Why You Should Always Use The Correct Motor Oil In Your Car

Richard Green
August 17, 2006

Motor oil, coolant, clutch, transmission, power steering, and brake fluids are all vital parts of all cars. They need to be regularly checked, topped up or changed whenever required to ensure that the vehicle operates properly. The car owner's manual will show what the manufacturer believes to be the best regular maintenance schedule for the particular model. Making sure that the advised service intervals are maintained may sometimes seem like an unnecessary expense, but it will help protect the car, preserve efficiency, increase the vehicles lifespan and reduce the risk of future unexpected bills.

Taking the correct care of a vehicle will not only help to ensure that it will run correctly and efficiently, but will also help to make sure that it is running safely. It is also important to note that many vehicles' warranties will become invalid if the manufacturer's service requirements are not scrupulously followed.

The engine oil that is made for use in cars ensures that all the moving parts of an engine are properly lubricated and protects them against the wear and tear caused by the friction of everyday operation. Additives which are put into the base oil also provide additional engine protection, helping to prevent the car engine oil from deteriorating under the engine's extreme operating temperature conditions.

Like all fluids, motor oil will thin out when it is subjected to increased temperatures, and thicken when cooled. In order for the motor oil to properly protect the engine, the oil must be able to remain at the correct viscosity level at all engine operating temperatures. If the viscosity becomes too thin then the oil will lose the strength to protect the engine, if it is too thick then the oil may not pump to the proper parts of the engine, and damage may be caused as the engine revs.

Multigrade car engine oils use a base oil (usually 5W, 10W or 20W) which maintains the correct viscosity at low temperatures, along with polymers which keep viscosity levels acceptable at higher temperatures. These levels are indicated by SAE grades. When choosing appropriate engine oil, refer to the manufacturer guides and always use a multi grade that has the narrowest span of viscosity possible which is appropriate for the temperatures the vehicle will encounter. This is because the wider viscosity range oils can be slightly more prone towards breaking down due to the high polymer content.

As well as checking every couple of weeks that the engine has the appropriate levels of the correct type of motor oil, it is also important to frequently check the transmission and power steering fluid dipsticks to preserve the proper working fluid levels, and make certain the brake fluid and coolant are filled to the top. If a car is leaking fluids, it can mean serious trouble. Keep an eye on the condition of any parking spaces which are regularly used, looking for stains or spots that can warn of possible leaks.

For legal, mechanical and safety reasons always use the correct fluids and never cut corners. Do not follow the lead of David Wyn Williams from Wales who the BBC reported was recently arrested for using cooking oil instead of brake fluid.

The prosecutor, Sarah Lambert, said that although the brake fluid reservoir was full, the liquid inside was a strange colour and had congealed into "a globular, jelly-like substance." Miss Lambert went on to say that Mr Williams had pumped the foot brake 10 times but with, "no effect whatsoever". He had relied on the handbrake and the gears to slow the car instead.

The judge ordered the “death-trap” car to be confiscated, saying, "You are very lucky not to be here on a far more serious charge. You posed a very serious risk to yourself, your passengers and to other road users."

The defence lawyer in the case said that his client would be getting the bus in future.