Why is lubrication important in engines and machinery?
Lubrication is the lifeblood of mechanical systems. It reduces friction between moving parts, dissipates heat and prevents deposit build-up within engines, transmission gearboxes, axles and bearings.
Lubricants create protective films that minimize wear and allow smooth motion.
Proper lubrication allows:
- Extends component life by minimizing wear.
- Improves fuel efficiency by reducing energy lost to friction.
- Ensures smoother, quieter operation.
- Reduces maintenance costs and enhances safety.
Why do I need to change oil and how often should I do this?
You should change your oil and filter at or before the end of oil-change intervals indicated by your vehicle manufacturer. These are based on distance travel or time. Regular oil changing helps to keep your engine oil in good condition and provides the best protection for all of your engine components.
What should be considered when changing engine oil?
Changing your oil is more than just draining and refilling — it’s about selecting the right oil and ensuring proper service:
- Follow the vehicle manufacturer’s recommendation. Check your owner’s manual for the specified oil type, grade and viscosity.
- Consider climate and driving style. Extreme cold or hot weather and heavy-duty driving may warrant different viscosity grades.
- Check labels for certifications. Choose oils that meet API or ACEA standards and the correct SAE viscosity rating.
- Inspect and replace the oil filter and its gasket/O-ring. A faulty or misaligned filter can cause leaks.
- Look for beneficial additives. Detergents, dispersants and corrosion inhibitors help keep engines clean.
- Keep records and stay on schedule. Regular oil changes (typically every 5,000 – 10,000 miles or according to the oil life monitor) maintain oil quality and protect your engine.
- By adhering to these guidelines and using Hexon’s quality lubricants, you’ll maximize engine protection and longevity.
How do I choose which oil is appropriate for my car?
Car-owner handbooks will give you a minimum oil specification. However, you may wish to upgrade to a better engine oil specification. Choosing the correct engine oil for a vehicle depends on:
- The car’s type – a high-performance car needs higher performance oil.
- The car’s age – a lot is expected from new technology engines: High performance coupled with fuel efficiency. Advanced oils have been developed to help keep pace with increased engineering demands. For example, modern cars have blow-by-gas recirculation that can cause extreme oxidation in old-technology oils and sensitive exhaust gas after-treatment devices that can be poisoned by inappropriate oils.
- The driving environment – modern motorway driving and heavy stop-start traffic requires higher quality oils to prevent increased engine wear and tear.
What is the difference between synthetic oil and mineral oil?
- Mineral oils are refined from crude petroleum. Natural contaminants are removed, but they still flow more slowly through the engine and require more frequent changes. They are a low-cost option suited to older engines and application.
- Synthetic oils are produced through complex chemical transformations and contain fewer impurities. Their benefits includes:
- Excellent flow at low temperatures and stable viscosity at high temperatures, which helps protect engines during cold starts and extreme heat.
- Longer oil change intervals, less deposit formation and reduced engine wear.
- Improved fuel economy and extended engine life.
- Semi-synthetic oil mix mineral and synthetic base stocks; they offer better performance than straight mineral oil but not as much as fully synthetic oils.
- Always follow the oil type recommendation by your vehicle manufacturer.
What is the difference between monograde and multigrade oils?
A monograde lubricant, SAE 40 for example, is one that performs well in moderate to hot temperatures but not at low and cold temperatures. A multigrade lubricant, SAE 20W50 API SN for example, is one that has additives such as the viscosity index improver and pour point depressant which leads to a better and effective performance in cold climates and low temperatures as well as warm climates and high temperatures. These additives basically prevent formation of large crystals in lube oil molecules which makes the oil more fluid at low temperatures. This allows the oil to perform optimally in both winter and summer conditions
What is viscosity and viscosity index?
Viscosity is the most important characteristic of almost any lubrication product. It is the measure of the fluidity at different temperatures.
- When the viscosity is too thin, the lubricant film will be squeezed out from the moving metal surfaces resulting in metal-to-metal contact, hence causing more wear to the engine.
- When the viscosity is too thick, it will not travel into the small areas where it is needed. Additionally, it will require excessive pumping force, causing undue wear on pumps and excessive heat built-up. Furthermore it will not permit easy cranking of any engine.
Viscosity of base oils is most commonly stated in terms of Saybolt Viscosity. This states the time in seconds it takes 60 milliliters of oil to flow through a small diameter tube at a certain temperature. This is expressed in Saybolt Universal Seconds (SUS) at either 37.70 Celsius (= 100° F) or 98.80 Celsius (= 210° F), such as 200 SUS @ 37.70 Celsius or 45 SUS @ 98.80 Celsius. The metric system expresses viscosity in centistokes (cSt) or in SI units (mm2/s) at Celsius temperature. The exception in the measurement of oil viscosity is at low temperatures. In this case, a ‘Cold Crank Simulator’ (CCS) is used to determine the viscosity which is usually reported in centipoises at -10 to -350 Celsius.
What are the different grades of baseoils?
There are 5 different types of base oils: Group I, Group II, Group III, Group IV and Group V.
- Group I
This is the least refined type of petroleum base oil and it is produced by a process called Solvent Refining. It consists of conventional petroleum base oils.
- Solvent refining
- Contains less than 90% saturates
- Sulfur content is 0.03% or greater
- Viscosity Index is between 80 and 120
- Temperature range: 0-65 degrees Celsius
Group II
This is petroleum base oil refined even further by partially using Hydrocracking. The process removes all impurities in the base oil which gives the oil a lighter color.
- Partial Hydrocracking
- Contains 90% saturates or greater
- Sulfur content is 0.03% or less
- Viscosity index is between 80 and 120
Group III
This is the best grade available of petroleum base oil. It is produced completely by Hydrocracking.
- Process is completely done by Hydrocracking
- Contains 90% or more saturates
- Sulfur content is 0.03% or less
- Viscosity index 120 or greater
Group IV
These are what the industry refers to as Synthetic base oils which are made of Polyalphaolefins (PAO) through a process called synthesizing. These oils are much more stable in extreme heat and cold conditions. They have very stable chemical compositions and highly uniform molecular chains. Group IV base oils are becoming more common in synthetic and synthetic-blend products for automotive and industrial applications.
Group V
Any other type of base oils that is not a part of group I to group IV is considered a group V base oil. This includes naphthenic oils, polyalkylene glycol (PAG), biolubes and esters. These base oils are also synthetic.
What additives are usually found in engine oil?
Additives are insoluble compounds and/or active ingredients which are added to the above base oils. They change or improve the lubricant properties through chemical or physical action.
Chemically acting additives:
- Detergents
- Dispersants
- Anti-oxidants
- Anti-wear additives
- Corrosion inhibitors
Physically acting additives:
- Viscosity Index (VI) improvers
- Anti-foam additives
- Pour point depressants
- Friction modifier
Here are the categories of key additive ingredients and why they’re important:
- Viscosity-index improvers: Reduce the oil’s tendency to thin with increasing temperatures
- Detergents: Unlike the household type, they don’t scrub engine surfaces. They do remove some deposits, primarily solids. But their main purpose is to keep the surfaces clean by inhibiting the formation of high-temperature deposits, rust and corrosion.
- Dispersants: Disperse solid particles, keeping them in solution, so they don’t come together to form sludge, varnish and acids. Some additives work both as detergents and dispersants.
- Anti wear agents: There are times when the lubricating film breaks down, so the anti wear agents have to protect the metal surfaces. A zinc and phosphorus compound called ZDDP (zinc diakyldithiophosphate) is a long-used favorite, along with other phosphorus (and sulphur) compounds
- Friction modifiers: These aren’t the same as anti-wear agents. They reduce engine friction and therefore improving fuel economy. Graphite, molybdenum and other compounds are commonly used.
- Pour-point depressants PPD: Just because the 0° F viscosity rating is low doesn’t mean the oil will flow readily at low temperatures. Oil contains wax particles that can congeal and will reduce flow, hence these additives are added to prevent it.
- Antioxidants: With engine temperatures being pushed up for better emissions control, the antioxidants are needed to prevent oxidation (and, therefore, thickening) of oil. Some of the additives that perform other functions also serve this purpose, such as the antiwear agents.
- Foam inhibitors: The crankshaft whipping through the oil in the pan causes foaming. Oil foam is not as effective as a lubricant in full-liquid form, so the inhibitors are used to disperse the foam bubbles.
- Rust/corrosion inhibitors: Protect metal parts from acids and moisture
What is pour point and flash point?
Pour point is the lowest temperature at which the oil will pour. This is very important for engine oils and other lubricants operating at low and extremely low temperatures. The pour point is directly related to the type of crude used and it’s wax content.
Flash point is the temperature at which, approximately 70ml of oil will “flash” when exposed to an open flame. This can be anywhere from 132°C to 327°C. This is usually an indicator to the volatility of the oil and is a very important factor in engine oils and their consumption rate.
Why does engine oil degrade or spoil?
Engine oil degrades over time due to several factors:
- Heat: Extreme temperatures changes oil viscosity and can break the oil down. Above 80 °C, oil begins to form deposits and sludge; above 100 °C, it breaks down rapidly and loses its lubricating properties.
- Oxidation: Oil molecules react with oxygen, leading to thickening, sludge formation and increased in acidity.
- Contamination: Particles, debris and water enter the oil, causing abrasive damage and chemical reactions.
- Mechanical stress: Shear forces in the engine can break down oil molecules, reducing viscosity and lubrication effectiveness.
Prevent degradation by following recommended oil change intervals, using high-quality oils and ensuring proper filtration. Regular oil analysis can also help detect degradation before it causes damage.
What do the numbers mean on motor oil?
The first number of a multi-grade oil designates the ability for the oil to be pumped and flow at colder temperatures; the “W” stands for winter. Thus, a 0W oil will be able to flow faster and get to critical engine components better than a 5W or a 10W oil; especially in extreme cold conditions and at engine start-up.
The second number is the viscosity measurement value at engine operating conditions. This viscosity number is crucial for proper lubrication and protection of your engine.
Why does my engine oil turn black?
- New oil is typically golden or light brown. As it circulates, it collects combustion by-products and becomes amber or dark brown — a normal sign of aging.
- Dark oil often contains suspended particles and still lubricates effectively, but it should be changed soon.
- Oil that has turned black has accumulated too many contaminants, has lost much of its lubricating ability and should be changed immediately.
- Milky or frothy oil is a red flag because it indicates coolant contamination; seek professional help.
Some additives in motor oil are more susceptible to darkening in the presence of heat than others. Additionally, normal oxidation can darken oil too. Oxidation occurs when oxygen molecules interact with oil molecules and cause a chemical breakdown, just like how oxygen causes a sliced apple to change to a darker color. Oil can be very, very dark (black even) and still be effective. However, as a general rule: New, clean oil is amber in color. As engine oil gets darker, it can indicate a) high heat, b) contaminants, or c) the presence of additives that cause the oil to darken during normal use.
Why is my engine oil dropping?
Oil levels can drop for two primary reasons:
- External leaks: Worn gaskets (valve-cover, oil-pan or timing-cover), a loose drain plug, or faulty oil-filter gaskets/O-rings can allow oil to leak. A damaged oil pan or worn crankshaft or camshaft seals can also cause leaks. Watch for oil spots under your vehicle and address leaks promptly.
- Internal consumption (burning oil): If oil is entering the combustion chamber due to worn piston rings, valve seals or a damaged head gasket, the engine can burn it without visible leaks. Symptoms include blue-tinted exhaust smoke and a burning smell. A malfunctioning PCV (positive crankcase ventilation) valve may also allow oil to be drawn into the intake. Seek a mechanic if oil consumption is excessive.