You should follow the diesel engine manufacturer’s recommendation, which is often around every 5,000 to 10,000 miles for light-duty work under normal conditions. In terms of timing, this is typically every 6 to 12 months. Heavy duty situations, such as towing, dusty conditions, or frequent idling, may require more frequent oil changes. If you use Valvoline™ Heavy Duty Synthetic Blend Diesel Engine Oil, you may be able to extend that interval safely, especially with regular oil analysis and clean filters. No matter the conditions and load, though, be sure to change your oil if it’s been in the engine for more than a year.

A diesel engine is a type of internal combustion engine that ignites fuel by compressing air until it’s hot enough to ignite injected diesel fuel, instead of using spark plugs. They are built to handle higher compression ratios, heavier loads, and frequent duty cycles. Diesel engines are commonly used in trucks, buses, generators, heavy equipment, and other applications where torque, durability, and fuel efficiency are crucial. It’s also found in off-road vehicles, where durability is essential.What is a diesel engine?

A diesel engine compresses air to a very high pressure and temperature, then injects diesel fuel which ignites from the heat of the compressed air. This means diesel engines don’t use spark plugs to ignite the fuel. Because of the high compression ratio, diesel engines are more fuel efficient and produce strong torque. They also tend to run hotter, increase NOx formation, and require oils designed to deal with heavy load, soot, and higher stress.

The main difference between gas and diesel engines is the fuel used and how it is ignited. Gasoline is a high-volatility fuel that ignites and burns quickly. Diesel fuel, on the other hand, is less volatile, and thus ignites slower and burns for longer. Gas engines use spark plugs and a pre-mixed air-fuel mixture, while diesel engines compress air alone, then inject fuel, letting it ignite from compression heat. Diesel engines usually have a higher compression ratio, produce more torque at lower RPMs, and use oil that must handle more soot, heat, and stress. Gas engines are typically quieter, less expensive to maintain in light use, and use oils with different additive sets focused on different performance needs.

Putting regular motor oil in a diesel engine will damage it. Regular motor oil often lacks sufficient detergents, soot control, and additive packages needed for diesel conditions. So, using it in a diesel engine can lead to faster oil breakdown, increased wear, and higher soot accumulation, leading to premature engine wear and potential catastrophic damage. It might satisfy immediate lubrication, but long-term protection will be compromised. In addition, using regular motor oil may void your vehicle’s warranty. Valvoline™ Heavy Duty Engine Oils are specifically formulated with additives to counter soot, acid, and high-pressure stresses that regular oil doesn’t handle well.