Each manufacturer has a specific recommendation or minimum requirement for the type of oil a given engine will use. You may be wondering, what is the difference between different weights, grades, and viscosities? What is the difference between 5W-30 Y 10W-30? What do all these numbers mean? Can’t you use oil in your car or does it really matter?

Cracking the Petroleum Code

The terms weight, grade, or viscosity are commonly used interchangeably and basically mean the same thing. They refer to the thickness or ease with which the oil flows. Using a multigrade 5W-30 oil as an example, this type is widely used in millions of vehicles. The first number followed by “W” indicates the viscosity (or thickness) for cold weather temperatures. The “W” means winter. The lower this first number, the less viscous or thinner your oil will be at lower temperatures. Although it may seem trivial, the number is of great importance.

When engines first roar after the ignition key is turned, the oil pump tries to push oil from the oil pan at the bottom to the top of the engine, to lubricate all moving parts (such as pistons, camshaft, etc.) ) Cold starts are the moment of greatest wear imposed on the engine. The thicker (or thicker) the oil, the harder the oil pump will work and the longer it will take for the engine to receive the crucial oil lubrication it needs to prevent metal-on-metal friction when starting. So you have 5W- the oil will flow faster and easier than a heavier oil which would have a higher number like 10W- Prayed 15W- Petroleum.

The second number found after “W” specifies the viscosity at high temperatures. The higher the number, the thicker the oil will be at the optimum temperature. In older cars, it was common to switch to different weights of oils depending on the season. It is a practice that is not as common today due to manufacturers building lighter engines and using different engine materials than in the past, it is always recommended to follow the manufacturer’s fluid specifications found in your vehicle’s manual. different than recommended will likely result in lower fuel economy or increased engine wear

Are there exceptions to the rule?

The occasional exception to the “follow manufacturer’s recommendations” rule comes into play when an engine has aged and when moving parts may have larger gaps between components. Thicker oils can sometimes improve performance and protection in such conditions, but for most vehicle owners, follow the specifications in the vehicle manual.

What do the manufacturers say?

Some manufacturers will list a range of different types of motor oil depending on the climate in which the vehicle will be used. A lighter oil may be recommended for vehicles in arid southern areas, such as Scottsdale, Arizona, while a lighter oil may be better in colder climates, such as those found in Rapid City, South Dakota. Oil in South Dakota will obviously be subject to colder engine start-up conditions during the winter months than oil in Arizona during the same time period.

What is straight oil versus multi-viscosity oil?

You should never use pure oil (SAE30, SAE40, SAE50, etc.) in a system designed for a multi-viscosity oil. Straight oils are used for smaller engines or older car engines made before multi-viscosity oils were created. Although snowmobiles, ATVs, and motorcycles have smaller engines than most passenger cars and trucks, straight oils should not be used in such vehicles. Even regular automotive oils may not be appropriate due to specific engine designs, such as two-stroke versus four-stroke engines.

Take care of the engine you depend on

All things considered, using the proper grade of oil and changing your vehicle’s oil at regularly prescribed intervals are two of the most important preventative maintenance tasks you can perform on your vehicle. Failure to do so can lead to oil depletion and ultimately cause the engine to seize. Most repairs related to improper or careless oil handling are preventable and costly. It’s better to invest in good automotive service practices now than pay a painful repair bill later. Knowing the correct oil to put in your vehicle (and why) is a good first step in caring for the engine you depend on.