Engine oil myths that could cost you money.

Some of these engine oil myths have been around so long that they’ve become urban legends.

How many times have you heard someone slating an oil as “inferior” because it discolours? Well although the theory is sound in certain cases, this is an engine oil myth.

A little knowledge isn't necessarily a dangerous thing, but a little knowledge that doesn't happen to be true could quite possibly ruin your engine, or at least cost you a lot of unnecessary expense.

Here are the 10 engine oil myths that have become urban legends.

Engine oil myth No1: Oil must be changed every 5,000km’s

Many years ago, most auto manufacturer recommended motor oil in be changed every
5,000 km. Using oil past that interval and you ran the risk of sludge buildup, which would not only degrade performance but leave the moving parts at risk for damage.

That's no longer true. Modern detergent oils, improved oil viscosities and better auto engineering in general have extended engine oil changes to 15,000km’s (Further with a good synthetic, such as Habot Synthetic engine oil). Unless you drive your car under unusually demanding conditions, such as stop-and-go traffic, going 15,000km’s between oil changes shouldn't damage the engine in any way.

Engine oil myth No2: More engine lube is better.

Overfilling the crankcase with oil is bad. It can cause excessive heat owing to the increased resistance, and thus shorten the oil’s life. In addition, a lot of oil will be splashed into the cylinders and cause excessive oil burning, increasing the combustion chamber deposits that can cause operational problems.

There is a popular belief that four litres of oil is just right for a four-cylinder car. This is not always the case. Check the car manual for the exact crankcase capacity as you may be able to save some oil for topping up. Remember to fill the crankcase to the level indicated on the dipstick – never more, never less.

Engine oil myth No 3: The "W" in 10W-30 oil stands for "weight."

When you buy engine oil, it's important to know the oil's viscosity, a property that corresponds roughly to its thickness. The less viscous the oil, the more smoothly it moves through your engine and lubricates the moving parts. The best engine oils have a viscosity that is neither so high (thick) that it will barely flow or so low (thin) that it will slip through your engine like water.

There are two ways in which oil viscosity is measured: single grade and multi-grade. SAE 30 is a typical single-grade rating. That means that an organization called the Society of Automotive Engineers (SAE) ran the oil through a standardized tube-like device and timed how long it took, in seconds, to flow from one end to the other.

Unfortunately, oil changes its viscosity with temperature and the single viscosity rating only represents the flow of oil when it's warm. However in winter the oil will flow more slowly, so a cold viscosity rating is important too. A multi-grade rating gives you both the hot and cold viscosities. For 10W-30 oil, the 30 is the same as the SAE 30 viscosity rating for warm oil, but the 10W is the viscosity rating for cold oil, according to a standardized rating system developed by the SAE for winter oil use.

And that's what the "W" stands for: "winter." "W" for "weight" is an engine oil myth.

Engine oil myth No 4: Additives boost engine oil and engine performance

Additives cannot reduce oil consumption in an old engine or restore the engine protection properties of an old oil. In fact, additives may upset the oil chemistry and create new problems.

It is safer and more economical to use quality tested and ‘packaged’ premium oils. Do not waste your money on additives.

Engine oil myth No 5: When engine oil turns dark, it's dirty and should be changed.

If you're conscientious about keeping your car in good running order, you probably worry from time to time that your oil has gotten dirty and is causing sludge to build up in the engine. So you pull the dipstick out and check the colour of the oil at the tip. Chances are, it's starting to turn dark, no longer the light amber colour that you saw on the stick when the lubricant was fresh. So now it's too dirty to use, right? It's depositing sludge in your engine and needs to be changed.

Wrong. In fact, just the opposite is true. If you're using a detergent engine oil (and most modern engine oils have detergent additives), the oil is working just the way it's supposed to, dispersing the tiny particles that can result in engine sludge and holding them in suspension in the oil itself so that they can't build up. That's why the oil appears darker, but this in no way impedes the oil from performing its normal functions of lubricating and protecting the metal surfaces inside the engine.

Of course, the oil is limited in how many of these suspended particles it can contain and will eventually need to be changed when it becomes saturated, but use the oil change interval recommended by your car's manufacturer to decide when to change the oil, not the colour of the oil on the stick.

Engine oil myth No 6: Oil never wears out.

Oil does “wear out”. The primary enemy of oil is heat. At high operating temperatures, oil begins to oxidise and thicken. Furthermore, engine oils can become laden with excessive carbon soot, water, acids, dust, metal particles and oxidised materials. These can cause plugging of oil filters and passageways or interfere with the proper action of some critical engine parts.

Engine oil myth No 7: Synthetic engine oils can cause oil leaks.

Back in the 1970s, when synthetic engine oils (those based on chemical base stocks such as polyalphaolefins) first became popular, they didn't always play well with the seals and gaskets in the car's engine. They could cause the seals to shrink in ways that petroleum-based oils did not, resulting in those messy oil leaks that would mysteriously appear in your car's parking space.

Some people still fear that synthetic oil will cause leaks and so they continue to use petroleum-based oils instead.

Modern day synthetic motor lubricants have been reformulated so that this no longer occurs.

Engine oil myth No 8: Synthetic oils are costly.

When you look at the cost per litre synthetic lubricants cost more than those derived from crude.

But when you consider that these lubes can easily double oil change intervals while enhancing engine performance and fuel efficiency, the list price pales into insignificance.

Engine oil myth No 9: All engine oils are the same.

Engine oils differ in their physical characteristics, additive technology and additive content. Different oils are formulated to meet various specifications.

The selection of a suitable engine oil will depend on the engine manufacturer’s recommendation and the type of service the oil will be subjected to. Using the right type of oil can be more economical in the long run.

Don’t let engine oil myths and urban legends cost you money: To find the right oil for your car, try Habot Synthetic Lubricants.