New Oil, Fluids & Additives

The Best 5W20 Synthetic Oil – Comparisons and Reviews

Searching for the best 5W20 synthetic oil isn’t easy as there are literally thousands of products. Many of them are designed for specific engines and vehicles. To help you make the best decision for your car, we have reviewed the top synthetic oil products from the major brands. Check out our detailed guide for buying synthetic oil.

Best 5w20 Synthetic Oil: Quick Look

Synthetic Oil NameQualityPriceRating
Royal Purple 36520-6PK HPS 5W-20 Synthetic Motor OilA+$$$
Pennzoil 550038331 Ultra Platinum Full Synthetic Motor OilA+$
Mobil 1 120763 Synthetic Motor OilA+$$
Castrol 03083 EDGE 5W-20 Synthetic Motor OilA++$$
Valvoline MaxLife High Mileage Motor OilA++$$

Why 5W20 Synthetic Oil is Superior to Conventional Motor Oil

Synthetic oil provides superior engine protection. Both come from the ground, but that is the only thing they have in common.

  • Synthetic oil removes impurities: It is purified, distilled, and refined. 5W20 synthetic oil keeps your engine cleaner so it runs smoothly.
  • Prevents oil deposits and sludge: Conventional motor oil collects deposits as it goes through your engine, and sludge forms over time. Together, these reduce your engine’s lifespan and performance efficiency.
  • Reduces Wear and Tear: The constant contact, high speed, and extreme weather conditions take their toll on engines. 5W20 synthetic motor oil serves as a protective shield to reduce component wear. 5W20 motor oil also comes with long-lasting wear protection, prolonging engine life.
  • Better Engine Flow in Low Temperature: Oil settles when your car sits for an extended period. The oil starts to flow when you start the ignition, but conventional oil takes longer to smoothly flow in the engine. In cold weather, this process takes more time. 5W20 synthetic oil however, flows quicker and provides protection as soon as your car starts.
  • High Temperature Protection: Engines get hot when running, and driving at high temperature environments doesn’t help. Synthetic oils have been formulated to help engines deal with intense heat and prevent breakdown.
  • Turbo Engine Protection: Cars today use compact engines to be fuel efficient, but they have turbochargers to improve performance. However, turbochargers break regular motor oil more quickly than standard engines. With up to 200,000 revolutions per minute, proper lubrication is necessary. Conventional motor oil cannot handle this and break quickly, causing engine failure. In contrast, 5W20 synthetic oils provide more protection. The end result is your engine produces more power at maximum performance levels.

What is Oil Viscosity?

Viscosity refers to oil’s flow resistance. It is rated at 0°F and 212°F. The first number is right beside the W (winter) and the second number is the viscosity designation. This means a 10W30 doesn’t have as much viscosity during hot and cold temperatures than a 20W-50.

Motor oil gets thinner as it gets hotter, and it thickens as the temperature drops. What you need is motor oil with the proper additives to prevent too much thinning. Motor oil can have different viscosity levels for high and low temperatures.

What are Oil Additives?

Additives maintain or improve oil performance. They also reduce varnish and sludge while preventing engine damage. 5W20 synthetic oils use different additives, and the following are among the most common.

  • Rust/corrosion inhibitors: Protects metal components from moisture and acids
  • Viscosity-index improvers: Reduces oil-thinning
  • Dispersants: Keeps particles in a solid solution to prevent them from turning into acids, varnish or sludge.
  • Detergents: Don’t confuse these with the household detergent. Engine detergents prevent corrosion, rust, and deposits caused by high temperature.
  • Antioxidants: Rising temperatures in engines lead to oil thickening and oxidation. Antioxidants are formulated to prevent this from happening.
  • Friction Modifiers: Friction modifiers minimize engine friction and make the engine more fuel efficient. There are many types of friction modifiers including molybdenum and graphite.
  • Anti-wear Agents: Sometimes film lubrication breaks down, necessitating the need for anti-wear agents to protect metal surfaces.

How to Change Oil in Your Car

The following video is a step by step guide for changing oil in your car.

5 Best 5W20 Synthetic Oils

Synthetic Oil NameQualityPriceRating
Royal Purple 36520-6PK HPS 5W-20 Synthetic Motor OilA+$$$
Pennzoil 550038331 Ultra Platinum Full Synthetic Motor OilA+$
Mobil 1 120763 Synthetic Motor OilA+$$
Castrol 03083 EDGE 5W-20 Synthetic Motor OilA++$$
Valvoline MaxLife High Mileage Motor OilA++$$

Royal Purple 36520-6PK HPS 5W-20 Synthetic Motor Oil

Royal Purple 36520-6PK HPS 5W-20 Synthetic Motor Oil-5be9f9481920c

The Royal Purple 36520-6PK HPS 5W-20 Synthetic Motor Oil is available in different sizes (1 quart, 1 quart case of 6, 1 quart case of 12 and 5 gallons). While sizes vary, they all provide optimum protection for the motor. When used on a regular basis, the oil boosts your engine’s torque and horsepower for superior performance.

The Royal Purple motor oil is an all-in-one solution that cools, cleans, and lubricates engines. The formula is compatible with different types of motor oils, including recycled oils, hybrid (synthetic and conventional), bio-based, diesel, synthetic, and conventional.

The Royal Purple has a SAE 5W-20 weight, meaning its rating is 20 at regular temperatures and the viscosity is 5 in cold weather. The Royal Purple is full synthetic so there is no crude element here.


  • Reduces engine wear
  • Provides oxidation stability
  • Compatible with different types of oils


  • Not formulated for motorbikes

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Pennzoil 550038331 Ultra Platinum 10W-30 Full Synthetic Motor Oil

Pennzoil 550038331 Ultra Platinum 10W-30 Full Synthetic Motor Oil-5be9f9497e621

The Pennzoil 550038331 Ultra Platinum 10W-30 Full Synthetic Motor Oil uses PurePlus Technology, which allows it to produce low viscosity, even at -13° F to -40° F. This means the engine will exert less effort in oil pumping. Compared to other API Group II and III oils, the Ultra Platinum gives you greater viscosity control.

The Ultra Platinum uses a special formula that transforms natural gas into high quality motor oil. With regular use, your car’s mileage may get a boost up to 550 miles annually while shielding your engine from power failure. The formula produces 99.5% pure base oil, cutting down wasted oil.

The Ultra Platinum is also effective in reducing engine noise, and regular application fast tracks engine starts, even in cold weather.


  • Increases vehicle mileage
  • Offers superior viscosity control
  • Makes engines run quietly


  • Sometimes leaves deposits in car engines after 50,000 miles

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Mobil 1 120763 Synthetic Motor Oil

Mobil 1 120763 Synthetic Motor Oil-5be9f94ad97cf

The Mobil 1 120763 Synthetic Motor Oil contains 100% synthetic oil to prevent sludge and deposits from building up in the engine. The oil’s formula also provides reliable performance in cold temperature, and you get long term benefits as it reduces system component pressure.

Its frictional properties are advanced, enhancing fuel economy and viscosity control. The Mobil 1 5W-20 also provides superior protection against wear and tear. In addition, its oxidation and thermal properties enhance stability, regardless of driving style.

The Mobil 1 5W-20 is compatible with supercharged, gasoline, multi-valve fuel injected and turbo-charged engines used in trucks, light vans, SUVs and passenger cars. It is also cost-efficient, as you can go 5,000 miles or so before another oil change.


  • Easy to use
  • Cuts down engine stress
  • Superior performance in cold temperatures


  • Not suitable for aviation and two-cycle engines

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Castrol 03083 EDGE 5W-20 Synthetic Motor Oil

Castrol 03083 EDGE 5W-20 Synthetic Motor Oil-5be9f94c63edd

The Castrol 03083 EDGE 5W-20 Synthetic Motor Oil has been formulated for maximum performance and engine protection. The Edge exceeds ACEA B1, ACEA A1, API SN, ILSAC GF-5 standards, which results in superior deposit control. The oil also provides protection against oxidation and wear tear.

The motor oil meets the performance requirements of Ford, Chrysler and other vehicles, and it can adapt to your engine’s changing environment. It also gives your engine full protection so performance is always at a high level.

This is possible because Castrol uses a custom formula. The Edge doesn’t burn quickly, which results in faster performance. Lastly, the oil reduces engine noise, a common issue when driving at low temperatures.


  • Provides optimum protection for engines
  • Works with a wide range of vehicles
  • Leads to smoother and quieter engine with regular use


  • The cap protector is a bit hard to remove

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Valvoline MaxLife High Mileage Motor Oil

Valvoline MaxLife High Mileage Motor Oil-5be9f94e16790

The Valvoline MaxLife High Mileage Motor Oil is specially designed to satisfy high mileage engine requirements and it contains antioxidants that keep oil from breaking down. The formula also stops deposits from forming and sludge from clogging the engine. There are also detergents which keep old engines in good condition.

The MaxLife motor oil bonds to eliminate deposits and sludge, and you get extra protection from engine wear. It also has seal conditioners to avoid oil leaks. MaxLife is a combination of premium and synthetic oils with friction modifiers, anti-wear additives, and cleaning agents.

Aside from high mileage engines, the oil also works for new and rebuilt engines. Whether you change oil every 5000 miles or more, you’ll get optimum performance.


  • Has antioxidants that reduce engine wear and tear
  • Works on old engines with high mileage
  • Keeps car engines quiet


  • Protector cap is tight

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The Best Oil Overall

Any of the 5W20 Synthetic Oils reviewed here are manufactured by known and respected brands, and they’re all high quality. But for overall performance and dependability, GarageChief has to give it to Royal Purple 36520-6PK HPS 5W-20 Synthetic Motor Oil. A lot of motor oils produce the same results, but the additive technology in Royal Purple really makes a difference in performance.

Its phosphorous and zinc additives do a good job of reducing engine wear, and you can feel the difference in the engine horsepower. More than anything else, Royal Purple allows you to get maximum mileage without the need for frequent oil change, saving your money and time.