1) What does Viscosity mean, is high or low viscosity better?
Viscosity is a measure of a fluid’s resistance to flow. It describes the internal friction of a moving fluid. A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction. A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion.
The best viscosity for a particular application depends on the nature of the application and is determined by three factors:
- Speed: The higher the speed the thinner the oil,
- Temperature: The higher the temperature the thicker the oil,
- Load: The higher the load the thicker the oil.
2) Why is multi-grade oil better than mono-grade oil? Is multi grade oil more expensive?
For most applications multigrade oil is the preferred option since it flows more readily at start-up and maintains lubricity at operating temperature. Multigrade oil is more expensive than monograde since it is formulated with a viscosity index improver or viscosity modifier to enhance the viscosity characteristics of the oil.
3) How often should I check the oil in my car/ machine?
This depends on the application and could be anything from daily to weekly or monthly. For severe applications operators are required to check the oil before start of shift and even in some instances during the shift.
4) What is the difference between automotive gear oils and transmission oils?
Automotive gear oils intended for Hypoid Differentials are formulated to be very “slippery” to lubricate the hypoid gears effectively. Synchronized Transmissions are fitted with synchronizers to allow light and easy gear shifting. Synchronizers use friction to match the speed of the components to be engaged during shifting. Slippery gear oils can reduce the friction between the mating synchronizer surfaces and thereby effecting synchronizer operation negatively.
5) What is base oil and what does it mean to me as the end consumer?
Base oils (also known as base stocks) are specially refined lubrication grade oils used to manufacture finished lubricants. Base oils make up a significant portion of the finished lubricant, from around 75% in automotive engine oils, to 99% in some industrial oil products. Therefore, base oil contributes significant product properties. Base stocks are either mineral based or synthetic based. Most motor oils were mineral based until the late 1990s when Synthetics became more widely available at more affordable prices.
The American Petroleum Institute (API) has categorized base oils into five categories. The first three groups are refined from petroleum crude oil. Group IV base oils are full synthetic (polyalphaolefin) oils. Group V is for all other base oils not included in Groups I through IV. Generally synthetic base oils have better qualities than mineral base oils but they are also more expensive.
6) Do you use different engine oils for petrol and diesel automotives?
There are different oil specifications petrol and diesel engines. For instance the American Petroleum Institute (API) classify oils for petrol engines under the “S” (Service) categories and oils designed for diesel-engine service fall under API’s “C” (Commercial) categories. There are multifunctional oils available in the market that is suitable for both petrol and diesel engines.
7) What is a general-purpose lubricating grease and what applications can it be used for?
To maximize grease lubrication effectiveness, minimize cost and minimize risk of application-induced failure, lubricant manufacturers have made an effort to formulate greases that cover a variety of automotive and industrial applications. These applications range from slow to high speeds, and from low to high loads. A general purpose (GP) grease is designed to meet a broad range of requirements.
It is grease manufactured to medium consistency with a medium viscosity base oil and medium wear, washout and oxidation resistance properties. Essentially, it is a product designed to fit the largest possible cross-section of grease lubricated components.
8) Does the colour of lubricating grease have any significance?
The colour of lubricating grease has very little if any significance pertaining to the performance of the grease. The colour of grease is generally determined by the raw materials used to manufacture the product. General purpose grease will in most instances be brown in colour. Dyes may be added to the grease to differentiate it from other greases. Certain additives may have an influence on the colour of grease. Graphite and Molybdenum disulphide for instance will result in a dark grey/black colour.
9) Is Hydraulic oil safe for my skin?
Hydraulic oil and all lubricating oils for that matter are not safe for the human skin. Oil may cause irritation, dermatitis and even cancer. Most oils contain additives. Some of these additives may worsen the conditions mentioned above. Worst of all is used oil since it may contain metal particles, acids and other hostile contaminants
10) What are the general storage guidelines for lubricants?
Lubricants are best stored under cover in a cool, dry, clean environment away from direct sunlight. If drums are to be stored outside the drums should kept on their sides with the bungs in the 3 and 9 o’clock positions. Oil containers should never be left open once the seal is broken. Different lubricants have different shelf lives but it is good practise to keep storage time less than 12 months.
For this reason it is best to use the First-In, First-Out (FIFO) method. This method simply requires the storekeeper to use the oldest lubricants that were put into the storage system first and the newest lubricants put into the storage system last. This will help ensure lubricants do not accidentally exceed their recommended shelf life.
11) How often should I change the oil in my car?
You should follow the change interval as recommended in the owner’s manual of your vehicle provided you use the quality oil recommended by the manufacturer. The manufacturer may recommend reduced service intervals for harsh operating conditions such as high ambient temperatures or dusty environments.
12) Do I need to top-up the oil in my engine between services?
The engine oil level should be checked regularly and topped up if required to prevent damage or even engine failure. It is normal that a small amount of the oil the engine is burnt away in service. Different manufacturers have different consumption figures for their vehicles but a rule of thumb is that an engine in good condition can consume up to 500ml of oil every 1,000 kilometers). However, frequent top-ups are no substitute for an oil change.
13) Can I mix two different types of engine oil?
In an emergency situation, you may mix engine oils since oil starvation is much more damaging than mixed oil. Lubricants are always formulated to meet the requirements of various OEM (original equipment manufacturer) and international classifications – API, ACEA, etc. However, there are many ways of formulating a specific type of lubricant. Mixing two oils that have equivalent properties will not pose a serious problem, but final performance of the mixture cannot be guaranteed. All engine oils available on the market (petrol or diesel, mineral or synthetic) are generally mixable but the blending of two oils qualities reduce the performance of the oil in your engine.
14) Will aftermarket additives improve the life and performance of my engine?
The answer is NO if you use high-quality engine oil. Reputable engine oils have been tested by international standard organizations and OEMs making it suitable for the recommended drain interval without adding any aftermarket additives. Furthermore, adding supplemental additives to the engine oil may well disturb the delicately balanced chemistry of the engine oil which will reduce the performance of the oil. For this very reason, most OEM engine oil warranties are voided when aftermarket additives are added to the engine.