10w30 vs 20w50 Engine Oil: Know The Actual Difference Now

The battle of a thin and a thick engine oil is pretty old. Several questions had been raised on their act and their traits even answered to those.

10w30 vs 20w50

Here you will get to know two of the thin and the thick oils that happen to determine vehicles’ performance. One is the thin 10w30 oil and other is the thick 20w50 oil.

Both the oils have different purposes as they come with different formulations and characteristics. Despite being synthetic blends, they are not interchangeable when it comes to uses. So, if you are wondering what makes one different from the other, then this article would help you out.

I have explained all the factors so simply in this 10w30 vs 20w50 article that you can easily pick the ideal one at the end of this write.

What Is 10w30 Engine Oil?

Valvoline Advanced Full Synthetic SAE 10W-30 Motor Oil

10w30 refers to the multi-grade engine oil that’s pure synthetic blend. The viscosity of the oil is 30 at high temp that goes down to 10 at lower temp.

Since 10w30 is on the thinner side, it tends to flow quickly when you run the vehicle in colder region. Plus, it lowers exhaust emissions, reduces internal drag, lessens consumption, takes less power from the engine, and increases engine responsiveness in such weather conditions.

If you have a car, SUV, light truck or van that uses petrol or diesel engines, then 10w30 oil would be a great pick.


  • The kinematic viscosity is 10.4 mm2/s at 100° Celsius.
  • The pour point is -42°C.
  • The flashpoint is 232°C.
  • The density at 15.6°C is 0.859 g/ml.


Ideal For Latest Engines

10w30 oil helps the new strokes of the new engine work properly.

Slows Down Engine Wear

The risk of engine damage becomes higher when your vehicle is exposed to temperature change and harsh road conditions. For this, 10w30 engine oil comes with zinc anti-wear additives that help slow down engine wear. The metal contents offer a high heat resistance so that they reduce strains on the motor.

Protects Against Sludge And Deposits

10w30 engine oil features detergent additives that keep the engines clean. This way, it works to remove sludge buildup and varnish deposits that are caused by oxidation.

Ideal For Cold Starts

At lower temperatures, the thinner oil offers a great protective coating that makes it less prone to thickening. As a result, it helps engine start fast. That’s why, it is generally preferable for vehicles that move in colder regions.


Not For Hotter Climate

10w30 will not remain stable if you run the vehicle in hotter region than recommended. The heat can lead to oil burning and excess engine wear.

Not For Old Engines

Vehicles tend to consume more engine oil as they age. So, if you use thin oil in old engines, it will cause more oil burning than thicker oil.

What Is 20w50 Engine Oil?

Castrol 03095-3PK GTX 20W-50 Conventional Motor Oil

20w50 is also a multi-viscosity synthetic oil but heavier. The viscosity of this oil is rated at 50 at high temp and it drops down to 20 at lower temp.

As it is known as a thick oil, it performs excellently in hotter climates. Due to its density, you will find it more resistant to thinning when it heats up.

The oil makes an ideal choice for the vehicles or motorcycles using air-cooled engines.


  • The kinematic viscosity is 20.5mm2/s at 100° Celsius.
  • The pour point is -3°C.
  • The flashpoint is 230°C.
  • The density at 15°C is 0.878 g/ml.


Delivers Race-Level Protection

The oil contains high level of zinc, phosphorus and molybdenum contents. Hence, it offers high performance and race-level protection on the highway or race track.

Boosts Horsepower Output

20w50 provides engines with improved sealing between cylinder wall and piston ring. As a result, it helps reduce friction and maximize torque and horsepower of the vehicle.

Protects Against Sludge And Deposits

This oil also comes with added detergents that work to clean up the engines by removing high-temp oil sludge, deposits and other contaminants.

Ideal For Old Engines

As engines age, the clearance between the tight mechanical parts increases. Thus, using thicker oil fills the gaps and prevents engine from getting damaged. Not just that, old engine burns less thick oil than that of the thinner one.


Not For Colder Climate

The oil is surely not suitable for use in cold regions as the thickness will increase at low temperatures. As a result, the lubrication will not be proper, causing the vehicle to deteriorate.

Not For Latest Engines

Thick oil is not good for latest engines. It can obstruct the flow to sensitive areas such as cylinders that rely on quick oil pressure.

Comparing 20w50 Vs 10w30

20w50 Vs 10w30


10W30 and 20w50 have different SAE rating that makes them perform better at different temperatures. While the less viscosity offers better flow in colder regions, higher viscosity provides better sealing effect in hotter regions.

Uses In Vehicles

The thinner oil is ideal for vehicles that use petrol or diesel engines while the thicker oil is compatible with vehicles using air-cooled engines.

Bottom Line- Which One Is For You?

It depends on where would you be using the car. If you are living in tropical region, then opt for 20w50 engine oil. Being an extremely viscous oil, it would provide you with more protection at higher temp. Not just that, it helps prevent leaks in older vehicles.

In case you run your vehicle at lower temp, then using 10w30 engine oil would be great. Although it is not the thinnest but quite thinner than the others, making the engine start quick in frigid climate. You will also find it ideal for latest engines since it offers smooth lubrication.

More Related Content:

Leave a Comment