To choose the proper type of oil for your vehicle, you need to understand the significance of the oil additives, viscosity ratings, and classification codes.
Oil additives: To help the oil keep your engine cool, clean, and corrosion-free, refiners blend in various additives, which can account for as much as 25 percent of the cost of the oil.
Viscosity ratings: Oil is rated and identified by its viscosity, which determines its ability to flow.
Two types of oil are on the market: single-viscosity oil and multi-viscosity oil. Almost every vehicle is designed to run on multi-viscosity oil. The lower the number, the thinner the oil and the more easily it flows. In 10W-40 oil, for example, the two numbers mean that it’s a multi-viscosity oil. The 10W is an index that refers to how the oil flows at low temperatures (in Winter); 40 refers to how it flows at high temperatures.
To find out which viscosity to choose for your vehicle, look in your owner’s manual for an oil viscosity chart.
Oil classification codes: The starburst symbol on an oil container label means that the oil meets the current engine protection standard and fuel economy requirements of the International Lubricant Standardization and Approval Committee (ILSAC), a joint effort of U.S. and Japanese automobile manufacturers.
Synthetic oil: Some claim that synthetic oils allow longer intervals between oil changes, result in less wear on engine parts, and operate at higher engine temperatures. The longer interval claim has yet to be proven.
A battery, like other parts of your vehicle, is subject to wear and tear and should be checked regularly. In particular, pay attention to the battery’s trouble spots, shown here. A battery that’s kept clean lasts longer than a cruddy one.
Before you work on your battery, be sure to read all the safety measures involved. Here’s a rundown:
Never work on a battery with a lit cigarette in your mouth. Batteries are filled with sulfuric acid that generates hydrogen gas. If you get acid deposits on your skin or clothes, wash them off with water immediately.
Disconnect the battery whenever you work on it, but be sure to shut the engine off first! On most modern vehicles, computers control functions of the engine, fuel and ignition systems, automatic transmissions, and other stuff. Be extremely careful not to inadvertently send a shot of unwanted voltage into one of the computers and destroy it.
Always remove the negative cable from the battery if you plan to work on wiring under the hood. This prevents you from possibly damaging electrical components or receiving a shock.
When removing and replacing both battery cables, always remove the negative cable first and replace it last. If you attempt to remove the positive clamp first and your wrench slips and touches something metal, your wrench can fuse to the part like an arc welder.
Tie the cables back while you work on the battery. Don’t allow anything made of metal to connect the terminal posts; this can damage the battery. If the cables are connected to the posts when something else interferes, you can destroy the onboard computers.