As the lubricant for the moving parts of your engine, oil is extremely important; it prevents excessive engine wear and tear and is vital for the continued functioning of your vehicle. And it's all wrapped up in a one quart plastic bottle.
If you've ever stepped foot into your nearest auto parts store, you’ll have noticed the vast number of motor oil containers that line the shelves. Clearly, we don't need to tell you that there are many oil types to choose from, but how do you know which one is best for your car?
The Different Grades
Each type of oil is graded by the Society of Automotive Engineers (SAE). The higher the grade number - up to 70 - the higher the viscosity. These numbers are often referred to as the weight of the oil. In addition to numbering, motor oil that meets low temperature requirements gets a "W" after the viscosity grade. Simple enough, right?
Oil types can vary a great deal between cars and the environment in which they operate, but some common weights include 5W-30, 10W-20 and 10W-30.
If you look in your owner's manual, the manufacturer will confirm the type of oil you should use for your car.
As your car ages, it will need slightly thicker oil for added lubrication. The parts of your car's engine will have worn over time, increasing friction; thicker oil will help condition seals in older cars.
An oil's thickness changes with the outside temperature as well. It will become thinner with warmer temperatures and thicken when it's cold.
Viscosity of oil is an important factor in determining which type is right for your car. Too thin, and it won't lubricate the engine parts well enough when it heats up. The climate you normally drive in is important to consider.
Thankfully, most of us can use multi-viscosity oil in our cars. This oil has passed SAE specifications for thin oils at low temperatures, as well as for thicker oils at higher temperatures. They're like the all-purpose flour for the automotive engine, and they actually flow easier at cold temperatures.
Which Type Is Best?
There are three overarching types of oil - conventional, synthetic and synthetic blend. Conventional oil is organic and limited in its capabilities when compared to the synthetic oils, which have fewer imperfections in their chemical buildup. Conventional oil is highly reactive to temperatures, which isn't true for synthetics; also, synthetics give you better engine performance, as they are more slippery.
This doesn't come cheap though, as synthetic oil can cost up to three times as much as the regular stuff; but on the bright side, you don't have to change your oil as often.
Synthetic blends - a combination of conventional and synthetic oils - are a nice compromise between the two; they're less expensive, but provide some of the performance enhancement you get from a synthetic.
When buying oil for your car, the best thing to do is follow your manufacturer's recommendations. However if you're driving an older car, you can always try thicker oil. Consult your mechanic or dealership for the final say if you’re still unsure - they'll know what's right for your vehicle.