20w50 engine oil advantages and disadvantages

Motor oil is the most vital thing in the engine as it can break or make a car. Using the wrong oil can lead to severe damages, which as well be costly to repair. Therefore, having the correct information about a particular oil will save you a lot.

So, what is 20W50 engine oil, and where can you use it?

20W50 engine oil is a high viscosity, and heavy-duty engine oil meant for gasoline and diesel engines. This oil is most suitable for use as a motorcycle oil or racing oil. 

What 20W50 mean

20W50 engine oil is heavy duty and high viscosity motor oil commonly used in high-temperature conditions. The numbers in the oil 20W-50 accord to the (SAE) Society of Automotive Engineers format for a high-grade oil with the “W” standing for winter. 

Unlike single-grade motor oils, Multigrade motor oil such as 20W-50 gives an excellent operating temperature range. The 20W-50 oil is thick with high viscosity and does not thin quickly. Although it is not a common oil viscosity grade, it is recommended for most automobile cars. 

The numbers 20W50 are the motor oil’s viscosity per the American Society of Engineers. This is the oil’s viscosity or thickness. 20W denotes how fast the engine will start at cold temperatures or cold, while the 50 is the oil’s thickness when the engine has run for a while. This oil is relatively thick and dense.

What 20W 50 engine oil is used for

20W-50 engine oil is a popular engine oil primarily used in medium to large gasoline and diesel engines, aviation vehicles, and motorcycle bikes. The oil is also used as a high-temperature driving and racing oil because of its excellent resistance to thinning. 

Most oils often break down when exposed to high temperatures. Still, the 20W-50 can withstand high temperatures because it is meant for engines that reach extremely high temperatures to lubricate the car parts such as pistons and prevent friction, engine sludge, and varnish deposits.

This oil makes a better sealant if used on suitable engines. It offers enough cushioning, which protects the engine parts against friction. This, therefore, leads to extended engine life and reduced wear and tears. 

Note that this oil is thicker and only recommended for some vehicles. Therefore it is important to always refer to the car manufacturer’s manual before using this heavy-duty oil on your car. You can as well consult your mechanic before switching oils. 

Suitable temperatures for use

The 20W50 engine oil is appropriate for use in warmer temperatures when the high-temperature conditions cause the oil to thin. Moreover, the oil is useful for cars used for high-stress activities like pulling trailers and hauling in hot temperatures.

Although this oil is is best for warmer conditions, the temperature range of this oil type is between -20 °C and +40 °C or -4 °F to 105 °F.

Vehicles used on 

The 20W50 engine oil is suitable for small or large gasoline engines, diesel engines, aviation vehicles, and motorcycles. The oil is also ideal for liquid and air-cooled motors. However, this depends on the recommendations for the particular car. 

Using the oil on modern vehicles can be havoc because modern-day engines are non-tolerant due to complicated technology like Variable valve timing mechanisms. The oil is too thick and cannot flow to sensitive parts like VVT/VANOS, multivalve cylinders, or anything that depends on instant oil pressure. 

Advantages of 20W50 engine oil

  • It has a high viscosity, making it ideal for use in older car models and extremely high temperatures. Never, the thicker oil prevents leaks which are common in old vehicles. 
  • The oil’s high viscosity offers better cushioning and protection against friction between metal parts. Therefore has excellent anti-corrosion and antiwear properties. 
  • The oil offers the best sealing capabilities because of its thickness, hence better sealants than a thinner oil.
  • 20W50’s properties enable it to offer an extended engine life, hence saving on costs. 
  • The oil is designed with excellent antifoaming features and shear stability
  • 20W50 engine oil prevents varnish deposits and sludge from forming on the engine pistons
  • The oil has excellent cold cranking abilities where the multigrade thickness is specified. 
  • The oil has a high resistance to thermal breakdown, which can occur due to engine temperatures.

Disadvantages of 20W50 engine oil

  • Since the oil is thick, it is not ideal for modern-day cars and engines that require thinner oil.
  • In cool temperatures, the oil becomes too thick, which affects its circulation in the engine. This means it is not ideal for use during cold seasons or weather. 
  • The oil can reduce engine power, poor oil economy, and harmful emissions from the engine.
  • The oil might affect the timing system or throw it out of sync. The timing belts or chains fail to function due to the oil’s increased thickness. The reason why this happens is that most modern variable valve timing systems depend on the oil pressure. Once the highly viscous oil is used, the oil pressure goes up, damaging the lifters, piston rings, and cam bearing. These symptoms will be blue smoke emanating from the exhaust, lifter tick, and cam noise. 
  • The oil can lead to premature wearing of the oil pumps because of the thickness, which the pump was not meant for. This means that the pump will wear out faster. If your car has a turbocharged engine, you will note that it might fail earlier since the turbo bearings that receive oil might fail because of the thickness. 
  • The oil might also affect the car’s gas mileage; there will be sludge build-up within the camshaft or crankshaft and then make the bearing fail, resulting in the engine’s catastrophic failure.


20W-50 engine oil is a heavy-duty engine oil with a high viscosity. The oil is best for use during warm weather or on automobiles that require high heat.

However, the oil was not meant for modern-day cars but can work best with the older ones. That is why most older cars had an extended engine life of up to one thousand miles. If you are unsure whether to use this oil on your car or not, it is essential to check your car manual or consult your car’s mechanic.

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