Oil In the Engine: What Does It Do?

Engines must have an oil film separating the moving parts to prevent the engine from destroying itself.

Having regular oil changes and keeping the engine oil topped off is a critical aspect of engine maintenance.

What Are Engine Oil’s Main Functions?

Lubrication

Engine oil practically eliminates friction between moving parts in the engine. The hardest working lubricated parts are the connecting rod and main bearings, followed by the piston rings and cylinder walls, and then the camshafts with their bearings.

The hardest working lubricated parts are the connecting rod and main bearings, followed by the piston rings and cylinder walls, and then the camshafts with their bearings.

– Richard McCuistian, ASE Certified Master Automobile Technician

Cooling

Given that intense heat is being created inside the combustion chamber, the oil flowing inside the engine also plays a role in cooling down the engine. However, since oil doesn’t pass through a radiator or heat exchanger which cools the oil, the vehicle’s cooling system is still mainly responsible for cooling because it uses a radiator to dissipate the heat collected by the coolant.

Cleaning

Combusting fuel produces soot, acids, and combustion byproducts that typically get ejected from the exhaust. However, sometimes these materials can pass through gaskets and piston rings. Engine operation also creates tiny pieces of abrasive metal as a result of metal components rubbing against each other.

Without oil to carry these contaminants, soot, and combustion byproducts can create deposits that would hinder engine performance and efficiency, while the tiny pieces of abrasive metal can also accelerate wear and tear. Regularly changing your engine oil is important because after 7,500 to 10,000 miles, your vehicle’s oil can have too many contaminants and becomes less effective.

How Does Oil Work in a Car?

When oil is pumped through the engine under pressure, it leaves behind a film that makes the surface slippery. This film significantly slows down engine wear because it prevents metal-to-metal contact between components. These occur between valve stems and their guides. Metal-to-metal contact also occurs between the pistons and cylinder walls.

Engine oil doesn’t just sit inside your engine and slush around except in the oil pan, which is the reservoir that contains the engine oil. The oil pump draws oil in, pressurizes it through the oil filter and then through a series of passages called the “oil gallery.” The oil then drains back into the oil pan where the process starts all over. Some elements of the engine aren’t lubricated with pressurized oil. They depend on splash oil lubrication, such as the cylinder walls where the pistons travel with their sealing rings.

Vehicles can either have a wet sump or dry sump oil system in their vehicle. Wet sump systems typically have much larger pans at the bottom of the engine and only a single oil pump. The oil pans in dry sump systems are shallower, with a separate reservoir and two or more oil pumps. A dry sump system has several distinct advantages, such as a lower center of gravity because it uses a shallower oil pan and flexible oil capacity, which can lead to improved cooling. It also allows the engine to sustain high g-forces in corners without losing oil pressure.

Oil is extremely important for an engine. It allows it to function for decades and travel hundreds of thousands of miles without needing much maintenance. This is why it’s important to keep your engine topped off with oil and change its oil on a regular basis.

Where to Get New Motor Oil for Your Vehicle

Now that you know more about what oil does in your engine, it’s easy to see why it’s so important. If you don’t periodically replace your vehicle’s engine oil or you don’t top it up when it’s running low, your vehicle can have issues like overheating, accelerated engine wear, and more. It’s also best to keep a spare bottle of motor oil around for emergencies.

Luckily, CarParts.com offers a wide range of different motor oils on our easy-to-navigate website. What’s more, we make ordering as convenient and as easy as possible. Once you’ve picked the type of oil that suits your engine, you can proceed through our safe and convenient checkout. We’ll ship your order of motor oil straight to your door. It’ll be quick too, thanks to our strategically located warehouses. Your order can arrive in as fast as two working days if you’re within the continental US and order by 12 PM ET.

Don’t wait until you’re in desperate need of motor oil before buying some. Have a spare quart or two ready just in case. Buy new motor oil at CarParts.com today.