oil changes

Four Things You Should Know About Oil Changes

Regularly replacing the oil in your car’s engine is still the best way to extend the life of your engine, but the problem with this is the fact that it is easy for unscrupulous mechanics, repair shops, and “quick lube” establishments to turn this common-sense preventative maintenance chore into a scare tactic.
To help you avoid falling victim to such scare tactics, we have listed four things you should know about oil, and oil changes that will not only help you identify snake oil salesmen, but save you some money as well.

Most oil is replaced too soon – Oil changes

A common scare tactic used by less than honest mechanics is to say that your oil needs changing because it’s black in color, “…and if you don’t, you could lose your engine.”
The fact is that with the exception of new engines, the new oil in an engine turns black almost immediately. This is caused by the old oil that remains in the engine; this oil mixes with the new oil, turning it black. This does not affect the new oil negatively, and with the new oil, you should be fine for the expected life of the type, grade, and quality of the new oil.
These days, there are no car (or oil) manufacturers that recommend replacing oil every 3 000 miles (4 800 Km), despite claims to the contrary by many mechanics and quick-lube joints. Of course, there is no harm in changing your oil twice as frequently as you should, but why change it when the manufacturer recommends replacing it at 6 000 miles (9 600 Km)?
By sticking to the oil changes intervals stated in your maintenance schedule, you not only protect your engine- you save a lot of money over the useful life of your car as well.

Don’t use dual -purpose oil.

To maximize their profits, many repair shops and quick-lube joints use dual-purpose oil. This type of oil is “designed” to be used in both gasoline and diesel engines, but despite claims by their makers, these oils do NOT offer the best of both all possible worlds in terms of engine cleaning and lubricity.
The fact is that conditions inside a diesel engine are vastly different from those that obtain in gasoline engines. Diesel engines produce different types of combustion products (and more of it), than are produced by gasoline engines. Therefore, to keep a diesel engine clean and lubricated, specially-designed additive packages are required.
Additive packages in oil can account for up to 25% of the oil’s total volume, and this is fine if the additive package is designed for a specific purpose, say, for use in a gasoline engine. So, if you want to formulate an oil that is suitable for both diesel and gasoline engines, you need to add more additives to deal with diesel combustion products, which can elevate the total additive content of the oil to 35% and more.
What this means in practice, is that the base oil content is only about 65%, with the rest made up of additives that could (and often do) interfere with the lubrication of highly engineered gasoline engines.
The safest thing to do is to stick with the oil recommended by the manufacturer of your car. If they do not recommend dual-purpose oil, don’t allow a mechanic to talk you into using it.

Use the correct type of synthetic oil – Oil changes

More and more car manufacturers are designing their engines to take advantage of the increased lubricity of fully synthetic oils. The main advantage of synthetic oil is that since they are distilled from various hydrocarbon-rich gases, the resulting molecules are all exactly the same size, which is not the case with refined crude oil.
The uniform size of synthetic oil molecules allow for smaller engineering tolerances in engines, as well as the use of new-generation steels that have a natural affinity for synthetic oil molecules. This means that the steel “attracts” a protective film of oil which clings to wear surfaces, even if the engine is not working. This provides almost perfect lubrication during cold starts, which goes a long way toward eliminating mechanical wear.
However, even fully synthetic oils require the addition of additives like friction modifiers and detergents, and herein lies a potential problem. European car makers are allowed to develop specific oil formulations for use in their products, which is something American car makers do not do. The only standards American oils have to comply with have to do with the Clean Air Act, and they don’t have to make provision for special lubrication requirements.
One example of special lubrication requirements is the fuel injection system in some new Volkswagen diesel engines. These systems use pressure pumps that are driven directly by the engine, and using incorrectly formulated synthetic oil can destroy the pump.
If you drive an imported European car, make sure that the synthetic oil you get during a routine oil changes is formulated for the specific needs of your engine. Make sure that the European oil standards, as opposed to only the SAE (Society of Automotive Engineers) standards are displayed on the container, and that the formulation conforms to the requirements of your engine.

Don’t use mineral oil if you need synthetic oil – Oil changes

Substituting mineral oil for synthetic oil is a foolish economy. Engines that are designed for synthetic oil are also fitted with emission control systems that are designed to cope with synthetic oil. Apart from the fact that mineral oil cannot lubricate an engine that is designed to be lubricated with synthetic oil, the fact is that mineral oil can, and does, damage catalytic converters, oxygen sensors, and other emission control components.
There is simply no way to repair a catalytic converter that has been damaged by mineral oil. The only remedy is replacement of the catalytic converter, along with all the other damaged emission control components. The total cost of such a repair will make the money you “saved” by using mineral oil look like a tiny drop in a vast ocean, so do yourself a favor and use the correct oil- every time.