Does Engine Oil Get Thicker When Hot? Find Out Today

Contrary to popular belief, not all motor oil gets thicker as temperatures increase. In fact, it actually thins out during this period which is why you should change your oil on a regular basis.

The thing is that oil that’s too thick can lead to problems like poor fuel economy and excessive wear on your car’s engine. This could result in a shorter lifespan for your vehicle or even cause it to break down sooner.

It is safe to say that engine oils consist of two components: base stock and additives. Typically, these are petroleum or synthetic chemicals, while the additives enhance its lubricating and cleaning abilities.

The ideal motor oil would never change viscosity with temperature. That is why the Society of Automotive Engineers developed a VI (viscosity index) to measure an oil’s resistance to changing viscosity at certain temperatures.

Thinner engine oil can assist your engine in flowing more easily during cold weather, helping it to start more easily. This is especially true of synthetic oils with smaller molecules that can navigate through tight spaces more readily.

When your engine gets too hot, it may be tempting to use thinner engine oil at this point. That is why following the manufacturer’s instructions for your vehicle is so important; they will help determine what’s best suited for your vehicle needs.

Continue Reading: Does Engine Oil Gets Thinner Over Time

How Does Temperature Affect Viscosity in Motor Oil?

Does Engine Oil Get Thicker When Hot

Viscosity of motor oil plays an integral role in engine performance and fuel economy. Your vehicle owner’s manual will provide recommendations on which viscosity range works best for your car’s age, power output and climate.

In addition to oil viscosity, your vehicle’s manufacturer may suggest additives to increase lubricant strength and reduce wear, such as friction modifiers, anti-wear agents, etc. All of these elements should be added to the base oil for efficient engine protection and performance.

When the temperature of a lubricant or oil changes, its viscosity also changes, leading to higher friction and reduced engine efficiency. This is especially common during temperature surges when your vehicle needs to work harder than usual to stay cool and run efficiently.

Lubricants tend to thicken in cold temperatures and thin out when temperatures rise. Thinner oils may impede your engine’s performance and result in reduced fuel economy.

Higher viscosity motor oil can protect engine wear and damage by creating a strong, thick film that keeps metal parts separated within the engine and prevents them from touching each other. Lower-viscosity oils on the other hand reduces friction, allowing engines to start more quickly in cold conditions.

Viscosity of an oil depends on its molecular size and structure. Mineral oil molecules vary, while synthetic oils are chemically engineered for uniform sized molecules with fewer impurities – this allows them to flow at lower temperatures than conventional oil, which must be refined from crude.

FAQs – Frequently Asked Questions

Q. How do I know if my engine oil is too think

When your car engine is too thick, you will start to experience symptoms such as poor fuel economy, a hard time starting in cold weather as well as shorter engine life.

Q. Should I use thicker oil in an older engine?

As the mileage on your vehicle begins to rise you may start to face issues with oil pressure due to age and wear and tear. In this case, the most effective way to improve oil pressure is to use a thicker oil since these oils are known to have a heavier weight base.

Q. Does thicker oil burn more gas?

There is no doubt that the thicker the oil is, the more energy it will take to pump that oil, which uses fuel. So, yes it will eventually burn more gas.


You might be asking yourself this question does engine oil get thicker when hot? Well, it is safe to say that it actually gets thinner whenever it becomes hot. It is best to keep in mind that When the oil is too thick, it affects your car from starting in cold weather and this is because the thick liquid is unable to properly lubricate all the essential parts of the engine.