The 10 Best Synthetic Oils

We spent 46 hours on research, videography, and editing, to review the top options for this wiki. Synthetic oil provides superior lubrication and protection to nearly every internal combustion engine. Most formulas for gas-powered vehicles are almost identical, and on this list are the best consumer blends that meet the latest standards. For specific applications, such as diesels, dirt bikes, and drag racing, though, you’ll want to be completely certain you’ve selected the right variety. When users buy our independently chosen editorial picks, we may earn commissions to support our work.

10. Pennzoil’s Marine Premium Plus

If your vehicle lacks wheels but has an outboard, Pennzoil’s Marine Premium Plus is definitely worth a look. It’s certified to be safe and effective during long-term operation in water-bound engines, which is a claim most 2-stroke products can’t make.

  • Helps prevent carbon deposits
  • Durable under extreme conditions
  • Doesn’t burn 100-percent cleanly

Brand Pennzoil
Model 550045220
Weight 7.7 pounds
Rating 3.5 / 5.0

9. Valvoline Non-Detergent

Valvoline Non-Detergent lacks the friction modifiers and anti-foaming agents of most formulas, and it hasn’t been used in cars for decades. Instead, it’s made with minimal additives, for light-duty four-stroke units in certain gas-powered tools and landscaping equipment.

  • Similar to the first auto lubricants
  • Inherently resists oxidation
  • Only works with particular engines

Brand Valvoline
Model 822382
Weight 2 pounds
Rating 3.6 / 5.0

8. Red Line 15W50

If you couldn’t resist bolting a turbocharger to your Honda, consider Red Line 15W50, which is roughly halfway between standard oil and racing lube. If your daily driver uses forced induction, and also sees time on the track, this is the brand for you.

  • Ideal for high-compression setups
  • Ample zinc and phosphorous content
  • Not for use in cold climates

Brand Red Line Oil
Model 11505
Weight 8 pounds
Rating 4.9 / 5.0

7. Royal Purple HP 2-C

Dual-sport riders absolutely love Royal Purple HP 2-C for its high-RPM performance. And, because there’s not an excess of identical products vying for attention, most motocross enthusiasts are on the same page — this is about as good as dirt bike oil gets.

  • Great in rich or lean mixtures
  • Works wonders in a chainsaw
  • Only for use in 2-cycle engines

Brand Royal Purple
Model ROY04311
Weight 7.5 pounds
Rating 4.1 / 5.0

6. Valvoline VR1

Valvoline VR1 is relatively similar to most consumer-grade synthetics, except it contains high levels of zinc and phosphorous, which protect old-school flat-tappet camshafts from damage. It may not truly be racing quality, but it is good for Stage 1 street rods.

  • Effective anti-foaming properties
  • Ideal for classics and push-rods
  • A step up from oem-grade oil

Brand Valvoline
Model 822388-6PK
Weight 12 pounds
Rating 4.1 / 5.0

5. Castrol GTX High Mileage

Castrol GTX High Mileage is specially formulated with a high detergent content, which may help maintain the flexibility of aging seals, potentially increasing the powertrain’s lifespan. It won’t fix any existing leaks, but it could help prevent them in the future.

  • Protects against burn-off
  • Fits into the smallest budgets
  • Not for use in low-mileage cars

Brand Castrol
Model 03102C
Weight 9.3 pounds
Rating 4.4 / 5.0

4. Mobil 1 Extended Performance

Mobil 1 Extended Performance keeps your vehicle alive and well by staying slick and lubricating for up to 15,000 miles between services. This one is a good choice for drivers who tend to put off maintenance until the last possible moment.

  • Suitable for old and new cars
  • Exceptional oxidation prevention
  • Compatible with all makes and models

Brand Mobil 1
Model 120766
Weight 9.3 pounds
Rating 4.2 / 5.0

3. Royal Purple XPR

One of the few lubricants whose reputation precedes it, Royal Purple XPR has long been a favorite at drag strips and bracket races. It is considerably expensive, but it’s worth it to those who will spare no expense in the quest for victory.

  • The ultimate in high-rpm protection
  • Cleans and cools as it lubricates
  • Can increase power and efficiency

Brand Royal Purple
Model 1011
Weight 12.1 pounds
Rating 4.5 / 5.0

2. Shell Rotella T6

Shell Rotella T6 is designed to accommodate the specific operating conditions and particulate levels unique to diesel engines. It’s inherently capable of handling extreme climates, and just like diesel sedans, it’s quite economical.

  • Recommended by countless pros
  • Helps turbochargers remain efficient
  • Used in some modified gasoline cars

Brand Shell Rotella T
Model 550045347
Weight 7.5 pounds
Rating 4.8 / 5.0

1. Pennzoil Ultra Platinum

The vast majority of drivers’ needs will be filled by Pennzoil Ultra Platinum, because most passenger car motor oil is the same, and this one’s about the cheapest. It’s crafted to all the latest specifications, and works in most vehicles made in the last 50 years.

  • Meets emissions requirements
  • Officially endorsed by bmw
  • Lasts 10000 miles between changes

Brand Pennzoil
Model 550045201
Weight 9.3 pounds
Rating 4.6 / 5.0

Why Oil Is So Important

Oil is the lifeblood of an engine and without it, your engine would overheat, wear down, and destroy itself in a very short period of time. There are three vital functions oil performs inside of an engine to keep it running smoothly for years: lubrication, cooling, and removal of contaminants.

Inside on an engine are many moving metal parts that are operating thousands of an inch of each other. If (and when) these surfaces touch, they abrade each other, shaving off microscopic debris. Without thin molecules of oil separating the parts, lubricating them, and reducing friction, several things can happen. The metal parts may heat up and distort, causing them to bang together, causing further damage. Metal shavings from one may rub off onto another in a process called galling. The piston could even get stuck in the cylinder bore, causing the engine to freeze up. All of these things can lead to permanent engine failure.

Internal combustion engines make use of thousands of controlled detonations every minute. This creates the force needed to move the engine components and propel your car forward. These detonations can cause a significant buildup of heat. As oil travels through your engine, it draws heat away from the combustion chamber and allows it to dissipate in the oil pan. This helps to keep your engine from overheating.

As an engine runs, it creates contaminants. These can be bits of metal that result from wear on the metal parts or a buildup of carbon as a byproduct of the combustion. Motor oil not only carries these contaminants away as it travels though the system and deposits them in the oil filter, but it also contains a number of additives to prevent them. Common motor oils contain additives such as rust inhibitors, detergents, and dispersants.

What Is Synthetic Motor Oil And How Is It Made?

Synthetic oil is a lubricant that is used as a substitute for petroleum-refined oils. Unlike standard motor oils, it is not distilled from crude oil. Instead, it is made from materials like carbon dioxide, methane, and carbon monoxide through a chemical process known as the Fischer-Tropsch process. This results in a cleaner oil, which has more uniform hydrocarbon molecules. It also doesn’t contain any of the unnecessary compounds found in crude-based oils, like paraffin wax. All of this makes synthetic oil better for extreme temperatures applications.

There are two types of synthetic oil: full-synthetics and semi-synthetics. Full-synthetic oils can be derived from crude oil or from other chemical compounds. If it is derived from crude oil, it is done with the aforementioned Fischer-Tropsch process instead of the traditional distilling method. This results in an oil with more uniform properties that is better suited to the mechanical applications it is designed for.

Semi-synthetic oils are a combination of traditional mineral motor oils and synthetic oils. This special blend of oils results in a motor oil that does a better job of protecting an engine, as can be expected from full-synthetics, but at a lower cost. The first semi-synthetic motor oil was introduced in 1966 by Motul. They also released Century 300V, which was the first 100% synthetic lubricant created for cars.

Benefits Of Synthetic Motor Oil

Because synthetic motor oils are created rather than distilled, they can tailored to the demands of modern car engines. Customized oil molecules with less useless impurities results in a higher quality lubricant that easily out performs its mineral-based counterpart. Synthetic oil’s ability to deal with the extreme conditions encountered in internal combustion engines shows itself in a number of ways. It is easier to pump at low temperatures, which is extremely important as this means it can fully circulate through an engine quicker on startup. The quicker an oil circulates through an engine when started, the less time the internal components are moving without lubrication. This equates to less engine wear and a longer engine life.

In addition to performing better when an engine is first started, they also perform better at higher temperatures because they are less volatile. Fluctuating temperatures have less effect on a synthetic oil’s viscosity as they do on mineral-based oils.

Synthetic oils have less impurities than standard motor oil, which forms large amounts of sludge as it breaks down. This sludge decreases an engine’s efficiency. With less impurities and a consistent molecular structure, synthetic oil can better resist oxidation and will produce fewer deposits.

If you are an eco-friendly consumer, you’ll appreciate that synthetic oils are better for the environment. Unlike traditional motor oils, they don’t need to be drained and recycled every 3,000 miles. Instead, they are designed to be changed anywhere from 7,000 to 15,000 miles, depending on the oil. This is better for the environment, and will save you from running to the mechanic every couple of months.