There was a time when diesel engines were associated with smoke, soot, noise, and lackluster performance. But as ultra-low sulfur diesel fuel got better along with new tech advancements, the diesel engine became quieter, more powerful, and even more reliable than ever before. The advent of turbocharging and common rail direct injection (CRDI) have made diesel engines even more potent than early diesel models.

Car buyers choose diesel over gas for three main reasons: superior torque production, long-term durability, and fuel economy. However, diesel engines require more care and maintenance to keep them running smoothly. Without regular maintenance, you are increasing the chances of early breakdowns and expensive repairs.

With that in mind, here are the top 5 diesel maintenance tips that will keep your diesel car, truck, or SUV running smoother for longer.

Top 5 Diesel Maintenance Tips

1. Warm it up.

The biggest mistake you can make to a diesel engine is to force it to rev while the motor is cold. Sure, diesel engines are more robust and have thicker castings and cylinder walls, but cold starts will harm a diesel just as much as a gasoline engine.

After starting your diesel car (whether in the morning, afternoon, or evening), allow it to idle for a minute or two before driving off. Warming up the engine enables the oil to circulate and lubricate the critical parts inside the motor, particularly the turbocharger.

2. Monitor the condition and level of engine coolant.

Like a comparable gasoline engine, diesel motors produce tons of heat during operation. The coolant circulating inside your diesel engine absorbs heat, lubricates the water pump, and keeps your diesel from overheating under extreme duress. Check the coolant level regularly and replenish as needed. Open the hood, locate the coolant reservoir, and check if your engine is running on sufficient coolant.

In addition, the coolant in most diesel engines will turn acidic over time, which is terrible news for the metal and aluminum parts in the cooling system. You can have your mechanic check the acidity level of the coolant, or you can flush out the old coolant and replenish it with a fresh batch as prescribed in the maintenance schedule of your diesel vehicle.

Make it a habit to check for acidic coolant every six months or so, and flush the cooling system every two years or every 50,000 kilometers. When in doubt, check the owner’s manual.

3. Periodically change the oil.

It doesn’t matter if you have a gasoline or diesel car. Regularly changing the oil is cheap insurance against costly repairs. And while gasoline-powered vehicles require an oil change every 5,000 to 8,000 kilometers, diesel engines require more frequent oil changes depending on the type of vehicle.

Also, the oil will deteriorate faster under harsh operating conditions like towing or carrying heavy loads. For most diesel engines, the general rule is NOT to exceed one year or roughly 15,000 kilometers without changing the oil.

Under normal conditions, diesel engines need an oil change every 8,000 kilometers. But under heavy use (towing, prolonged engine idling, high-mileage driving, etc.), diesel engines require an oil change every three months or 4,000 kilometers. Again, check the owner’s manual to be doubly sure. It’s also a good idea to pull out the oil dipstick and check the oil condition at least once a week.

4. Replace the fuel filters.

Older diesel engines may have only one fuel filter, but most modern diesel motors have two: a primary and a secondary fuel filter. When it comes to diesel engines, cleanliness is next to Godliness. Many people don’t know that excess dirt and grime is a surefire way to kill a diesel engine prematurely.

The fuel filters keep dirt, water, and contaminants away from the injectors and are the most vital parts of a modern diesel engine. If one or more of the injectors get clogged up, your diesel motor will run poorly. Keep in mind that impurities in the fuel can quickly wreak havoc on your diesel car or truck. Remember to replace the fuel filters every 16,000 to 25,000 kilometers.

5. Replace the air filter.

Like how the fuel filters protect modern diesel mills from dirt and debris, the air filters do the same job. If you have a diesel car, replacing the air filter every 25,000 kilometers is good practice, although you may need to change the air filter more frequently if you do a lot of towing or long-distance hauling.

A dirty air filter leads to poor acceleration, mediocre fuel economy, and hard starting, to name a few. Also, a clogged air filter restricts engine breathing. On the plus side, it’s easy to replace the air filter in your vehicle. As usual, don’t forget to check the owner’s manual to know the prescribed replacement intervals for the air filter in your diesel car.