Frequently Asked Questions

This section will answer you queries about Shell Helix, Specifications, Changing Oil and The right oil change interval for your car.

About Shell Helix

Changing Oils

Specifications

The Right Oil Change Interval for Your Car

Shell Helix lubricants minimise contact between parts-in-motion, protecting them from mechanical wear and so reducing the loss of energy caused by friction. They also prevent the build up of sludge deposits that can interfere with the normal function of mechanical elements.

Shell Helix will also:

Shell Helix engine oils have been designed by Shell technologists to our own specifications, and significantly exceed industry standards. They are tested under the extreme conditions of the Ferrari F1 racing team - in fact, every drop of oil that goes into Ferrari's F1 engines is Shell Helix. So you can enjoy the same performance from your lubricant that the Ferrari team relies on.

Synthetic lubricants are made up of molecules that have been modified under complex chemical processes and allow for enhanced performance under extreme conditions of temperature, pressure and forces. By exploiting these properties, it is possible to improve engine protection, especially at high (and also very low) operating temperatures, lower emission via lower evaporative losses, lower fuel consumption via lower frictional losses and extend the oil change interval. Mineral lubricants are composed of molecules present in crude oil that are separated in the distillation process at a refinery.

Generally, most mineral based (non-synthetic) motor oils are miscible with one another. However, the effectiveness of the combined additive in the motor oil may be questionable. As for synthetic oils, they should be treated with more caution as some synthetics are not fully miscible with mineral oils, or with other synthetics.

When upgrading from one type of oil to another, e.g. from Shell Helix standard to Shell Helix Ultra, it is best to do a complete oil change so as to obtain maximum benefit from the switchover.

A liquid that has a relatively high resistance to flow can be described as viscous. For example, water has a low viscosity compared with honey, so in this case honey has a higher viscosity than water under the same temperature. A good quality lubricant keeps its viscosity steady under different temperature and usage conditions for a longer period of time.

Can we check oil viscosity without sending it to a laboratory?

Checking oil viscosity with your fingers at room temperature can be misleading as viscosity is temperature dependent. Furthermore, the rate of viscosity variation differs from oil, particularly if you are comparing monogrades to multigrades.

Moreover, used engine oil will "feel" thicker than new oils because of the contamination's present in the used oil.

Lubricants that are able to maintain their performance in high and low temperatures are called multigrades. Two numbers define them. The first (followed by a W) indicates the lubricant's viscosity under lower temperatures. The second and higher number indicates the lubricant's viscosity under greater temperatures. A multigrade lubricant minimises viscosity differences under temperature variations.

No, thick oils may not necessarily be better than thin oils. Good motor oils have to be thin enough to move freely and smoothly through the engine when it is cold, and thick enough to protect the parts when the engine is running and high temperatures are experienced. The best oil therefore is the one that remains stable throughout the wide extremes of hot and cold. Therefore, it is the engine balance quality that matters and not the thickness or thinness of the engine oil.

Motor oil lubricates the car engine. The oil serves to reduce friction, thus allowing the engine parts to move smoothly, and it also protects the parts from wear and tear. Without the motor oil, the engine would seize up. Therefore, the better the quality of the oil, the better the protection for the engine parts and the better the performance of the car.

This is normal. In fact, if the oil does not change colour during use, it is not doing its job. Good engine oils will contain detergent additives that help clean up the engine and in the process cause the oil to turn black. During an oil change, the contaminants picked up by the oil are removed from the engine. If the oil does not turn black after some time, it could be that there are no detergent additives present, and that all the soot and deposits are still clinging to the engine. Hence, in such a situation an oil change would bring out relatively clean oil but the "rubbish" is still stuck within the engine.

The rate of oil consumption is dependent on various factors (not in any order of importance):

The viscosity and volatility (ease of evaporation) are to an extent, factors that affect oil consumption rates. A thinner oil has a higher tendency to be burned up in the engine, especially if the engine runs at high speeds. Volatility is inversely related to viscosity. The higher the viscosity, the lower the volatility, and hence, the lower the oil consumption rate.

If viscosity poses a problem, it is often the choice of viscosity that is the problem. If the engine manufacturer recommends a SAE 20W-50 oil, the usage of a 10W-30 oil rather than a 20W-50 oil may result in a higher oil consumption rate. This however, does not mean that thicker oils are better. Motor oils, which are too thick, will cause other problems, such as loss of power, increased oil temperatures and poorer oil circulation. Therefore, you need to pick oils, which are of the correct viscosity for your engine. Consult your car manual if necessary.

Most engines have oil control rings which prevent or limit the amount of oil going into the combustion chamber where it is burnt up. The extent to which oil flows into the combustion chamber depends on the engine design and also on the condition of the piston rings and cylinder walls. Thus it is important to note that different engines do have different oil consumption rates.

In addition, older cars tend to have larger clearances, and more tendency for oil leakage. It is therefore common to use higher viscosity oils for such engines to help control lubricant consumption. If this does not help, the engine should be checked. An overhaul may be necessary.

Higher speeds and higher temperatures may increase the oil consumption rate. This could be due to the fact that at higher speeds, more (excess) petrol is sprayed into the engine. This has the effect of diluting the viscosity of the oil, and hence the lower viscosity will result in higher oil consumption rates. Similarly, higher engine temperatures will reduce oil viscosity.

If the correct oil viscosity has been chosen, it is unlikely that the rate of oil consumption is higher than that specified by the car manufacturer. Oil consumption rate is more a function of the engine conditions rather than oil properties.

When referring to new oils, the colour of the oil is of no consequence. The colour of the oil is determined by the colour of the oil is determined by the colour of the base and the additives. Thus, it has no bearing on the performance of the oil. Performance can be judged by the relevant performance specification (e.g. API SJ).

Shell Helix motor oils come fully formulated with additives and hence, there is no need to put in more additives. Typically, motor oils would have about 15% w/w of additives content. Additives are used in our lubricants to give them the necessary performance attributes, which meet or exceed the accepted industry performance levels (e.g. API, ACEA). Such performance specifications are accepted by engine manufactures as a guarantee of performance level. On the other hand, no additive or engine treatment company guarantees that lubricants treated with their additives will meet accepted industrial standards such as API SJ.

Shell's additives are carefully balanced to ensure that they work in harmony and do not impede each other's functions. Off-the-shelf additives and engine treatments are "chemicals" and should such products be used, Shell cannot guarantee that there would not be any adverse reaction with additives already present in the oil. If you choose to use such products, the supplier of that product should be liable for any damages that may occur.

While the "claim" that some engine treatments make may be true, they however do not always reflect the whole truth. For instance, it is possible to claim lower engine friction, but what may have been omitted is the fact that in some cases more engine damage could occur and filters/oil lines can be blocked by these "treatments".

No engine manufacturer actually recommends the use of additives or engine treatments. Equipment manuals will usually specify the viscosity grade and API/ACEA specification of the oil. Thus, the usage of products that have not been tested against any of these industry specifications is not recommended.

First of all it is necessary to check that the consumption is anomaly, considering the kind of engine, its age and the driving conditions to which the engine is exposed. Faults could be caused by a leak in junctions or seals, wear to pistons or cylinders or deposits limiting the lubrication of some surfaces.

The colour of an oil has no special meaning, but depends of many factors such as base oils, additives, crude oil and the refining process. Oil may turn a darker colour after use because it contains a number of suspension particles - the reason for this is that oil cleans the engine of particles and other deposits produced by the high temperature combustion, keeping the particles in suspension to avoid depositing them on the engine's surface.

Several factors influence when you should top up or change your engine oil. Take a look at our "Tips for Motorists" and "The right oil change interval" for your car for information on when and how to change your engine oil.

Lubricants vary in their use and quality. Some are only suitable for particularengines, while others can only be used in certain weather. Even two oils optimised for thesame engine and weather conditions can have vastly different levels of performance.Universal criteria to describe oil performance and usage are therefore used.

The main three classification boards are:

Society of Automotive Engineers (SAE) - defines oil according to its viscosity.Oil can be monograde or multigrade, depending on its viscosity performance at varioustemperatures. Multigrade oils are able to maintain their performance in high and lowtemperatures and are defined by two numbers. The first (followed by a W) indicates thelubricant's viscosity under lower temperatures. The second and higher number indicates thelubricant's viscosity under greater temperatures.

American Petroleum Institute (API) - classifies oils according to their capacityto protect the engine. The letter S is used for petrol engines and the letter C for dieselengines (more relevant for diesel commercial vehicles). The letter that follows the S orthe C indicates the degree of performance and protection, with A the lowest and X highest.Some oils can be used in petrol and diesel engines, so their classification is stated asSJ/CF or CF-4/SJ.

Association des Constructeurs Europeens d'Automobiles (ACEA) - similar to theAPI, with the difference that while the API is based on American Engines, the ACEA isbased on European engines. The ACEA also uses letters to denote classifications, and isespecially relevant for diesel passenger cars.

Ques: I have always changed my motor oil at 5000 Km for my last car. I've recently bought a new car and am surprised to see that the recommended oil change interval has increased to 10000 Km. Is this right?

Ans: There has been considerable pressure on carmakers to help their customers by extending the service intervals of modern cars. One important effect of this trend has been to increase the oil drain period UNDER NORMAL DRIVING CONDITIONS, from typically 5000 Km up to 7500 or 10000 Km, and even longer with some cars - PROVIDED YOU USE THE PREMIUM GRADES OF OIL WHICH ARE NECESSARY FOR NEWER TECHNOLOGY CARS.

Ques: Surely this longer oil drain interval will increase the level of stress on the oil in my car?

Ans: Longer oil drain intervals will increase the stress on your oil, particularly in modern engines with low oil consumption. However, modern high-performance engine oils such as Shell Helix Ultra are carefully designed to provide performance exceeding latest international engine oil specifications. These oils have been rigorously tested against the demanding standards set by major OEM's such as Ferrari, BMW, Ford, Mercedes-Benz, Peugeot-Citroen, Porsche, Rover and Volkswagen. Therefore, these oils can be trusted to provide reliable engine protection when used according to the recommendations in the vehicle handbook.

Ques: It says in my vehicle handbook that if I drive under severe conditions, I should change my oil more frequently. What exactly does the term "severe driving conditions" mean?

Ans: "Severe driving conditions" refer to the following:

Many people believe that the most severe driving condition is high speed motorway driving, particularly if carrying a heavy load. Whilst this type of driving can place considerable stress on the oil, driving patterns which include a significant amount of travelling under "stop and go" conditions, making frequent trips of less than 10-15 km or often leaving the engine idling, can be even more severe.

In particular, "stop and go" driving can result in greatly increased engine wear because of the high number of cold engine starts experienced. (One major OEM records the number of times the ignition is switched on as a factor in determining when the oil is ready for charging. The more cold engine starts carried out, the more rapidly the oil change warning light will come on.) Under all of these severe conditions you should change the oil more frequently than the normal drain period that is indicated in the vehicle owner's handbook.

Ques: From what you say, it sounds like most people drive under severe driving conditions!

Ans: Yes, that is quite true. In an urban city, there are a significant number of motorists who make trips that are less than 10 Km. Engine wear will likely increase if these short trips are made with frequent "stop and go" driving conditions.

Ques: If I don't change my oil frequently, will I notice the difference?

Ans: No, but your engine will! Not changing your oil on a regular basis can significantly reduce the level of protection provided against wear. An engine oil acts as a reservoir for all by-products when the fuel burns, including soot, water and acidic material, as well as unburned and partially burnt fuel. At the same time, the stress placed on the oil during engine operation gradually depletes the components, which determines the oil's performance. Changing the oil on a regular basis ensures that the right balance of components is present in the oil, and also removes waste materials which might otherwise result in increased deposit formation, corrosion of metal components and increased wear.

Ques: Since an oil change is meant to remove contaminants, can't I extend my oil change and just change the filter more regularly?

Ans: Though it is true changing the filter will help remove contaminants, it cannot remove all the contaminants. Some of the contaminants such as acids, water and fuel are "dissolved" in the oil. These particular contaminants cannot be removed by filtration and the only way of removing them is by changing the oil. In addition, it is important to note that there are other reasons for oil change and these cannot be addressed by merely changing the filter more frequently.

Ques: If my driving pattern falls into the severe categories, such as

Should I change my oil more frequently to give maximum protection to my investment?

Ans: You should follow the recommendations in the vehicle handbook. In the absence of a precise recommendation in the owner's vehicle handbook, contact us for advice on the right oil change interval for your car. If you think your driving pattern falls in the severe category, we recommend changing the oil at half the interval specified for normal driving conditions.

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