Every industry has its own lingo. The automobile industry is no different. Consumers, particularly female consumers, are often at a disadvantage when purchasing cars or having cars serviced, because they don’t understand or speak the lingo.
The following information will help bridge the gap of understanding and put you on a level playing field with car dealers and mechanics.
The first thing that you should do is read your car’s owner’s manual. This will give you general background information specific to your vehicle.
The days of traditional “tune-ups” and jiggling spark plug wires are over. Today’s automobiles are highly sophisticated pieces of machinery with many computerized parts. It’s not uncommon for a car to go 100,000 miles before it needs a tune-up or a change of transmission fluid.
When deciding on a vehicle to purchase, you may come across the terms DOHC, SOHC and OHV. These refer to the valvetrain layout of an engine, such as camshafts, valves, cam followers, etc. Valvetrain components control the air/fuel mixture that enters the engine and how efficiently the exhaust gases leave.
Overhead cams (OHV) are popular on most V8 and many V6 engines. The OHV engines have a camshaft located in the cylinder block rather than the cylinder head. There are a lot of moving parts involved and it is a fairly easy engine to build and repair. In vehicles that have a single overhead camshaft (SOHC) design, the valvetrain is simplified by relocating a single camshaft above each cylinder head.
For any “V” engine, two camshafts are required. The simplified layout (pushrods and rocker arms removed) enables the engine to carry as many as four valves per cylinder-two intake and two exhaust. This generally translates into more power. Many SOHC engines have only two valves per cylinder.
The double overhead cam (DOHC) design has two camshafts located over each cylinder head, indicating the engine has four valves per cylinder (two intake, two exhaust), for maximum power. This valvetrain has a separate camshaft for the exhaust and intake valves. In a typical “V” layout, an engine will have four camshafts. Four-and-six-cylinder DOHC engines are the most common engines built today.
Two other common terms you might encounter are understeer and oversteer. When a vehicle “oversteers,” its back wheels lose traction. This causes the rear end to slide away from the centerline of the vehicle’s travel. In “understeer,” the vehicle’s front wheels break traction and skid away from the centerline.
If you turn the steering wheel to go around a corner but the vehicle continues in a straight line, you are experiencing “understeer.” Sometimes referred to as “plowing,” understeer causes the tires to plow the road rather than roll with the road. Cars with front-wheel-drive are more prone to understeer than cars with rear-wheel-drive.
If when you turn a corner, the car’s rear end feels loose or breaks free, you are experiencing oversteer. Depending on the degree of oversteer, you can still maintain control because the front turning wheels have not broken free, or lost traction.
Many, if not most cars today are equipped with antilock braking systems, traction control and/or electronic stability control. All three systems are components of the manufacturer’s safety equipment required in today’s vehicles. A stability enhancement system helps improve traction, maneuverability and stability in all weather conditions. It assists the driver during braking, accelerating and cornering.
Antilock braking systems (ABS) regulate the brakes to help prevent wheel lock-up and skidding. Through traction control, the brakes are applied at drive wheels and engine power is reduced. This helps to reduce wheel spin during acceleration and works across a full range of speeds.
Electronic stability control systems apply the brakes to individual wheels and controls engine power to help correct oversteer and understeer. Drivers are better able to maintain control, especially when cornering and turning. ESP- electronic stability program – is operated by a button that allows the driver to switch off the traction control and stability control functions. You cannot turn off ABS.