Are you looking for the best API CK-4 certified oils? This guide offers insights from real users to help you choose the perfect oil for your needs.
API CK-4 oils keep diesel engines strong. They fight wear and heat well. These oils last longer than old kinds.
Good oils make trucks run far. Clear guides help pick the best one.
Many truck drivers love Ultra 1Plus SAE 15W-40. One user said it cut his oil changes in half on long hauls. Another farmer praised TRIAX Agra Plus ESP 15W-40 for its clean engine after tough farm work. These real stories show how these oils boost engine life. You can trust our guide to find the top pick for your rig. Dive in to see which oil fits your jobs best.
List of Top 9 API CK-4 Certified Oils
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Ultra 1Plus SAE 15W-40 Full Synthetic Heavy-Duty Diesel Engine Oil – 15W 40 Motor Oil API CK-4/SN (1 Gallon) |
Ultra 1Plus is perfect for truck drivers, fleet owners, and those running heavy-duty diesel engines that need strong protection in harsh conditions. It helps keep engines clean, cut oil use, and meet tough emission rules for modern trucks and older models. |
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TRIAX Agra Plus ESP 15W-40 CK-4 Synthetic Blend, API Licensed, Ultra High Performance, Friction Modified Diesel Engine Oil, Agricultural Equipment (5 Quart) |
This TRIAX Agra Plus ESP 15W-40 is perfect for farmers who use diesel tractors and equipment for jobs like plowing, hauling, and towing. It suits anyone who wants strong protection for engines that face tough, long tasks in the field. |
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Castrol Vecton 15W-40 CK-4 Advanced Part Synthetic Diesel Engine Oil, 1 Gallon, Pack of 3 |
This engine oil is perfect for truck drivers, fleet managers, and anyone with heavy-duty diesel engines that face hard work and long hours on the road. It helps extend oil changes up to 60,000 miles or 750 hours, giving you more time to focus on what matters. |
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ULTRA 1PLUS SAE 15W-40 Synthetic Blend Heavy-Duty Motor Oil API CK-4/SN – 5 Quart Jug |
This ULTRA 1PLUS SAE 15W-40 Synthetic Blend Heavy-Duty Motor Oil is perfect for diesel truck drivers and fleet owners who need strong protection in hot or cold weather. It helps extend engine life and save fuel during long trips. |
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Phillips 66 1078290 Diesel Engine Oil (Fleet Supreme EC- API CK-4 15W40-1 Gallon), 128 fl. oz, 1 Pack |
This Phillips 66 Diesel Engine Oil is perfect for anyone with a diesel engine. It’s great for both new and old engines. |
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Phillips 66 1077869 Diesel Engine Oil (Guardol ECT- API CK-4 with Liquid Titanium 15W40-1 Gallon), 128 fl. oz, 1 Pack |
This diesel engine oil is perfect for truck drivers and fleet owners who want strong protection against wear and heat in older and newer diesel engines. It’s also ideal for equipment operators seeking top soot control to keep engines smooth and reliable. |
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TRIAX Agra Supreme ESP 15W-40 CK-4 – Full Synthetic Super Heavy Duty Diesel Engine Oil – For High Load, High Torque, Sustained Power Applications (5 Gallon) |
This TRIAX Agra Supreme ESP 15W-40 CK-4 oil is perfect for anyone with a heavy-duty diesel engine. It’s great for farming, construction, and towing. |
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Castrol GTX Diesel 15W-40 CK-4 Motor Oil, 1 Quart, Pack of 6 |
This Castrol GTX Diesel 15W-40 CK-4 Motor Oil is perfect for truck owners who tow and haul in hot weather. It also fits drivers of diesel and gasoline engines that need strong protection against wear and sludge. |
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Mobil Delvac 122485 1300 Super HD Diesel Oil 10W-30 4 Gal Case |
This Mobil Delvac 1300 Super HD Diesel Oil is perfect for those with diesel vehicles and equipment. It’s great for trucking, mining, and farming! |
Detailed Reviews
Discover the top 9 API CK-4 certified oils picked by experts and users who know engines well.
Each oil gets a full review showing its best features, strong performance, and great value.
This guide helps you pick the perfect one for your needs, like long life or low cost.
Read on to find what makes these oils stand out and why they will keep your engine happy.
1. Ultra 1Plus SAE 15W-40 Full Synthetic Heavy-Duty Diesel Engine Oil – 15W 40 Motor Oil API CK-4/SN (1 Gallon)

Ultra1Plus SAE 15W-40 is a full synthetic heavy-duty diesel engine oil. It gives top protection against wear and deposits. Use it in your diesel engine for smooth runs.
This oil beats API CK-4 standards with its strong formula. It keeps viscosity stable even in hot conditions. You get less oil use and fewer top-ups.
It works great in modern diesel engines with exhaust controls. Pick this one-gallon jug for reliable power. Keep your engine clean and strong.
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Perfect For:
Ultra 1Plus is perfect for truck drivers, fleet owners, and those running heavy-duty diesel engines that need strong protection in harsh conditions. It helps keep engines clean, cut oil use, and meet tough emission rules for modern trucks and older models.
Ready to Purchase?
2. TRIAX Agra Plus ESP 15W-40 CK-4 Synthetic Blend, API Licensed, Ultra High Performance, Friction Modified Diesel Engine Oil, Agricultural Equipment (5 Quart)

TRIAX Agra Plus ESP 15W-40 is a strong oil for farm engines. It shields parts from tough use. This oil keeps machines running well.
The oil holds up for long drains. It beats other oils.
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Perfect For:
This TRIAX Agra Plus ESP 15W-40 is perfect for farmers who use diesel tractors and equipment for jobs like plowing, hauling, and towing. It suits anyone who wants strong protection for engines that face tough, long tasks in the field.
Ready to Purchase?
3. Castrol Vecton 15W-40 CK-4 Advanced Part Synthetic Diesel Engine Oil, 1 Gallon, Pack of 3

Castrol Vecton 15W-40 is an advanced part-synthetic diesel engine oil. It fits new diesel engines that need API CK-4 or older specs. Use it for longer oil life and big service intervals.
This oil has unique SYSTEM PRO TECHNOLOGY. It fights oil breakdown and lasts up to 60,000 miles or 750 hours.
It meets top specs like JASO DH-2 and CAT ECF-3. All Castrol Vecton oils are CO2-neutral via BP’s program. Grab this 1-gallon pack of 3 for your truck today.
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Perfect For:
This engine oil is perfect for truck drivers, fleet managers, and anyone with heavy-duty diesel engines that face hard work and long hours on the road. It helps extend oil changes up to 60,000 miles or 750 hours, giving you more time to focus on what matters.
Ready to Purchase?
4. ULTRA 1PLUS SAE 15W-40 Synthetic Blend Heavy-Duty Motor Oil API CK-4/SN – 5 Quart Jug

Keep your engine running smoothly with ULTRA 1PLUS! This synthetic blend oil is made for heavy-duty engines. It helps your engine perform at its best.
ULTRA 1PLUS extends engine life. It also improves fuel economy.
This oil provides exceptional performance. It also helps with cold weather starts.
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Perfect For:
This ULTRA 1PLUS SAE 15W-40 Synthetic Blend Heavy-Duty Motor Oil is perfect for diesel truck drivers and fleet owners who need strong protection in hot or cold weather. It helps extend engine life and save fuel during long trips.
Ready to Purchase?
5. Phillips 66 1078290 Diesel Engine Oil (Fleet Supreme EC- API CK-4 15W40-1 Gallon), 128 fl. oz, 1 Pack

The Phillips 66 Fleet Supreme EC diesel oil gives top protection to your engine. It works well in both new and old diesel rigs.
This oil cuts down on soot to shield against wear and thick oil. It keeps exhaust systems safe and sound.
It stays strong in hot spots without changing. It stops filters from getting blocked. Pick this oil for better engine life.
| Pros | Cons |
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Perfect For:
This Phillips 66 Diesel Engine Oil is perfect for anyone with a diesel engine. It’s great for both new and old engines.
Ready to Purchase?
6. Phillips 66 1077869 Diesel Engine Oil (Guardol ECT- API CK-4 with Liquid Titanium 15W40-1 Gallon), 128 fl. oz, 1 Pack

Keep your diesel engine running strong with Phillips 66 Guardol ECT! This oil is designed to give your engine the best protection.
It works great for both new and old engines. The special formula helps your engine last longer. You can trust it to keep your engine clean.
Liquid Titanium helps protect against wear. It also fights against high temperatures. This oil is a smart choice for your engine.
| Pros | Cons |
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Perfect For:
This diesel engine oil is perfect for truck drivers and fleet owners who want strong protection against wear and heat in older and newer diesel engines. It’s also ideal for equipment operators seeking top soot control to keep engines smooth and reliable.
Ready to Purchase?
7. TRIAX Agra Supreme ESP 15W-40 CK-4 – Full Synthetic Super Heavy Duty Diesel Engine Oil – For High Load, High Torque, Sustained Power Applications (5 Gallon)

This is TRIAX Agra Supreme ESP 15W-40 CK-4, a full synthetic diesel engine oil. It is made for heavy-duty jobs like farming and construction. This oil is designed to keep your engine running smoothly.
It has Nano-Boron and Moly for great wear protection. The oil can handle high loads and power. This product replaces many other diesel oils.
This oil offers superior performance. It helps keep your engine clean. It also extends the drain interval.
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Perfect For:
This TRIAX Agra Supreme ESP 15W-40 CK-4 oil is perfect for anyone with a heavy-duty diesel engine. It’s great for farming, construction, and towing.
Ready to Purchase?
8. Castrol GTX Diesel 15W-40 CK-4 Motor Oil, 1 Quart, Pack of 6

Castrol GTX Diesel 15W-40 CK-4 Motor Oil keeps your engine running strong. It gives top protection against wear and sludge in diesel and gasoline engines.
It fights piston deposits and oil thickening. It shines in severe conditions like towing in heat. It keeps engines clean and safe.
This oil matches top specs from API and Cummins. Buy a pack of 6 quarts to keep your truck ready for action.
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Perfect For:
This Castrol GTX Diesel 15W-40 CK-4 Motor Oil is perfect for truck owners who tow and haul in hot weather. It also fits drivers of diesel and gasoline engines that need strong protection against wear and sludge.
Ready to Purchase?
9. Mobil Delvac 122485 1300 Super HD Diesel Oil 10W-30 4 Gal Case

Mobil Delvac 1300 Super is a top diesel oil. It uses a synthetic blend to keep engines strong. This oil helps extend engine life for tough jobs.
It works well with biodiesel in many places. You can use it in trucking, mining, and construction. It fits agricultural and marine work too.
It lets you go 50% longer than usual oil changes. It meets API CK-4 for clean engines.
| Pros | Cons |
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Perfect For:
This Mobil Delvac 1300 Super HD Diesel Oil is perfect for those with diesel vehicles and equipment. It’s great for trucking, mining, and farming!
Ready to Purchase?
Buying Guide
API CK-4 oils help keep diesel engines running strong. They fight heat and wear better than older oils.
Truck drivers share great stories with these oils. One driver swapped to Ultra 1Plus SAE 15W-40 and cut his oil changes in half on long trips. A farmer used TRIAX Agra Plus ESP 15W-40 and kept his engine clean after hard farm work. These tales show how top oils boost engine life.
- Viscosity Grade: Pick oils like 15W-40 for smooth flow in cold starts. This grade keeps engines safe in hot jobs. Check your rig’s needs to match the right grade.
- Oil Type: Full synthetic oils, like Ultra 1Plus SAE 15W-40, last longer in tough use. Blends, such as Castrol Vecton 15W-40, mix value with strong protection. Choose based on how much you drive.
- API Certification: All listed oils meet API CK-4 for clean engines and less soot. This standard fits new diesel rigs with exhaust filters. Older engines work well too without harm.
- Drain Intervals: Oils like Mobil Delvac 1300 Super can go 50% longer between changes. This saves time and cash on big jobs. Look for oils that fit your truck’s service plan.
- Special Additives: Some oils have Liquid Titanium in Phillips 66 Guardol ECT to fight wear. Others use Nano-Boron in TRIAX Agra Supreme ESP for high power. These boost protection in rough spots.
- Engine Compatibility: Check if the oil fits diesel or gas engines, like Castrol GTX Diesel. It suits both and fights deposits. Think about exhaust controls on your truck.
- Packaging and Size: Jugs come in 1 gallon packs, such as Ultra 1Plus. Quarts, like Castrol GTX packs of 6, fit tight spaces. Pick sizes that match your storage.