What Happens if You Put 5w20 Instead of 5w30?

Wrong motor oil? Big no-no! Different grades have different viscosities and compositions. Make sure you use the correct weight and type for your car. Else, 5w20 instead of 5w30? Yikes! It can cause your engine some short and long-term problems.

Be aware of these potential issues and save your engine from any damage!

What is Motor Oil?

Motor oil – it’s a lubricant made for an internal combustion engine. It helps reduce friction between engine components. It also helps stop wear and tear and makes the machine more efficient.

So, what is motor oil? And what’s the difference between 5w20 and 5w30? Let’s explore!

Types of Motor Oil

Motor oil is used to lubricate, clean, and excellent engine parts. Types of motor oil include:

  • Conventional, made from refined crude oil, has viscosity ratings from 0W-20 to 40W.
  • Synthetic blend, a mix of conventional and synthetic, offered better fuel efficiency and reduced wear on engine parts.
  • Fully synthetic, 100% artificial, and used for high-performance engines, with higher heat resistance and better engine protection.
  • High Mileage Motor Oil, for vehicles with over 75000 miles. It helps maintain performance, reduces engine wear, and prevents fuel loss, inefficient operation, and increased emissions. It can even reduce engine power and slow acceleration.


Viscosity is key when it comes to motor oil. All motor oils have a rating based on density, which is the resistance when the oil moves in an engine. This rating system uses two numbers, e.g., 5W20 or 10W30.

The first number, 5 and 10, shows how well the oil performs in cold weather. This is called the ‘winter’ grade. The higher the ‘W’ number, the better it works at low temperatures.

The second number, 20 or 30, is how thick or dense the oil is when hot. The higher the number, the wider the oil. A 5W30 oil is good for hot summers and cold winters. It’s thin when cold but thick when hot. 0W20 is suitable for mild weather all year round. It’s thin even in winter but may not be wide enough for long drives.

What Happens if You Put 5W20 Instead of 5W30?

Picking the perfect motor oil for your car’s engine is critical to maintaining it. 5W30 and 5W20 are two common motor oil types. But do you know what happens if you use 5W20 instead of 5W30? We’ll explain the consequences of using the wrong oil in your engine.

Difference Between 5W20 and 5W30 Oil

How Does Viscosity Affect Engine Performance?

Viscosity is a liquid’s resistance to flow. It matters for vehicle engines. It is measured in cS (centistokes) and given as KV 40 (kinematic viscosity at 40 degrees Celsius). Motor oil has two numbers that describe its weight, such as 10W-30 or 5W-20. The W stands for winter, and the lower number shows how thin the oil is when cold. The second number is the thickness when hot.

Using the wrong viscosity has consequences, including:

  • Poor lubrication when it’s cold
  • Varying performance with temperature
  • Faster wear of components
  • Worse fuel economy.

Consult the owner’s manual to get optimal engine performance. If the engine has been modified, 5w30 or 20w50 may be needed for better lubrication and less wear. Remember to check the viscosity with changing temperatures.

What Are the Potential Risks of Using the Wrong Oil?

The wrong oil for your car can have bad results. Three risks you should be aware of:

  1. Damage to internal engine parts. Oil not specially made for your engine can cause damage to bearings, pistons, and rings. It may not give the viscosity or lubrication the engine needs.
  2. Bad performance. Wrong oil could lead to reduced performance from your engine. It won’t lubricate or manage heat properly.
  3. Poor fuel efficiency. Inefficient engine performance leads to lower MPG numbers and higher emissions.

Be sure to check what kind of oil your engine needs. Doing so will help keep your car running smoothly and safely.


The facts show that using 5w20 oil instead of 5w30 oil in your engine is not recommended. It may fit, but a slight difference can significantly affect long-term performance. The wrong type of oil can add extra wear to your engine, reduce fuel economy, and cause costly problems.

To get optimal performance and longer engine life, always use the viscosity of oil recommended by your vehicle’s maker.

Frequently Asked Questions

What happens if you put 5w20 instead of 5w30?

Using 5w20 instead of 5w30 could potentially cause damage to your engine. 5w30 is the recommended oil viscosity for most modern car engines, and using 5w20 oil instead could cause the oil to break down quicker, leading to reduced engine protection. Using the oil viscosity recommended by your car manufacturer is always advised.