7 Best Synthetic Oils for Diesel Engines

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Your diesel engine’s life depends on one thing – using the right oil. We’ll cut through the noise on diesel motor oils to reveal which ones nurture long engine life versus those that fizzle fast.

Arm yourself with the knowledge you need to pick the perfect synthetic oil to avoid constant worry. Your engine will hum for years when treated right.

best synthetic oil for diesel engines

Read Also: Where Is the Cheapest Place to Buy Synthetic Motor Oil?

Top 7 Synthetic Oils for Diesel Engines

Below are some of the best synthetic oils for diesel trucks and cars. Note that all of these come in either 1-gallon or 5-liter (1.32 gallon) containers and some are sold in multiple containers for the absolute best value.

Related: Symptoms of Having the Wrong Engine Oil in Your Car or Truck

#1 – Motul 8100 X-cess Synthetic Engine Oil

Motul X-cess synthetic motor oilMotul was the first to develop a 100% synthetic oil all the way back in 1971 and they continue to be innovators in synthetic motor oils. Motul 8100 X-cess is a unique synthetic in that it can be used in either diesel engines or gasoline engines.

The oil is specially formulated to be 100% synthetic and is ideal for high displacement engines both diesel and direct injection gasoline. This specific product is sold in cases of 4 jugs totaling 20 liters altogether. Yes, it’s a bit more expensive but whether your truck has a Duramax or Power Stroke engine, it’s hard to beat Motul 8100 X-cess.

#2 – Shell Rotella T6 Heavy Duty Diesel Synthetic Oil

Shell Rotella T6 synthetic oilLikely the most popular synthetic oil for diesel engines, Shell Rotella T6 is another excellent 100% synthetic oil that is suitable for diesel engines and arguably the best when you factor in its price. If the Motul is a bit out of your price range, Rotella T6 is a great alternative.

Shell Rotella T6 classifies itself as a heavy duty diesel engine oil and can handle multiple kinds of driving conditions. Whether you need low temperature protection or high temperature protection, this oil will satisfy both of these requirements.

See Also: Best Oil Filters for Synthetic Motor Oil

#3 – Schaeffer SynShield Synthetic Plus Diesel Engine Oil

Schaeffers synthetic diesel engine oilThis synthetic diesel engine oil has many advanced features, such as resistance to oxidation, extra wear protection, and better handling of soot. It is best to use the Schaeffer SynShield in conjunction with diesel fuel that has very low sulphur levels.

Schaeffer synthetic motor oil for diesel vehicles meets and exceeds API CK-4 meaning that it reduces friction and wear in the most severe operating conditions. When you want the best and don’t mind paying a bit more, Schaeffer Manufacturing is hard to beat.

#4 – Liqui Moly Diesel High Tech Synthetic Motor Oil

Liqui Moly synthetic diesel oilMany car enthusiasts swear by Liqui Moly products whether it’s a fuel injector cleaner, engine flush, or other additive, and their line of motor oil products are top notch, yet spendy.

Made in Germany, Liqui Moly synthetic oil for diesel engines offers unsurpassed protection against friction and wear and has the ability to last thousands of miles longer than other diesel motor oils before losing effectiveness. You’ll likely gain a small increase in fuel economy when switching over.

#5 – Mobil 1 Turbo Diesel Truck Synthetic Motor Oil

Mobil 1 turbo diesel truck motor oilFor many years, Mobil 1 synthetic oil has been near the top of every list for gasoline powered vehicles and for good reason. While not as popular for diesel powered engines, Mobil 1 Synthetic for Turbo Diesel Trucks offers that same protection.

It’ll protect your engine in a huge temperature range to keep sludge and varnish buildup to a minimum. Mobil 1 will keep your engine cleaner are running cooler and more efficient whether you’re cruising on the highway or towing a trailer up a steep incline.

#6 – Ford Motorcraft Synthetic Diesel Motor Oil

Ford Motorcraft synthetic oil for diesel trucksIf you drive a Ford Power Stroke diesel, running genuine Motorcraft full synthetic diesel motor oil in your engine is a no brainer. It’s the only motor oil recommended by Ford Motor Company and the same one used at the service departments of Ford dealerships.

No matter if you drive an F150 or F350 diesel truck or other vehicle that requires CJ-4 guidelines, it’s hard to go wrong with Motorcraft oil. Your engine will stay cleaner, run cooler, get better fuel economy, and you’ll be able to go longer between oil changes.

#7 – Lucas Oil CJ-4 Synthetic HD Motor Oil

Lucas Oil synthetic motor oilLucas Oil Products Inc. is another American company that makes excellent motor oil. This type of fully synthetic motor oil is formulated to perform well heavy duty diesel engines (from pickup trucks to semi trucks) as well as gasoline engines, no matter their age.

Like other premium brands, you’re going to pay a bit more up front for Lucas Oil synthetic motor oil but your engine will be well protected even after other synthetic oils start breaking down.


Is Synthetic Oil Better for a Diesel Engine?

Yes, synthetic oil can offer various benefits for diesel engines. Synthetic oil, compared to conventional oils, has been known to improve the engine’s performance, increase fuel efficiency, and provide better protection during cold starts. Additionally, synthetic oil often lasts longer, which means fewer oil changes are required.

How Often Should You Change Synthetic Oil in a Diesel?

As with any vehicle, it’s always best to consult the vehicle’s owner’s manual for specific guidance on oil change intervals.

However, the frequency of changing synthetic oil in a diesel engine depends on several factors, such as driving conditions, engine load, and manufacturer recommendations.

Generally, under normal driving conditions, it is recommended to change synthetic oil in a diesel engine every 7,500 to 10,000 miles or once a year. However, if the vehicle is used for heavy towing or extensive idling, the oil change interval may need to be reduced to 3,000 to 5,000 miles or every three months.

Which Synthetic Oil Grade Is Recommended for Turbo Diesel Engines?

The recommended grade of synthetic oil for your turbo diesel engine will depend on your vehicle’s make and model. Your owner’s manual will have this info and in most cases, the oil fill cap will have the recommended oil specifications engraved or printed on it.

One common synthetic oil grade for turbo diesel engines is 5W-30.

Are There Differences Between Synthetic Oils for Gas and Diesel Engines?

Yes, there are differences between synthetic oils specifically designed for gas and diesel engines. Diesel engine oils usually have higher anti-wear and detergent additive concentrations because diesel engines produce more soot and contaminants during combustion. This feature helps keep the engine clean and protected from wear.

On the other hand, synthetic oil designed for gasoline engines might have different additive packages that focus more on protecting metal surfaces, reducing friction, oxidation, and maintaining viscosity stability.

This is why it’s so important to use the correct synthetic oil for your engine type, as using the wrong one can lead to reduced performance and potential engine damage. Always follow your vehicle manufacturer’s guidelines to ensure you are using the proper synthetic oil for your engine.

Mark Stevens


    1. Any API certified synthetic will do the work for you, no need of an Xbrand….they all must meet the same certification.

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