What Is Considered High Mileage For A Diesel?

Ram truck driving long-distance trip.

When it comes to engine comparison, it will be safe to say that diesel engines are more durable than gas engines and get higher mileage than gas engines. Diesel engines are characterized by significant longevity compared to gas engines. Moreover, diesel engine architecture is stouter compared to the gas engine, and its applications require a long life to offset the high initial purchase price. Thus, high mileage diesel engines have a better way of retaining more significance and value over time. 

You can still purchase a pickup with some hundred thousand miles and even offer you a reliable transportation mode. Yet, the remaining years of reliability still depend on how faithful the previous owners maintained the pickup. Nevertheless, regular maintenance service is crucial to the automobile’s getting into the million-mile club.

What are Heavy-Duty Diesel Engines?

There are different categories used when discussing high mileage when it comes to diesel engines. For example, a class-8 truck may log 750,000 miles or even more before it qualifies for a high mileage vehicle. This is because it is relatively common for a class-8 truck to register 1,000,000 miles if it gets regular maintenance. 

When it comes to pickup trucks with diesel engines, you will notice that they get higher mileage than gas trucks because of their more durable engines, capable of withstanding higher compression ratios. 

Even if the diesel truck is extensively utilized for hauling and towing, it will still last even beyond the 100,000 miles. Hence, you will often see diesel pickups registering even up to 300,000 miles and still commands a reasonable resale price. It will be useful to note that high mileage will not necessarily mean that a truck is nearing its end of life.

Not all High Mileage Vehicles are Equal

You may be taken aback upon seeing that the vehicle you are eyeing to buy registers over 100,000 miles, considering that it is only three years old. Such a figure may be indicative of the fact that the vehicle has been used extensively. Nevertheless, it will be useful to note that new cars are very robust that even if they have registered 100,000 miles within three years, they would still be in good condition unless indicated otherwise by some signs and symptoms or you are sure that the brakes and types have not undergone much maintenance. 

When it comes to diesel pickups, it will also be useful to remember that high mileage diesel pickups are not the same. You may be looking, for example, at a diesel pickup that registers 100,000 miles and has been used extensively for hauling and towing heavy loads. Such a pickup may require significant repairs. 

Nevertheless, you will also find a lightly used diesel pickup that registers 200,000 miles and still exhibits outstanding reliability and trouble-free life. Moreover, it will help if you consider other important factors often used to determine the diesel truck’s life expectancy aside from the mileage recorded on the odometer. Such factors include the following: maintenance records, current condition, number of owners, primary use, and accidents.

A diesel pickup, for example, that records 200,000 miles or more that has changed ownership twice and with good maintenance records may be better than a diesel pickup with a 100,000-mile truck that has undergone four ownership changes. 

Moreover, it will help if you consider the overall appearance and condition of the truck. Check if the truck has a well-maintained interior and exterior because it may indicate that it is mechanically well-maintained.  

High Mileage for Diesel Pickup Trucks (Cummins)

If you would examine the Dodge and Ram diesel truck lines, you will discover that their engines are of the Cummins brand name. These engines are expected to be long-lasting, and the range considered to be of high mileage for these engines is between 350,000 to 500,000 miles. 

Nevertheless, you should also consider if the truck has undergone high maintenance. If the engine is well-maintained, but the truck’s other parts are not, chances are the truck itself will not continue to survive.

High Mileage for Duramax Diesel Pickup Truck

Another diesel engine brand is the Duramax, found mostly in trucks rolled out by General Motors, including Chevy and GMC trucks. There is a varying opinion when it comes to high-mileage Duramax engines. Some say that for Chevy diesel trucks with 100,000 miles is already high mileage. However, others maintain that 350,000 miles should be of high mileage. Yet, maintenance will always play a crucial factor when determining the condition of the truck.

Powerstroke Diesel Pickup Truck’s High Mileage

You will see the Powerstroke engine in Ford trucks. These engines can last up to around 500,000 miles. Like Cummins and Duramax, a Powerstroke engine belong to high-mileage engines if it has already registered between the range of 350,000 and 500,000 miles. 

Like in the case of Duramax and Cummins, the engine and truck’s overall condition depends on how well the trucks were maintained. Nevertheless, it will be good to remember that the Ford trucks belong to the most popular truck brands in the U.S. They are known for their consistent reliability.

Factors to Consider When Buying a High Mileage Diesel Truck

When buying a diesel pickup truck with around 250,000 mileage or more, it will be useful to consider several factors so that you can figure out if a truck is worth buying. For example, you should have the service documentation checked to make sure that the engine is well maintained. Afterward, do a transmission and engine service quickly after purchasing. Then, inspect the chassis thoroughly. 

After that, service the drivetrain. Then, switch to the use of synthetic gear and engine oil. You should also check the car’s cooling system. Furthermore, you should bear in mind that some engines have specific problems.

Concerning the Problem of Oil Leak

It is not unusual that high-mileage engines often experience oil leaks. So, you should not be surprised if the second-hand vehicle you are eyeing to buy exhibits oil leaks. Remember that minimal leaks around the seals and gaskets are common among used cars with high mileage. 

Nevertheless, if you see a heavy coating of oil in the area surrounding the gasket and seal, it must cause an alarm in you. Remember that the amount of oil covering the area would be your basis. But small oil leak in a high-mileage diesel should not lead you to break a deal.

Research On the Specific High-mileage Diesel Engines and Truck You Would Like to Buy

Trucks feature different engines and different engine problems too. So, before you buy a truck, you should engage in thorough research of that truck’s engines and the vehicle itself. Remember that even if the engine model of the truck appears to have no issues, if the vehicle comes with many problems, you might as well think twice about buying it. 

So, when purchasing a high-mileage truck, you should also research the issues that hound that truck. Ask for the maintenance record so that you can check on the maintenance record of the vehicle. For example, you should check if the water pump has been replaced in the past years, for if there was no replacement for 150,000 miles, you might be forced to engage in costly repairs of it.


There is no single high mileage range for a diesel pickup truck. Yet, if the truck has already reached 500,000 miles, it is generally considered of high mileage. Nevertheless, despite the odometer registering high mileage, there are still other factors to consider when buying a used truck. For example, it is better to buy a well-maintained, high-mileage vehicle than a poorly maintained vehicle with lower mileage.

You should also engage in a background check of the prospective vehicle before you even close the deal. Check about the repair history, ownership, reported accidents, and many other factors that could give you a good idea about the vehicle you will buy.