Whether they’re gas or diesel, all engines require lubrication. Without oil, they would quickly suffer catastrophic failure due to moving internal components experiencing high friction and heat beyond their tolerance levels.
Replacing your used engine oil with a fresh product is a cornerstone of good vehicle maintenance. Most passenger vehicles have gasoline engines, and owners may already understand the oil change process for those, but replacing used engine oil is equally important for owners with diesel engines. But are there any differences to consider when you’re performing a diesel oil change?
Gas vs. Diesel: How They Work
Both gas and diesel are types of combustion engines, which means they use fuel as a combustible source to create force in a combustion chamber that fires the pistons downward. The driveshaft converts this linear motion into rotational motion, carrying all the way to the wheels via the transmission and drivetrain.
Gas engines rely on fuel, air and spark to ignite in the chamber. Diesel engines, on the other hand, rely only on fuel and air for ignition. Under the right amount of pressure, and certain other conditions, diesel fuel combusts without the need for an external spark.
Differences in Composition
Since these two types of engines operate slightly differently, they have slightly different output in the exhaust stage. Diesel engines typically produce more contaminants like soot as a result of the combustion process. This is because they run hotter and under more pressure, and these conditions call for a different type of oil than what you’d put in a standard gas car.
Diesel engine oil has a higher viscosity, and it usually contains more additives and detergents to address the deposits. The actual process of changing the oil is much the same as with a gas engine, but the intervals are a bit longer — generally you should change it every 7,500 miles or as recommended by your manufacturer. The average interval for a gas engine is closer to 3,000 to 5,000 miles.
How To Change Diesel Oil
If you’ve changed your own oil for a gas-powered car, this process will be familiar: prepare your tools and materials, drain your oil, and remove and drain your filter. Next, replace the oil pan plug and engine oil filter, and then refill the tank with the correct type and amount of oil.
Dispose of your oil properly, and be sure to follow all manufacturer instructions and safety precautions along the way. If you’re taking your diesel vehicle into a shop for an oil change, expect to pay more than you would for a gas oil change, but take comfort in the fact that you won’t have to go as frequently.
Really, the differences between a gas and diesel oil change aren’t that substantial — just pay attention to the type of oil going into your vehicle, and you should be good to go.
Check out all the oil and oil change products available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on a diesel oil change, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photos courtesy of Blair Lampe.
Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter. In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.