The Important Difference Between ATV Oil and Car Oil

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Using car oil in your ATV might seem like a good idea because it’s usually cheaper and easier to find. However, this isn’t a good choice for your ATV’s long-term health.

In this article, we’ll explain how car oil and ATV oil differ and why these differences matter for your vehicle’s performance and lifespan.

The crucial difference between ATV and Car oil is how they are designed to perform under diverse operating conditions. ATV engines run hotter, under more stress, at higher RPMs, have a smaller oil volume, and don’t have as complex emission equipment as cars. ATVs with a common sump require wet clutch-safe oil. 

Here’s a table highlighting the key differences between ATV and car engine oil:

ATV Engine Oil
Car Engine Oil
Typically lower viscosity for easier flow at lower temperatures and in smaller engines.
Higher viscosity designed for larger engines and higher temperatures.
Contains additives specific to ATV needs, such as anti-wear agents, and may include elements to protect against rust and oxidation.
Additives are tailored for automotive engines, focusing on longevity and higher temperature operation.
Shear Stability
Higher shear stability to withstand the stress of constant gear changes and off-road use.
Optimized for smoother operation in typical driving conditions, less focus on shear stability.
Compatibility with Clutches
Formulated to be compatible with wet clutches commonly found in ATVs.
Not typically formulated for wet clutch compatibility; focus is on the engine only.
Operating Conditions
Designed for the varied and often extreme operating conditions of ATVs, including water exposure, mud, and varying loads.
Designed for more consistent and less extreme operating conditions of road use.
Change Frequency
Often requires more frequent changes due to harsher operating environments.
Longer intervals between changes due to more controlled operating environments.
Thermal Stability
High thermal stability to resist breakdown in varied temperature conditions.
Designed for high thermal stability, but typically in a narrower range of operating temperatures.
Engine Design
Made for smaller engines that often integrate the gearbox and engine, requiring oil to perform multiple roles.
Designed for larger engines where engine oil and transmission oil are usually separate.

Let’s explore how and why ATV oil and car oil is formulated differently and how the varying operating conditions influence the specific properties needed in the oil.

Related: Choosing the Right ATV Oil: What You Need to Know

How Engine Oils are Tailored to Vehicle-Specific Needs

Engine oil serves multiple purposes, like protecting the engine against wear from friction, oxidation, and deposit formation, and helps keep the engine cool.

Cars and ATVs operate under very different conditions, each posing different challenges for their engine oil. Unfortunately, no single oil formula can perform effectively under all these varying conditions.

ATV engine oil gets exposed to a far more severe environment and needs to withstand a broader range of stressors than any automotive oil.

So, how do the oil manufacturers overcome this challenge? They use oil additives such as friction modifiers, viscosity modifiers, and others to tailor customized blends for each application. 

A typical bottle of engine oil consists of about three-quarters of base stock and one-quarter worth of various additives. 

The amount and composition of additives determine how well an oil performs under various operating conditions.

Engine oil blends optimized for cars will not do as good of a job when used in an ATV. Some additives used in car oil are redundant and may even cause harm if used in ATVs. The same applies if ATV oil is used in cars. 

So what unique challenges and conditions are we discussing, and why can’t one oil formula meet them all?

ATVs With a Common Sump Need Wet-Clutch Compatible Oil

A common sump is where the engine, clutch, and transmission all use the same body of oil contained in one shared oil sump. 

Modern cars and most ATVs use separate oils for the engine and transmission rather than a combined design.

However, ATVs with manual transmission and wet clutches usually have a common sump system. In this case, the oil you use must be compatible with all components it touches. More specifically, the engine oil needs to be wet-clutch compatible. 

The problem with using automotive oil in common sump ATVs is that it contains friction modifiers that can cause significant problems when used with wet clutches. The same applies to additives in automotive oils designed to improve fuel economy. 

The additives and modifiers can cause clutch slippage, creating a glazed surface on the clutch plates. This leads to additional clutch slippage issues and premature clutch wear. 

This is why you should never use automotive oil in stand-alone ATV transmissions. 

Wet-clutch compatible oil contains no friction modifiers that could cause the clutch to slip and is labeled “Jaso MA.”

Note that oil for automatic transmissions does contain friction modifiers and is labeled “Jaso MB.”

ATVs Require different Viscosity Engine Oils than Cars

Viscosity is a measure of a fluid’s resistance to flow. Fluids with lower viscosity flow faster, while fluids with greater viscosity flow slower. For example, water has a viscosity of 1.0, while raw honey has 12.200. 

In oils, the viscosity is displayed in a format like this: 5W-30.

  • The first number indicates the viscosity when the oil is cold.
  • The latter number suggests the viscosity when the engine reaches operating temperature.

Conventional automotive engine oils are usually 10W-30 or 5W-20 or similar viscosity ranges. 

ATV engines and transmissions, on the other hand, require oils with a broader viscosity range to work correctly and to provide proper protection and lubrication in extreme cold or heat.  

As an example, my Polaris Sportsman uses 5W-50 viscosity. Other ATV brands typically require oils in ranges from 0W-40 to 10W-40. Please refer to the user manual to discover what viscosity the manufacturer engineers have determined is the ideal viscosity for your particular bike. 

Oil manufacturers use viscosity modifiers to create oils with viscosity numbers optimized for ATV use. These numbers are typically not found in automotive engine oils. 

Using oil with the wrong viscosity can lead to oil consumption and gear pitting, leading to gear failure. 

Another issue with using automotive engine oil in an ATV is the oil’s ability to keep its viscosity stable over time. Cars typically change the oil in shorter intervals, reducing the need for viscosity stability. 

On the other hand, ATVs are frequently left unused for long periods, which demands more from the ATV oil. It must remain effective months later, just as it was when first added.

Related: Oil Change Intervals For ATVs: What You Need To Know

ATVs Run at a Higher Engine Temperature

ATVs regularly run hotter than most cars, with cylinder temperatures ranging from 90 to 200°C (194 to 392°F). When oil temperature increases, it loses viscosity and becomes thinner. Thinner oil does not lube and protects the engine as efficiently against wear.

Another issue with overheating oil is accelerated chemical decomposition, also known as oil oxidation. 

The decomposition rate doubles for every 18°F (10ºC) increase in oil temperature, effectively reducing oil life expectancy by half. 

ATV Engine oils must be formulated to withstand such intense temperatures. 

An ATV Has a Much Smaller Engine and Oil Sump

ATVs have a much smaller oil sump than cars, with only about 1/5th to 1/10th the amount of engine oil in circulation. This increases the importance of the oil’s effectiveness in cooling the ATV.

The smaller ATV engine requires oil formulated for smooth flow through the narrow pathways inside the engine. 

ATV Engines Run at Higher Speeds (RPMs)

Unlike a car, which usually runs at engine speeds between 1500 to 2500 RPM, an ATV often operates at much higher RPM levels.

The main concern with engine oil at high engine speeds is oil foaming. 

As engine speed increases, the mechanical action of the rotating crankshaft causes an increasing amount of tiny air bubbles to begin forming in the oil. 

ATV engine oil and other high-speed engines are explicitly formulated to release this air from the oil as fast as possible, as this helps prevent foam buildup. 

When using the wrong oil, causing foam to build up, the oil lubricating properties are reduced drastically, increasing wear in gears and bearings or possibly causing engine failure. 

Oil foaming can also cause the oil to deteriorate faster.

ATV Oils Require Greater Shear Stability

An oil’s shear stability measures its resistance against change in viscosity caused by mechanical stress or shear. 

When oil with poor shear stability gets exposed to excessive mechanical stress, it gets thinner.

ATVs are regularly used to perform heavy work at low speeds. This creates high tension on the gears and increases the load on the engine bearings. 

The oil film must be strong enough to withstand this tension without collapsing, also known as shearing. 

Automotive engine oil is not designed to withstand high-load, high-pressure operation, at least not to the same degree.

ATV Oil Contains More Corrosion Inhibitors

Most ATV oils contain additives to prevent internal engine corrosion or rust. Corrosion typically happens due to internal condensation if an engine sits for extended periods without being used. 

Most cars are used regularly, if not daily, and thus, oil manufacturers do not emphasize corrosion prevention as much.

Long-term storage corrosion protection is just one of the properties you might miss out on when using car oil in your ATV.

Different Emission Requirements Apply to ATVs Than Cars

Cars use various high-tech emission-reducing components to comply with today’s emissions requirements. 

In most places, these requirements do not apply to ATVs. This means that cars have many complex components you won’t find in an ATV.

ATVs don’t have emissions equipment like cars, so that oil manufacturers can add higher levels of beneficial additives to ATV oil. These additives, like zinc and phosphorus, aren’t compatible with car components. 

Related Questions

Is Car Oil and ATV Oil the Same

Car oil and ATV oil are not the same as they contain different additives and modifiers to give the oils unique properties customized to fit the specific needs and requirements of the two vehicle types. 

Is ATV Oil the Same as Motorcycle Oil?

ATV oil and motorcycle oil have similar properties, but there could be important differences. Using motorcycle oil that meets the JASO specification recommended by your ATV’s manufacturer is likely okay. However, for the utmost safety, it’s best always to use the oil specified by the ATV manufacturer.

Can I Use Car Oil/Engine Oil in ATV

Using automotive engine oil in an ATV can cause immediate or gradual damage over time. The most common issue is caused by using non-wet-clutch compatible automotive oil in a wet-clutch ATV. This can cause clutch slippage and, eventually, clutch damage. 

Related: How to Change ATV Oil at Home: A Step-by-Step Guide

Haavard Krislok
Haavard Krislok
Haavard Krislok is an ATV and off-road enthusiast with a rich background spanning two decades in owning, maintaining, repairing, and utilizing ATVs for farming, logging, and hunting. Outside his professional life as an engineer and project manager, he cherishes recreational trail riding and is the creative force behind, serving as its owner, editor, and content creator.

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