This post was most recently updated on February 26th, 2019
By way of clarification, motor oil is also one and the same as engine oil or engine lubricant. This is, of course, different from transmission/gear oil, power steering oil or any other lubricant used in a vehicle for that matter. In today’s post, we shall critically analyse the effects of using the wrong Motor/engine oil viscosity in your vehicle. Not only that, but I will also touch the effect of overfilling your engine with oil and the dangers of engine oil shortage in your vehicle.
I will briefly talk about why our cars need engine oil. Vehicles need it in order to operate smoothly. The role of engine oil is to keep the moving parts of the engine lubricated, to protect them against rust, corrosion, and — with modern detergent oil additives — to keep them free of sludge and general engine gunk.
What is motor oil
Motor oil, engine oil, or engine lubricant is any of various substances comprising base oils enhanced with additives, particularly antiwear additive plus detergents, dispersants and, for multi-grade oils viscosity index improvers. Motor oil is used for lubrication of internal combustion engines of vehicles.
What is high-mileage motor oil
To many, the term “high-mileage oil” makes no sense. Well, we will try to explain this in this section. A High mileage oil is designed for vehicles with more than 75,000 miles. These types of specially formulated oil are more expensive than conventional ones. Such oil features additives that help protect seals. Some high-mileage oil can be synthetic while others can be a synthetic blend or base oil. As general advice, if your vehicle is high in mileage(that is 75k miles or higher) and high performance, it’s suggested that you go with this type of oil. however, Not every car requires synthetic or high mileage oil.
What are the best types of high-mileage motor oil?
I personally prefer the Castrol brand. The reason is that Castrol is the most widely available and popular. High mileage oils include additives to condition the seals to help reduce seals shrinking and allowing oil to seep through as well as other additives to help protect higher mileage motors from wear.
When you may not use a High-Mileage motor oil
If an engine isn’t burning or leaking oil, or if it uses, say, less than a quart over 6,000 miles or so, switching to high-mileage oil may not be worth the extra cost for you.
It’s really a judgment call if you should pay more for high-performance oil when your vehicle has 100,000 miles on it but is using little or no motor oil. High-mileage motor oil doesn’t hurt and it could prevent leaks from starting. Most vehicle manufacturers would say it’s normal for an engine to consume some oil between oil changes.
Best oil change practices for every car owner
Here are some oil maintenance tips that when applied, would make your vehicle’s engine last very
- Keep your oil as clean as possible always: your oil weight/viscosity must be the one recommended by the manufacturer. Just make sure you keep it changed regularly.
- Change your oil every year if that car has not to be driven: Oil deteriorates over time, as much as it is good to change your oil before storing your vehicle for an extended period of time(like a year). It is equally good to replace the oil yearly when you are not driving the vehicle.
- Use high quality recommended oil filter only
- Change your oil filter every time you do an oil change
- Don’t ever add any special oil additives to your engine
- Buy your oil from only known and trusted brands
Major Types of Motor/Engine oil
- Conventional motor oil
Conventional lubricants are made from crude oil. It’s extracted from the ground and then extensively refined to remove impurities. After that, it gets blended with other chemicals before landing on the shelf of your local auto-parts store. No matter what you do, “conventional oils have a level of insoluble – paraffin, waxes, silicon, dirt – natural contaminants.” Under certain conditions, these substances can form deposits inside an engine.
- Synthetic Blend Engine oil
Part-synthetic also called synthetic blend or semi-synthetic—oils are blends of mineral oil (conventional) and synthetic base oil. Part-synthetic motor oil is designed to have some of the benefits of a full synthetic but at a lower cost.
- What is Synthetic Motor/Engine oil?
By comparison, synthetic oils are typically manmade. Although not necessarily, are usually derived from natural gas or alcohol,” meaning they’re pure from the get-go, containing no undesirable contaminants. They are also more stable at a variety of temperatures. They don’t thin out as much when they get hot or excessively thicken in cold weather.
Using wrong Motor/engine oil as it regards mixing of synthetic oil with a conventional/regular oil
Is it safe to mix synthetic with regular oil?
For example, you put synthetic oil in your car when you got your oil changed. Then one day, You see you are running about a quart of oil low, but all you can get is regular motor oil. Is it alright to use the regular oil or will you risk harming your engine by doing so?
According to Mobil Oil, it should be fine to mix oils. Besides, it would be unlikely anything bad would happen, such as a gel-forming from an interaction of the chemicals (a common fear), because the oils are compatible with each other. Just make sure you are mixing oil of the same viscosity(E.g 5w-30 vs 5w-30). Many oils are a blend of natural and synthetic oils. So, if you are low on oil, don’t be afraid to add a quart or two of synthetic oil if you are using regular oil or even regular oil if you are using a synthetic.
The negative effects of mixing engine oil
Don’t make it a habit to routinely mix oils. This is because the additives in different products may interact or the oils may become destabilized by the mixture. You may also reduce or negate the properties of the additives. You could lose the benefits of the more expensive synthetic oil. So, adding regular oil to your special synthetic oil will mean you’ll need to get your oil changed sooner than you would have otherwise.
In order to avoid using wrong Motor/engine oil, you need the correct place to find the right oil type for your vehicle. In addition, you must predetermine if your vehicle accepts synthetic oil or not. To answer this important question, you can find the type of engine oil from the following locations.
- Your engine oil fill cap: the picture i used above is an example of a fill cap. every vehicle has one. Get only the type of oil written on this cap
- There is even more elaborate information about the type of oil required by your vehicle in your vehicle’s manual. This includes the option of synthetic oil as well as the temperature tolerance of your type of engine oil. Summarily, your car’s owner’s manual will list the recommended oil weight, whether that’s a standard like 10W-30, 5W-30, 5W-20 or something more unusual.
Which Type of Vehicles can use Synthetic oil?
This is an area I found very fascinating. In Africa, especially Nigeria, we tend to follow the bandwagon a lot. If for example, my neighbour is using Mobil high-performance conventional 20W-40 motor oil to service his 1990 Toyota Corolla sedan, without doing my own research, I may simply ask him about the type of oil what he is using and start using it on my Toyota Corolla, 2010 model.
This is a scientifically wrong practice. It goes without saying that changes are made to engine components over the years. What oil is good for Mr A may not be good for Mr B.
Moving forward, conventional/regular oil with the right viscosity or weight will be 100% compatible with both 1989 Toyota and 2010 Toyota. However, your Corolla 2010 can safely use synthetic oil while the 1989 synthetic oil might be detrimental to the engine performance of a 1989 corolla. Furthermore, you augment the extra cost of buying a synthetic oil by having a comparatively longer oil change interval.
Let’s do basic mathematics on this. For example, if you bought pure synthetic oil for like #16,000 for 5 litres, you will buy the conventional oil for like #4,500. Now, synthetic oils are designed to last way longer. if your car’s manual says you should change oil every 5000 to even 15,000 miles in some cases, it means you can use it for a year or more(maximum of a year) regardless of how often your drive before a change.
On the contrary, you will need to change your conventional oil at least every 3 months. Now, 4500 x 4(months in a year) = #18,000 (this is minus cost of labour and the cost of your oil filter, the stress and time wasted)
Determining what vehicle can use Synthetic oil
Best practice is to check the manual of your car to see if your car supports synthetic oil. From my personal research, most cars manufactured in the year 2000 and beyond, can run on synthetic. Typically, high-performance vehicles will be more likely to require synthetic oil, as will vehicles that have a turbocharged or supercharged engine. However, if your vehicle does not require synthetic oil, the choice is trickier – and there is no clear answer so please check your car’s manual. Let me quickly add that if your car’s manual does not require synthetic oil, you may still use it but it will add no extra value to your vehicle.
Consequently, if your car doesn’t require synthetic oil you should perform a cost/benefit analysis. But that can be difficult to do due to vague claims made by manufacturers. There may be no reason to spend more on synthetic oil, except for peace of mind or to save extra cash.
What is Motor/Engine oil Viscosity/Weight & its Significance?
First off, the viscosity or weight of an oil is the ratings or grade giving to it by the manufacturers in relation to how it holds up in variations in temperature. You can see the oil viscosity of your vehicle on your owners manual on clearly written on your oil fill cap under the hood. Also, note that single grade oil is different from multigrade oil. If you have SAE40 that is a single grade viscosity but if you have 5w40, we are talking about multigrade oil here.
Note: in the case of Nigeria and any country of the world where we have a hot temperature, if your car manufacturer specifies 5w20 oil for your car for example, it is safe to use y a 5w30 or 10w30 oil. I will advise you not to go further higher though.
Most of the time when the viscosity is explained words are used that are too technical for the average person to quickly grasp. This leaves them still wondering what the viscosity numbers really mean on a bottle of motor oil.
Simply put, the viscosity is the oil’s resistance to flow or, for the layman, an oil’s speed of flow as measured through a device known as a viscometer. The thicker (higher viscosity) of oil, the slower it will flow. You will see oil viscosity measurement in lube articles stated in kinematic (kv) and absolute (cSt) terms. These are translated into the easier to understand SAE viscosity numbers you see on an oil bottle.
What can a 5W-30 oil weight do that an SAE 30 won’t?
When you see a W on a viscosity rating it means that this oil viscosity has been tested at a Colder temperature. The numbers without the W are all tested at 210° F or 100° C which is considered an approximation of engine operating temperature. In other words, an SAE 30 motor oil is the same viscosity as a 10w-30 or 5W-30 at 210° (100° C).
The major difference is when the viscosity is tested at a much colder temperature. For example, a 5W-30 motor oil performs like an SAE 5 motor oil would perform at the cold temperature specified, but still, has the SAE 30 viscosity at 210° F (100° C) which is engine operating temperature. This allows the engine to get a quick oil flow when it is started cold. The advantages of a low W viscosity number is obvious. The quicker the oil flows when the engine is cold, the lesser it experiences dry running. Less dry running means much less engine wear.
Using wrong Motor/engine oil Viscosity in your Vehicle
To start with, when you use engine oil with too high of a cold viscosity rating in cold weather your car will not start.
Similarly, If you use an oil with too low of a hot viscosity/weight rating the oil can shear and lose film strength or thin out at high temperatures. This can by extension lead to improper lubrication and the burning of oil.
Thick vs. thin oil is a film strength vs. flow rate tradeoff. Thinner oil means the oil film is more likely to be “squeezed out”, and thick oil means less will get there in the first place
So the main concerns with oil weight are how much damage is caused by the oil being too thick when cold (it is said that most of the engine’s wear happens when the engine is cold, and a thinner oil will flow better at cold temperatures). And how much damage is caused by oil being too thin when it is hot(This is the reason why i said a 0w20, 5w20 oil may be too thin for hot temperature.
Ideally, choose an oil with the lowest cold rating possible with the narrowest span of viscosity for the expected temperatures. And it never hurts to use the manufacturer’s recommended viscosity.
Can I go Back and Forth Between Synthetic & Regular oil?
Yes, you can go back and forth between conventional and synthetic oils without damaging the engine. This is particularly true considering many synthetics have conventional oil in them already. Use true synthetic oils for maximum performance.
The Advantages of Synthetic oil Over Conventional oil
- One major benefit of synthetic oil is molecular consistency. Being an impure substance, conventional lubricants are made up of molecules that are of different lengths. there are small, medium and long hydrocarbon chains. Synthetic oil is comprised of only medium-length molecules.
The problem with conventional oil is that those short, lightweight hydrocarbons tend to burn off when they get hot. This causes the oil to thicken the longer it’s in an engine which ultimately results in frequent change.
- Another advantage is that synthetic oils also handle high temperatures better than conventional lubricants. They’re better at transferring heat, meaning synthetic oils can actually help a vehicle’s engine run cooler
- A Longer draining interval as a result of being more resistant to breakdown or “shearing”. Synthetics are much more robust than conventional lubricants, something that can really pay off. The drain interval can safely be extended anywhere from 10,000 to 12,000 miles, or three to four times normal oil, while the added cost of synthetic is nowhere close to that.
- Synthetic oil offers better fuel economy: Yet another way synthetic oil can save drivers money is through improved fuel economy. Don’t go looking for a huge increase if you make the switch, but it can actually boost efficiency by around 2 to 3 percent, a modest but welcome improvement. Ford has also started to use variable-displacement oil pumps, which move less oil at lower engine speeds to help boost efficiency even further. With these improvements, Ford has started advocating 10,000-mile change intervals on its vehicles, helping lower maintenance costs for customers.
Best Synthetic oil for Individual Vehicle Models
On a general note, you can buy your oil from any reputable seller. If you use a German vehicle like the Mercedes Benz, Audi, Opel, BMW, Volkswagen the manufacturers recommend please “Liqui Moly” motor oil. This doesn’t mean you cannot use liqui moly on other vehicles, just that it performs best in German cars.
Other synthetic motor oils that are very popular and great are:
- royal purple,
- Castrol edge (now becoming popular in Nigeria)
- , Mobil 1(from our dear Mobil oil company. extremely popular in Nigeria)
- liqui moly(superior oil for german machines. also becoming popular in Nigeria
- shell Rotella,
- Total oil(their best synthetic oil is scare in many cities in Nigeria unlike mobil)
- Oando(has synthetic oil for average cars but has a very good conventional oil)
Dangers Associated with Engine oil Overfill & Underfill
I won’t dwell much on the consequences of oil underfill, this is because we know that when your oil is extremely low, it causes imminent or fast damage to your engine. What happens when you put too much oil n your engine?
Effects of too much Engine oil in your Vehicle’s Engine
- if you really overfill (not just by a cm or so) then internal crankcase pressure can force lube oil along the valve stems and into the cylinders. At which time the engine is not under control of the diesel fuel injection pump, and can “run away” with masses, of white smoke. In other words, you cannot stop your vehicle normally the only way to stop your car in such a situation may be to jam the vehicle into gear and stall it on the clutch.
- Whenever you detect an overfill(the normal gauge is when the oil is in between the upper and lower mark of the dip stick, I don’t think a small overfill will hurt, but to be safe use an extractor, and get the level down to normal.
- The level of damage depends on the amount of overfill. Consequences are identified by a smoky engine with lots of smoke from the exhaust.
- Also, an oil overfill can cause damage to the oil seals.
- Oil spillage over the engine and compartment.
- Bent connecting rods or broken rods that would end up smashing the engine block.
We cannot overemphasize the correct use of motor/engine oils. using wrong Motor/engine oil weights come with dire consequences. We have also learnt that underfill and overfill of oil into the engine are very bad for your engine. Finally, we have learnt one or two things about determining if your car can use synthetic oil or not. See you in the next article.