5w20 vs 5w40

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When choosing motor oil, the primary concern is its viscosity, which decides whether it is ideal for use in vehicles or not. For example, 5w20 and 5w40 are the best picks, as per the top auto manufacturers. Also, 5w20 and 5w40 have similar low-end temperature viscosity that make them suitable for vehicles in cold climates.

5w20 vs 5w40

There are many engine oils out there that have different formulations to meet the specifications of different vehicles. However, 5w20 and 5w40 motor oils have the right formulation of synthetic oils and additives, thereby making them superior oils for most modern engines.

Also, 5w20 and 5w40 have varying viscosity for the high-end temperatures but are still optimal for high operating temperatures. Hence, if your vehicle is compatible with both these motor oils, you need to decide upon one that is probably the best. Again, refer to this 5w20 vs 5w40 article to choose the right one among the two.

5w20 Specifications

5w20 is top-notch engine oil that has the potential to offer efficient engine protection. This is because the components within the internal combustion engine handle some critical functions and demand utmost protection.

An old car engine with small oil deposits in a yellow car

And, 5w20 has the optimal viscosity, thickness, and weight to lubricate those critical components, thereby ensuring seamless performance. Moreover, this engine oil can help protect your vehicle engine for the next 10,000 miles before it signals for a change.

5w20 oil, with the numbers 5 and 20 in its name, denotes the level of viscosity. So, for example, the number ‘5’ denotes the viscosity of this oil at low-end temperatures.

And the number ’20’ denotes the viscosity at high temperatures. Furthermore, this oil meets the latest industrial standards, ensuring that it provides the required level of performance.

In addition, the thermal and oxidation stability make this engine oil a worthy pick. Apart from that, the low-temperature capability is also an impactful perk that promotes its use in cold climates.

The wear protection potential of this oil is superior, with efficient additives. Furthermore, it consists of active agents for cleaning the sludge-buildups and promoting dirt dispenses.

In fact, 5w20 is an ideal pick for gasoline and diesel engines too. It is also preferable for FI, supercharge and turbocharge engines currently being used in light trucks, light vans, SUVs, and passenger cars.

5w40 Specifications

5w40 is yet another popular synthetic oil with quality stocks and additives. The formulation of this oil intends to offer collective performance enhancement, wear protection, and meets all the industry standards.

Furthermore, this oil has the potential to enhance the performance of racing engines. Hence, most race car manufacturers recommend it. 5w40 is an ideal pick for almost all types of vehicles, driving styles, and driving conditions.

5w40 oil has numbers within its name that state the viscosity rating of this oil. For example, the number 5 denotes the viscosity of this oil at low temperatures. And the number 40 denotes the viscosity at high temperatures.

A man inspecting the engine of a car

Also, it is a better alternative than most of the other conventional engines. This is why it has been compared to several oils similar to it, such as the compatibility of 10w30, viscosity of 10w40, and as well as the operating temperatures of 15w40.

Irrespective of whether your vehicle is operating within usual or severe operating conditions, this engine oil has the ideal viscosity, thickness, and weight to endure it all.

In addition, 5w40 also possesses some proactive cleaning agents to take care of the sludge build-up and deposits within the engine. Thus, it helps resist the oil aging aspects, which promotes protection for drain interval.

Apart from that, 5w40 also reduces the hydrocarbon pollution aspects to suppress the harmful impact upon the environment. All of the vehicle engines that demand high-performance require proficient engine oil like 5w40. Also, it is an apt consideration for gasoline supercharge engines, diesel FI engines, and turbocharge engines.

5w40 offers better friction control over the engine components, thereby extending their durability. It means that the components rubbing against one another are under control and are properly gliding with oil lubrication. In this way, the gears and other dynamic components experience less wear and tear over time.

Similarities of 5w20 and 5w40

  • They both have active agents to assist the cleaning process.
  • Also, both these oils have thermal & oxidation stability to offer.
  • Both of these oils have similar low-end temperature viscosity of ‘5’.
  • These oils are synthetic-based oils with superior lubrication capability.

Differences of 5w20 and 5w40

  • The high-end viscosity of these motor oils are different in both these oils. For example, it is 20 for 5w20 oil, whereas it is 40 for 5w40 oil.
  • 5w40 is less effective at high operating temperatures in comparison to 5w20.
  • The flashpoint for 5w20 is 234 degrees C, whereas for 5w40, it is 231 degrees Celsius.
  • The kinematic viscosity for 5w40 at 100 degrees Celsius is 13.7mm2/s, whereas for 5w20, it is 8.6mm2/s at 100 degrees Celsius.

Major Distinguishing Factor

The major distinguishing factor between 5w20 and 5w40 lies within their viscosity indexes. For example, the viscosity index of 5w20 stands at 163, whereas, for 5w40, it is 176.

Pistons inside a car engine

When to Use 5w20?

5w20 is preferable for both gasoline and diesel engines that demand high-end performance. Moreover, 5w20 is an ideal oil for engines running in both hot and cold regions.

Therefore, check the manufacturer specifications for the vehicle, and validate the compatibility. If it permits the use of 5w20, then you are good to go!

When to Use 5w40?

If you are looking for even thicker oil, then 5w40 can be a good option. Also, 5w40 is much preferable for vehicles that operate for long distances at a single stretch.

Hence, it means that 5w40 has a higher potential of handling extreme operating temperatures. So, consider this factor for using this oil type.

Final Verdict

Both these oil types are best in serving their purpose! However, some factors will promote the choice of one among the two. In fact, the most common factors that help in choosing one of the oils are the operating temperature and pricing.

Here, 5w20 might be a bit expensive option than 5w40 due to its low viscosity at high temperatures. You might want to check out 5w30, as well, to see what is the difference between them. So, make your choices accordingly, based upon the given specifications!