Proper lubrication is the lifeblood of all vehicles. It reduces wear on the components and ensures effective heat dissipation for a friction-free driving experience.
Unsure whether to use grease or oil?
The right choice between grease vs oil depends on the component — how difficult it is to access, its exposure to moisture, and how hot it gets.
However, there’s more to know before making the choice.
To help you avoid improper lubrication, we’ll discuss the benefits of each lubricant, which components they’re best for, and the consequences of using the wrong type.
This Article Contains:
- Automotive Grease vs Oil: What’s the Difference?
- How Are Oil and Grease Made?
- Grease vs Oil: What They’re Used for?
- Grease vs Oil: Which One Is Better?
- How to Choose the Right Lubricant for Your Car
- What Are the Consequences of Using the Wrong Lubricant?
Automotive Grease vs Oil: What’s the Difference?
Grease and engine oil are automotive lubricants for car and engine parts. Both share common ingredients, including a base oil and several additives.
The primary difference is that lubricating grease contains a thickening agent in addition to the base oil, which affects its consistency and viscosity. This makes grease thicker than engine oil, which is more of a liquid lubricant.
Apart from lubrication, both grease and oil serve the following purposes:
- Control and maintain the engine temperature
- Ensure the engine remains dust-free
- Protect the engine against moisture damage and corrosion
- Prevent intense friction between metal parts and delay engine wear
NOTE: Yellow or brown grease aren’t automotive greases; they are byproducts of food production. Yellow grease comes from used cooking oil, whereas brown grease is waste collected from a grease trap or interceptor.
Now that you have a general understanding of these lubricants, let’s examine how manufacturers produce them.
How Are Grease and Oil Made?
Here’s some information on the production process for grease and oil:
A. Grease
Manufacturing grease entails:
- Selection and heating of base oils: The process begins with selecting and heating base oils, which can be mineral, synthetic, or bio-based, depending on the intended application. The base oils are heated to facilitate mixing with other components.
- Mixing of the thickener: Typically made of metallic soaps, thickeners are prepared by reacting fatty acids with alkali metal hydroxides in a process known as saponification. The thickener is blended with the heated oil to alter the base oil viscosity. Then, the mixture is dehydrated to prevent water from affecting performance.
- Use of additives: Additives are incorporated to enhance the grease’s ability to withstand extreme temperatures and pressures.
B. Engine Oil
Producing engine oil is a multi-step process that includes:
- Extraction: The process begins with finding and extracting crude oil from underground reservoirs using drilling rigs.
- Refining: Crude oil undergoes fractional distillation, segregating into different fractions based on boiling points. Then, impurities like polycyclic aromatic hydrocarbons are removed.
- Additive blending: Producers mix various additives to enhance the base oil’s performance. These include base oil viscosity modifiers, pour point depressants, and foam inhibitors.
But what exactly are they made for?
Grease vs Oil: What They’re Used for?
Both lubricants perform similar functions, but certain applications demand the special use of either grease or oil.
Let’s see what each type of lubricant is better suited to:
A. Grease Lubrication
A grease lubricant has a higher viscosity than oil. Thanks to the addition of synthetic grease additives and a thickening agent, grease lubrication is ideal for:
- Heavy-duty protection: Wheel bearings and other metal components require a strong barrier against intense friction.
- Hard-to-reach engine parts: For continuous lubrication of car machinery where you can’t install an oil circulation system (e.g., a clutch release bearing or U-joint).
- Sealing engine parts exposed to contaminants: Lubricating grease is a better seal against water and dust contaminants as it’s a thicker oil with a sticky consistency.
- Lubrication of sliding metal parts: Grease lubricant doesn’t flow as fast as oil. Therefore, it acts as a dry lube and better protects the metal surface of sliding parts against friction while ensuring smooth operation.
- Specialty grease applications: Polyurea grease is best for permanently sealed components (e.g. universal joints and chassis fittings), whereas lithium grease works for wheel bearings. Calcium grease is ideal for marine applications. These greases contain specific grease additives that make them favorable for certain jobs.
- Lubrication of worn-out parts: The grease additives provide stronger protection for worn seals than oil. This is because worn seals and bearings retain a dry lube better than oil.
- Noise reduction: Grease lubricant better absorbs noise than oil due to its thick consistency.
B. Oil Lubrication
Certain applications will require mineral oil or synthetic oil rather than grease:
- Lubrication of fast-moving parts: Since oil is a liquid lubricant of thinner consistency, it’s better for fast-moving engine machinery (e.g., pistons) than grease lubrication.
- Cooling down engine parts: Motor oil is far better for cooling down engine components and ensuring heat transfer from oiled bearings.
- Lubrication against extreme friction: Oil works best for lubricating car parts that experience extreme friction, like oiled bearings.
- Protection at high temperatures: Grease separates due to oxidation at high temperatures. This makes oil a better choice if the metal surface experiences extreme heat.
Next, we’ll break down the advantages of grease and oil.
Grease vs Oil: Which One Is Better?
Here are some of the benefits you can expect from grease and oil:
A. Advantages of Automotive Grease
The thickening agent responsible for grease consistency gives it the following advantages over engine oil:
- Excellent start-stop performance since it’s a dry lube that doesn’t drain when the engine is off
- Improved control over leakage for worn seals and bearings
- Better seal against contaminants to keep the engine clean
- Independent functioning since it doesn’t require a filter or pump to remove contaminants
- Long-lasting protection and continuous lubrication when it comes to water resistance
- Less frequent maintenance; you don’t need to refill it as often, and you’ll require smaller amounts
B. Advantages of Engine Oil
Engine oil is ideal for high-speed and fast-moving applications. Regardless of whether it’s mineral oil or synthetic oil, it has many benefits:
- Provides better heat transfer for improved temperature control
- Doesn’t separate at high temperatures, unlike grease
- Consumes a lower amount of energy while operating
- Doesn’t cause incompatibility issues with other synthetic oils as it doesn’t contain a thickener
- Gives cleaner, mess-free handling; it’s easier to change and drain out
- Lasts longer for oiled bearings (roller and ball bearings)
- Offers an extended lifespan through monitoring and replenishment
- Is safe to handle and dispose of with minimal environmental impact
With these benefits in mind, you’re probably wondering how to decide which lubricant is right for your vehicle. Read on to find out.
How to Choose the Right Lubricant for Your Car
Whether you need oil or grease will depend on the component you want to protect. Let’s look at some examples to better understand.
A. When to Use Grease
You should use grease for:
- Car equipment in contact with moisture: Thicker grease is better for metal components like wheel bearings and ball joints, as oil lubricant can easily wash away when exposed to water.
- Long-lasting applications: A specialty grease seals against water and corrosion, making it better for worn-out machine parts.
B. When to Use Oil
Meanwhile, oil lubricant is best suited for:
- High-temperature engine parts: Components like pistons and liners require engine oil lubrication, as oil can circulate heat around the engine, cooling it down.
- Gearboxes: As grease may easily bleed under high pressure, gearboxes require gear oil for lubrication.
Grease and oil have multiple uses, but that doesn’t mean they’re interchangeable. Using the wrong lubricant can have detrimental effects.
What Are the Consequences of Using the Wrong Lubricant?
If you choose an inappropriate lubricant, it can lead to improper lubrication. This will increase the wear and tear on machine parts, reducing their lifespan.
Proper lubrication is important, especially for engine components. If your lubricant doesn’t provide enough heat dissipation, your engine will likely overheat. This can significantly damage your engine and possibly result in you needing to replace it, which will be extremely costly.
So, how can you avoid this?
Your vehicle’s manual is an excellent guide for determining which lubricant to use for different car parts. However, you can always contact a professional mechanic if you’re unsure.
You may also choose specially formulated lubricants for specific applications. For example, cooking oil and gun oil are formulated with specific viscosity ranges to suit their jobs.
Lubricate Your Vehicle for a Smoother, Safer Ride
Without proper lubrication, you’ll face an endless road of vehicle problems, from grinding gears to excessive engine heat and more.
However, it’s difficult to know which lubricant each component requires. Moreover, lubricants don’t last forever, so you’ll need regular oil refills and grease maintenance to avoid car problems.
So why not get a professional to advise you on which lubricant to use?
AutoNation Mobile Service mechanics can assess your vehicle and change the lubricants right from your driveway. We’re available seven days a week and offer a 12-month, 12,000-mile repair warranty.