Buying And Selecting Motor Oil:Types and Grades

Motor Oil Types

This section gives an overview of the common types of motor oil in the market.

  1. Synthetic Motor Oil

    This is a type of engine oil that is artificially made. Synthetic oils are created using chemical compounds and additives in laboratories with the goal of creating an oil with the highest levels of lubrication and protection for the engine. This oil, due to its superior mechanical and chemical properties, is considered better than the conventional oil. Synthetic oils also flow better at low temperatures and maintain the highest lubrication in high temperatures. However, this type of oil is quite expensive. It is much more expensive than the conventional oil most likely due to the fact that it takes a lot of research and money to create this type of oil.

  2. Synthetic-Blend Oil

    As the name implies, it is a mixture of conventional and synthetic base oils. This type of oil was created to offer some benefits of the synthetic oil while at the same time being more cost effective than fully synthetic oils. Like synthetic oils, this type of oil offers more protection to engines compared to conventional motor oils. Vehicles, like SUVs or Vans, that often carry heavy load benefit from this type of oil.

  3. Conventional Motor Oil

    This is the cheapest type of motor oil. It is derived from crude oil and processed in a refinery. This type of oil is often perfectly suitable for older vehicles. Performance-wise most agree that synthetic oils are better than conventional oil for the modern high specification close tolerance motor. The reason has something to do with the composition/properties of the conventional oil. Conventional oils are more prone to quicker deterioration especially if exposed to higher temperatures because of heavier loads on the engine. The higher the load, the more the engine will work and with this comes more heat being generated by the engine. Conventional oils do not lend themselves to flowing as well as synthetic oils in low-temperatures hence it takes a little bit of time for the engine to fully circulate the oil at startup.  The main issue is that the very high tolerance of a modern motor needs a much finer film of oil between the moving parts.  Synthetic oils lend themselves much better to working at much lower viscosity needed at these tolerances.

Motor Oil Grades

When buying motor oil, the people at the auto shop would most likely asks you if you want single grade or multi-grade oil. Or perhaps would asks you for the viscosity rating of the oil your using. You might have come across terms like 40W, 10W-30 etc. and wonder what do they mean.

Motor Oil is divided into 2 main grades as established by the Society of Automotive Engineers(SAE). Motor Oil Grade is a numerical coding system devised by the SAE to rate motor oils according to their viscosity and flow characteristics. Viscosity refers to the oil’s thickness and ability to flow at certain temperatures.

Single Grade Oil

Usually referred to as “straight-weight” oil. This is an engine oil that does not have an additive. There are 11 viscosity grades as defined by the SAE J300; 0W, 5w, 10W, 15W, 10W, 25W, 20, 30, 40, 50 and 60. The ones designated with the W are considered Winter-grades. For example, SAE 30 is a single grade standard. This means that the oil has met the standards outlined by the SAE under testing and has come up to that rating of viscosity. The testing laboratory has made use of a standardised tube-like device and timed the flow of the oil at a given temperature. The number 30 represents the time, in seconds, for the oil to flow from one end of the tube to the other end.  That means quite a bit to your engine.  It will determine how easy/hard it is to pump around. It will also affect how well it flows around the metal bearing etc.  Later model motors with very high engineering tolerances (Small gaps between surfaces) generally need a lower viscosity oil.

Multi-Grade Oil

This is a single-grade oil with polymer additives combined with the base oil. The additive makes this oil better suited to be used all year as it allows the oil to maintain the viscosity properties of the base grade oil at low temperatures at startup, while maintaining the viscosity of the oil when operating at high temperatures. An example of this is 5W-30. The 5W refers to the viscosity of the oil when it is operating in cold weather like during winter. The 30 is the viscosity of the engine at operating temperatures.

So why is it important to be aware of the grades of motor oil? The answer is simple. Knowing a little about the various grades of oil, will allow you to easily identify oils that suit your vehicle specifications. Choosing the wrong specification of oil can cause many hidden problems inside your engine and affect the life of the engine.  Remember that many mechanics use ‘bulk’ 44 gallon drums of oil.  That means that they have picked a ‘mid’ point and have decided that its ‘good enough’ for the average punter.  If you don’t ask about your oil, often you won’t get the oil that is correct for your vehicle. You can of course find the correct specification of oil in your handbook.  You can also check it at most auto shops.  They will have a book with most cars listed in the oil section.  Or alternatively ask at a dealership that sells your type of vehicle they will likely be happy to help.  There can be cases where you could be advised to use a different oil to the ‘normal’ oil that goes with your vehicle.

Some of the factors that are important to consider when choosing oils are as follows:

  1. Weather conditions.

    Are you driving in extremely hot or cold environment? Or both?
    For cars that use Multi-Grade oils, the number with the W becomes significant especially on those months when the temperature is low. The lower the number, the “thinner” the oil is and the better it will be on lubricating the engine as it will flow faster to the parts of the engine. It may even result in faster engine start-up during cold seasons. This might not be true, however, if you are in a very hot environment. We do know that the longer the engine runs, the more it heats up and oxidation occurs. Oxidation happens when oil is subjected to high temperatures. So if the car is operating in a very high temperature environment it may be that the oil becomes thinner and performs like a much lower viscosity oil that it tested at. Only accept expert advice if you think there is a problem with the environment you drive in.  Modern Multi-Grade oils are pretty good at handling a wide set of variations in the environment.  Get the manufacturer of your car’s advice here.

  2. Age of the Engine.

    As the engine ages, more wear and tear accumulates. The bearing clearances also increases due to the age of the engine. Hence there is a need to switch to thicker oil to properly maintain correct oil pressure. Of course if you are noticing a lowering of oil pressure you should immediately get your engine checked out.  If for example the engine oil light comes on, this can be an indication of a serious problem.  You should as quickly and safely as possible pull over and check your oil levels.  If there is a problem with the level, it is best not to drive the car until it is topped up.  You should take the vehicle to a service centre as soon as possible.  Seek advice from a skilled mechanic before you consider changing oil from the manufacturers recommended specifications.

  3. Type,Size of the vehicle/Workload

    Do you have an SUV in off-road conditions? Do you demand more work from your car or vehicle than an average commuter? These factors need to be considered. The reason is that you may be putting your engine under much greater load than the average person.  The quality of oil you use may need to be a lot better than average.  High quality synthetic oils that handle great load and extreme temperatures with a wide tolerance are expensive.  But may well be worth it in your case.  Once again it is very impotent to use a suitable oil.

  4. Engine Type: Diesel or Gasoline?

    Diesel engines need particular care. Diesel engines have been known to contaminate the oil with carbon particulates over time.  These small pieces of carbon can do a lot of damage if they are allowed to build up inside the motor.  Diesel oil has special additives that help keep the diesel engine clean and free of these contaminants.  There can also be a risk of oil in a diesel engine becoming thinner with use. The thinner the oil becomes, the faster it can bypass the valves and rings and can be burnt up which would result to less amount of oil to lubricate the parts of the engine. For diesel engines, it is critical to use only diesel oils that are rated and specified by the OEM(Original Equipment Manufacturer).  Never be tempted to use standard petrol engine oil in your diesel motor.

Recycled Motor Oil

Motor Oil is comprised of about 80% virgin base oils and 20% additives. These additives include dispersants and detergents. The main purpose of these additives is to keep contaminants like sludge, carbon and residue in a state of suspension as well as to clean the engine areas where these contaminants could form.

Over time, these additives wear-out making motor oil less effective in doing its functions which is to protect the engine from wear and tear, lubricate the engine’s moving parts to prevent friction and minimise heat, etc. However the base oil molecules are still intact and can be re-refined.  When this happens, an oil change is needed.  When to change the oil in your car is usually defined by your car maker.  An oil change is needed to keep the optimal performance of your car’s engine.

As you could imagine, all this engine oil changing, means there is a lot of old oil accumulating at mechanical workshops and in home garages etc. If used oil is not properly disposed of it is very harmful to the environment. Used oil, dumped into storm drains or regular trash can contaminate bodies of water that could result in damage to marine life and pollution of our drinking water sources. If old oil gets spilled on the ground, it can also render land un-useable for agriculture for quite a while.

One of the best way to minimise, if not totally eradicate, the dire effects of used motor oil to the environment is to recycle it.

Types of Recycling

Generally, used oil can be recycled in several ways. It can be used to:

  1. Make Lubrication Oils for Vehicles – used oil undergoes processes to remove water and other contaminants at the oil re-refineries.  Using advanced and newer techniques of re-refining, the resulting product is a base oil of high quality comparable to base oils made from crude oil. Examples of these new techniques are Flash Distillation and Hydro-treating. Flash Distillation is used to remove water, fuel and other contaminants found in the used motor oil. Hydro-treating on the other hand is used to refresh the molecules of oil and reduce nitrogen and sulfur. Recycling motor oil this way is a great outcome because it can theoretically prolong the life of the oil almost indefinitely.
  2. Supply a Fuel for Industrial Operations – this is a less preferred method. In this process, used oil is filtered to remove water and contaminants. It is then burned to produce heat and/or to power machinery in industry.  Of course, once oil is burned, it could no longer be recovered. Burning oil also adds up to the pollution of the environment as the burning process release harmful elements like zinc, carbon monoxide and carbon particulates.
  3. Make Diesel Engine Fuel – this is possible but we are not aware that it is being done at scale at the writing of this post. In recent times, is has also been shown to be possible to make used oil into petrol or gasoline type engine fuels. These processes at this stage are pretty inefficient and costly.

Benefits of Recycling Used Oil

  1. Environmental Benefits – The primary reason we need to recycle used oil is to prevent further damage of our already pollution-battered environment. Poor disposal of old oil by individuals and companies has and is still a significant cause of pollution. Putting the used oil in the hands of professional recyclers and re-using it, can make a big difference. Of course it is important to also note that human health can also be protected from the risks of used oil contamination of our land/water.
  2. Conservation of Natural Resources and Reduction of Green House Gases – Motor Oil can be recycled and re-used; this helps preserve crude oils. It is interesting to note that it takes around 1 gallon (approx. 3.7 litres) of used oil to create around 2.5 quarts (approx. 2.3 litres) of engine oil compared to about 42 gallons of crude oil needed to the same 2.5 quarts.
  3. Economic Benefits – Interestingly, it may at this stage not be technically cheaper to make recycled oil then produce it as a byproduct of crude. This is for a range of reasons. Some of the main reasons are that many byproducts are being produced at the same time as crude oil is being refined. This means that the cost of refining is amortised over all the products produced. The production is also done at a very large scale and has been perfected over many years. It will probably take a different accounting method to show the real benefit here. Often, very little ‘real’ financial value is placed on points 1 and 2. But almost counter-intuitively, it is generally much cheaper to put recycled oil in your car. This may be due to a lot of reasons, such as middle man costs or branding and marketing costs of putting non recycled oils on the shelf. However, it will be interesting to see the benefits we will get, if and when the use of recycled motor oil to create lubricants or even engine fuels go full scale. One important economic benefit is the future cost of cleanup of dumped oil in landfill and of course by accidental contamination of waterways. The cost of these cleanups can be significant. Effective oil recycling procedures and laws can directly reduced this environmental cost.

Additional Information About Recycled Motor Oil

  1. Recycled Motor Oil Is Not Filtered – Recycled Motor Oils undergo almost the same process and techniques as normal crude oil to create high quality base oils.  Additives are then combined, just like standard motor oil, to increase its effectiveness in keeping the engine at its optimum performance.
  2. It Is Not Inferior To Standard Motor Oil – Used Motor Oil is unlike any other used products that tend to degrade because of use and introduction of contaminants like dirt or water. As mentioned earlier, the additives in the Motor Oil are the ones that get degraded and not the base oil itself. The base oil is extracted from the re-refining processes done in the factories.  Once that is done, additives are then introduced to the finished product.

What To Look For When Buying Recycled Engine Oil

Make sure to check the rating of the oil compared to vehicle specifications. The oil must still meet the viscosity and grade ratings of your vehicle.  If the engine oil for your car is meant to be 20W 40, then the oil must meet that rating.  If your oil must be synthetic oil, then choosing recycled oil may not be a good decision and cause damage to your engine.  Likewise, recycled oil may not be suitable for diesel or performance engines.   So please check carefully. If recycled motor oil is suitable for your car, then go for it.


Tyres, are an often forgotten part of the car.  For a range of reasons they require the utmost care and maintenance. The reason being is simple. Tyres provide the contact between your car and the road you travel. As the kilometres/miles tick away, they wear and may be damaged. The performance of the tyre will degrade as it wears or becomes damaged.  The wear and damage can be magnified if they are not properly taken care of.

Neglecting proper care of the tyres; like for example not checking the correct pressure, can lead to many tyre related issues.

Common Tyre Problems

  1.  Under-Inflated Tyres

    When a tyre is under inflated it wears out faster; creates excessive heat in the rubber and air inside it. It also makes the vehicle much harder to handle, especially under braking or hard cornering. The car may feel to be travelling ok in normal driving, but in a situation where the driver must react quickly the loss of control caused by under inflated tyres can be catastrophic. If you have ever had this happen to you, you will likely be more attentive. I painfully remember having a tyre that was under inflated on one side and thinking I will get away with it for a bit longer. Only to lose control of the car going to work on a country road down a mildly steep hill that had a high speed bend. To my horror with me furiously working the wheel to try to save my life and avoid hitting anything, the car did a full 360 degree spin at around 100km an hour. The tyre had rolled on the rim under load causing the front end of the car to throw itself wildly toward the embankment. I managed to keep the car from going off the road, but used both lanes to spin myself to a stop, if there had been someone coming the other way, I don’t know what would have happened. I would have had to make a snap decision and probably hit the embankment at very high speed… It was a pure fluke that something far worse did not happen. As is was, it was 10 minutes before I could stop my knees shaking, I knew I was lucky to be alive. I changed the wheel and got to a tyre shop and got all the tyres replaced that morning. I now pay much more attention to everything about my tyres.

    Another thing to consider, is that when driving a car with under inflated tyres, your fuel consumption can increase as the car’s engine need to exert more work to compensate for the increase in rolling friction. With the cost of fuel as high as it has become, dollars saved by keeping the tyres within pressure tolerance can be a real benefit. Not to mention the added cost of buying new tyres early. With some tyres under inflation can cut the life of the tyre to half or worse. High performance or wide profile tyres particularly, can wear very quickly when under inflated. Scrubbing of the tyre at the edges can be much worse on the front tyres due to the added forces of cornering and braking load placed on the front wheels. Lets say a pair of tyres cost you $200 for the front of your vehicle. That means that you can easily blow $100 worth of rubber life, with a pair of tyres that should have lasted 50,000 kilometres only lasting 25,000. You can generally find the pressure rating for the tyre on the tyre wall. You should not vary from this specification unless you really know what you are doing. If the tyre loses even a few pounds of pressure you should get it sorted out. If the tyre is needing to be regularly filled. Then you likely have a slow leak. You need to go to a tyre service station and get it fixed. Do not put it off. Putting off a leaky tyre repair can be a life and death decision. It is important to note that with a modern low profile tyre there is very little margin for error. The volume of air that is in a modern low profile tyre can be much less than the old style of tyre. Therefore a small leak can result in a tyre that is under inflated very quickly.

    Under-Inflated Tyre
    Wear Caused By Under-Inflating A Tyre
  2.  Over-Inflated Tyres

    Over inflation can cause faster wear and tear and could lead to a blow out. A blow out is where the tyre actually fails and blows off the rim. Once again this is a life threatening situation. The modern car tyre is a lot less prone to this sort of issue, but will still fail if badly treated or worked outside its specification limits. It is worth remembering that in hot driving conditions over inflation will be made worse. The hot air in side the tyre will increase the pressure even more. It can lead to an accident that could mean damage to the car and a considerable amount of money for repairs or worst the lost of life. Similar to under inflation, over inflation will increase wear. The likelihood of wear in the middle of the tyre goes up. The over inflation can cause the profile of the tyre to become rounded rather than flat. Causing firmer contact in the middle than the outside edges of the tyre. Once again this is more pronounced with low profile wide tyres on many modern vehicles. It is worth remembering that the modern low profile tyre has a lot less air by volume in it than the old type of high wall tyres. It is very easy to over inflate them, due to the small amount of air needed to fill them.

    Over-Inflated Tyre
    Wear Due To Over-Inflating A Tyre

Below are some tyre tips that could prevent or help minimise problems from occurring on tyres.

  1. Rotate the Tyres to even out wear. This simply means to change the position of the tyres to ensure all tyres wear evenly and lasts longer. Ask the tyre shop that fits your tyres when you should come back for a rotation with your type of tyres and vehicle. Make sure the right pressure are on the tyres after rotation. This will help you make sure that you get the most out every tyre. Even the best maintained vehicle will still wear tyres more on say the front than the back. This is due to the load that is placed on various parts of the car under braking and cornering.
  2. Check the tyre pressure regularly to make sure they are properly inflated. This can become part of your routine every few fills at the petrol station. If you identify one tyre is losing more air than the others, then get it checked for leaks. I have found over the years that as tyres get closer to the end of their wear cycle, you need to check them more often. They always seem much more prone to leaks as they get close to replacement.
  3. Replace Valve stem covers. These are not expensive yet they play a vital role in keeping dust out of the valve stem which could cause problems.
  4. Check the car’s alignment. Out of alignment suspension systems can cause uneven wear on tyres that could result to handling problems. Potholes and rough roads can quickly create an alignment problem. If you suspect you may have an alignment problem, make sure to get it fixed. Once again you can end up cutting the life of your tyres to nothing in just a few kilometres/miles.
  5. Where it is safe to do so, avoid debris on the roadway and drive as smoothly as possible.
  6. Avoid spinning the tyres, hard stops and turns wherever possible. Always follow speed limits.
  7. Do not overload your vehicle. Always check the maximum load your vehicle can carry to avoid unnecessary stress to the tyres or to other parts of your vehicle.

How to Check Tyre Pressure

  • Purchase and Use a trusted pressure gauge.
  • Check the pressure when the tyres are cold. Ideally in the morning when you have not driven yet. The reason is that when the car has already been driven, the air inside the tyre expands due to the heat generated and will give you an inaccurate reading of the pressure. If you have been driving, remember there may be a slight increase in pressure if the tyres are very hot.
  • Unscrew the valve stem cap from the valve stem on the tyre. The valve stem is the black pencil-like extension near the hubcap(2-3cm).
  • Press the air pressure gauge onto the valve stem and record the reading. Make sure though there is no hissing sound coming. If there is a hissing sound coming out the reading of the pressure may not be that accurate. To remedy this, adjust the angle of the pressure gauge until no hissing sound can be heard.
  • Compare the the reading to the rating of the tyre. (Usually printed on the tyre wall.) If it is the same, then you are good to go. If it is lower, then you need to add air until the pressure is the same. If it is above the number specified, let the air out until it matches the specified pressure.