Engines & Transmissions
Horsepower is best explained along with torque, and using the analogy of "push" and "pull". Torque is what pushes you away from the starting line. But as you get underway torque levels off and horsepower is what pulls you along at higher speeds.
Cylinders
Many people believe that more cylinders equal more power. The breakdown goes something like this:
- Four cylinders - Fuel-efficient city cars which, depending on cargo, can be zippy on highways too
- Six cylinders - Mid-range power, fuel efficiency and reliability
- V8 and up - For those who value power more than fuel efficiency
In many ways this is still a good rule of thumb, but these days, engineering advances such as turbocharging, supercharging and Direct Injection can give a car with fewer cylinders the strength to outgun its higher cylinder cousins with the advantages of improved fuel efficiency.
Valves and Litres
As for those other two measurements - number of valves and litre size - here is a very basic overview. There are two types of valves in an engine:
- To let air-fuel mixtures into the cylinders (intake) and the other to expel burnt gases (exhaust). They come in a wide variety of configurations - from two to five valves per cylinder depending on the manufacturer - but the objective in all cases is to obtain the best combination of performance and fuel efficiency in most situations.
- Litres, meanwhile, simply refers to the size, or "displacement", of the engine - the larger the engine, the greater the displacement.
Transmissions
Whether you opt for a manual or automatic transmission generally has to do with your personal preference, but you should be aware that there are certain trade-offs in making the choice. As with engines, there is no substitute for test driving vehicles with various transmissions to decide what is right for you.
Advantages of manual transmissions
- Often the standard or more economical choice when buying
- "Hands-on" control means you can respond faster to changing driving conditions and may result in greater fuel efficiency
- Usually (but not always) less expensive to repair than automatic
Advantages of automatic transmissions
- Simpler driving. You don't have to keep shifting gears and physically working the clutch and gear shift. Though automatics may not change gears as fast as you would if you were controlling them manually, once you've put the car in "Drive" all you need concentrate on is the road and where you're going.
- Some, but not all, include enhanced traction features like traction control
- May be more attractive to buyers when you decide to sell
2011 models shown
