FAQ Lubricants

Can I add additives in oil?

The components of our oils have been proportioned to reach an optimum result. Adding an additive may create unnecessary and maybe even harmful blends. Certain manufacturers ban additives in oils.


Can I put in my gear-box the same oil as in my engine?

The answer to this question depends on the technology used. Although some older vehicles allow the same lubricant to be used for both the engine and the gearbox, new vehicles require different products for each. Follow the manufacturer's recommendations for the best results.


Can I use diesel engine oil in a petrol engine, and vice-versa?

Petrol and diesel engines have different lubrication requirements. During development, lubricants undergo a number of tests; some are common to diesel and petrol engines, and others specific to one or the other type. At the end of this process, they are awarded an API or ACEA/CCMC compliance standard. These specifications characterise the acceptable functioning of the lubricant in each type of petrol or diesel engine. Lubricants for four-stroke engines usually comply with both petrol and diesel specifications. For example, an API SJ/CF lubricant meets petrol specification SJ and diesel specification CF. But this does not necessarily mean that it will perform in the same way in both petrol and diesel engines. This is why Elf has developed specialised ranges, optimised either for petrol or for diesel.


Can I mix two different types of oil?

Lubricants are always optimised to meet the requirements of international classifications (API, ACEA). However, there are many ways of formulating a specific type of lubricant. Mixing two oils that have equivalent properties will not pose a problem, but final performance cannot be guaranteed. All market oils (petrol engine or diesel, mineral or synthetic) are mixable. However, a blending of two oil qualities lower the overall quality.


Can I use car engine oil in my motorcycle?

No, because motorcycle four-stroke engines do not operate under the same conditions as those of cars (higher engine rpm and temperature). The engine lubricant can also be used to lubricate the gearbox and the clutch, which requires a formula with EXTREME-PRESSURE ADDITIVES. On the other hand, passenger vehicle lubricants contain DETERGENT ADDITIVES with a high ash content. In motorcycle engines, these cause deposits to form on the valve train and the piston crowns, which can result in valve burning or piston perforation.


What causes oil pressure to drop?

During normal vehicle operation, oil is vital to ensure leak tightness between the combustion chamber and the crankcase. The oil pressure indicator shows how well this is being done.

An unusual drop in oil pressure can result from either lower engine oil viscosity due to dilution by fuel (injector problem or use at low load); too little oil in the lubrication system (due to an oil leak, excess oil consumption, or failure of the oil circulation pump); or even mechanical part wear.


Does the oil have to be topped up?

The engine oil level should be checked regularly to prevent incidents. A small amount of the oil that circulates in the engine is always burnt (an engine in good condition consumes between 0.2 and 0.5 litres of oil every 1,000 kilometers), but successive top-ups are no substitute for an oil change.

Accordingly, it is natural that an engine consumes a small amount of oil, which can be offset by top-ups between oil changes. However, excessive need for top-ups can be an indication of mechanical problems (leaks, etc.).


What does a lubricant do?

Lubricants are vital for the correct operation of your engine:

• cooling engine hot spots and moving parts
• ensuring that engine parts remain clean
• ensuring leak tightness between engine parts
• protecting the inner surfaces of the engine against corrosion

Additives, including detergent additives, dispersant additives, and additives against corrosion, can also help.


How can you judge lubricant performance?

Product labels provide a considerable amount of information about lubricant performance.


What are the advantages of a quality oil?

A good quality oil provides motorists with a number of benefits:

• easier cold start and reduced wear (20-30% of engine wear occurs between startup and the time the engine reaches optimal temperature)
• longer engine life
• fuel savings as a result of reduced friction of moving parts and better engine performance


Why choose a synthetic oil?

Semi-synthetic and synthetic oils are made from non-conventional bases using sophisticated chemical processes, which give special properties to the finished product. First, the high level of viscosity of the base oils used gives the finished lubricant remarkably stable viscosity whatever the temperature. This property is one of its major advantages over mineral oils, made from conventional bases which require a greater number of additives in order to improve viscosity. The stability of lubrication in all temperatures guarantees optimum efficacy in the cold starting phase, which is particularly demanding on the engine as well as under conditions of extreme heat.

Synthetic-based lubricants show greater resistance to oxidation, which gives them longer effective life - thus guaranteeing longer engine life. The use of non-conventional bases, finally, permits the elaboration of more fluid lubricants, without being more volatile; resulting in a reduction of oil consumption.

Therefore, choosing a synthetic-based oil is a technologically-advanced choice, for greater efficacy, longevity and controlled oil consumption.


What are the advantages of a multigrade oil?

Multigrade oils provide better engine protection at low and high temperatures than monograde oils, in that they maintain optimum viscosity over the engine-operating temperature range.


Which oil should we use in turbo-compressed vehicles?

In order to fulfil the lubrication and shaft cooling needs of the turbo-compressor, oil must answer to very strict criteria. The shaft reaches a very high temperature, due to the proximity to exhaust gases. Oil must lubricate the shaft continuously, otherwise the high temperatures would permanently damage it and the temperature would then rapidly reach very high levels.

These conditions mean the oil has to offer a considerable detergent property - that is, an important resistance to oxidisation and deposit formation - but especially a very high thermic stability. The use of SYNTHETIC oils is therefore the most recommended solution in these conditions. Turbo-compressors are characteristic of diesel engines, as it is very easy for petrol engines to reach the same power level by other means, such as electronic injection, cylinder head multi-valves, etc.


Are all oils adapted to vehicles equipped with a catalytic converter?

The answer is clear: no.

This challenge has been met by the CATALYTIC CONVERTER, whose role is to complete the combustion of the exhaust gas just before they escape into the atmosphere. In order to respect the environment, oils must offer a high lubrication property, better detergent and dispersant properties as well as a low sulphur and phosphorous content. These properties are essential for oils that will be used in vehicles equipped with catalytic converters. The use of a non-adapted oil can damage the catalytic converter. Synthetic lubricants are highly recommended because of the intrinsic properties of their base.


Why change the oil?

The oil change is an essential operation in maintaining a vehicle in top condition.

You should change your vehicle's oil regularly:

• especially if you travel through larger highway networks and a higher annual average of kilometres
• due to the deterioration caused by city driving conditions
• because multigrade oil allows you to 'save' between 1.5% to 3% of fuel than monograde oil
• because lubricants collect particles of internal and external pollution (e.g. carbonic matter, particles of worn metal)
• because an oil's efficacy diminishes due to dilution by water and fuel, oxidation, the consumption of additives, as well as shearing
• because, when the vehicle is not being used for several hours, the engine oil sinks in the crankcase so that, on start-up, it takes time to reach all parts of the engine that need to be lubricated again. Since a multigrade oil is more fluid at low temperatures, it reaches the various engine components more quickly than a monograde oil, thereby reducing wear on start-up


How often should oil be changed?

• At least once a year
• The frequency recommended by the manufacturer may be modified according to the lubricant used, vehicle used (country, city, motorway), thermal and mechanical requirements
• Never drive with an oil level below the minimum mark on the dipstick. Below this mark, there is not enough oil, thus causing more rapid circulation of the fluid and accelerated wear on the oil
• It is recommended to check the level regularly every 1,000 km and especially before a long trip


Can you chose another viscosity grade when changing oil?

Yes, you have to adjust the viscosity according to the conditions of the vehicle's usage, the environment and the climate conditions.


What type of oil packaging should I choose?

If you carry out your own oil change, you will need a 5-litre container, given that the average capacity of the sump is 4.5 litres.

If you are topping up between oil changes, a 1-litre container will suffice: it is practical, easy to use and cheaper.


Can I stock oil? Will it deteriorate?

In closed containers stocked at over 0°C, your oil will retain all its qualities. However, it is recommended that opened containers be well closed in order to avoid contamination by water.


What should I do with used oil?

Pour it in the back garden? That's against the law!

While the quality of oils and their biodegradability have improved, these products are filled with particles of pollution which can be harmful to the environment. You may deposit your oil in special containers which can be found in the parking lots of supermarkets or at your neighbourhood garage.


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