the F-250 four-door Lariat trim as tested by Consumer Reports is 15 MPG.
The Titan is built to fit categorically in between lighter half-ton trucks and heavy-duty three-quarter-ton trucks. The Titan sports a smaller Cummins diesel engine in the 5.0-liter V8 turbo diesel. Despite the lighter engine, a four-door SV trim Titan still only manages 15 MPG overall.
The Ram 2500 comes with a 6.7-liter Cummins inline-six turbodiesel that is known for its massive amount of torque. It’s paired with a six-speed automatic transmission. As tested in a four-door Laramie trim, the Ram 2500 manages 14 MPG overall.
The big three truck manufacturers all have smaller diesel engines in their light-duty pickups. For the GM trucks, there are two smaller versions of the Duramax engine. For the Ford truck, there is a smaller Powerstroke. Ram trucks have EcoDiesel engines in the new 1500s. These trucks often get twice the fuel economy of their larger cousins. However, it can vary depending on the trim and layout.
This truck features a 3.0-liter Powerstroke V6 turbodiesel. In the indicated configuration, it is EPA-rated to get 29 MPG on the highway, 21 MPG in the city, and 24 MPG combined. A 4WD configuration of the same truck can get 28 MPG highway, 21 MPG city, and 24 MPG combined.
The Canyon features a 2.8-liter Duramax turbodiesel four-cylinder. In the indicated configuration, it is EPA-rated to get 20 MPG in the city, 23 MPG combined, and 30 MPG on the highway. The Chevy Colorado has the same engine and is basically the same truck, so it gets the same fuel economy.
The light-duty Ram manages 32 MPG on the highway, 22 MPG in the city, and 26 MPG combined for a 2WD layout. The 4WD gets 29 MPG highway, 21 MPG city, and 24 MPG combined. The engine here is a 3.0-liter V6 EcoDiesel.
The new Chevy Silverado offers the best fuel economy for a diesel truck. It gets 33 MPG highway, 22 MPG city, and 27 MPG combined. The GMC Sierra 1500 is basically the same truck, but fuel economy figures are lower at 30 MPG highway, 23 MPG city, and 26 MPG combined. 4WD versions of both trucks get slightly less MPG than their 2WD counterparts. The Silverado has a 3.0-liter Duramax turbodiesel.
If you have an older diesel truck or a truck modified with aftermarket diesel truck parts that improve fuel economy, your numbers aren’t likely to match the original stock EPA ratings. In order to find out your fuel economy, you can take the following steps:
The result of this equation is how many MPG your truck got during the drive. For example, if you drove 250 miles and it took 12 gallons to fill the tank, then your fuel economy would be roughly 20.8 MPG.
It’s important to remember that your MPG might vary considerably depending on where you drive your truck and if it’s hauling or towing. To get a more accurate idea of your average MPG, you should test your truck’s MPG several times to see if the numbers are different.
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