When shopping for cars, there is a lot of terms manufacturers use that you may see when reading brochures or speaking with a dealer. While you may have a basic understanding of what certain things are, you may not necessarily know what everything is or what it does. If this sounds like you, then read this article as it is a basic overview of engine terms and phrases you may see when picking out a new car.
Engine Layout:When people refer to different engines you may hear the terms inline, V (insert amount of cylinders here), rotary, or Boxer used to describe the engine layout.Inline or straight engines, aka I (insert cylinder number) are called this because all the cylinders line up vertically along the crankcase. This alignment is very common due to simplicity and smaller overall size. The Boxer engine, aka flat-#, is a design that puts cylinders in a horizontal formation that are opposite of each other.What is important to know about these is that they offer a low center of gravity and generally provide better stability and control when driving.Generally, you will see a Boxer engine used with most Subaru vehicles. The V engines (such as a V6) are becoming more common as smaller engines are required to produce similar power to their larger predecessors, such as the V8. The V6 has made the inline configuration less popular as the V6 is easier to fit into most engine bays when the cylinders are put into two slanted opposing banks in the V configuration. The V6 also works well with the front wheel drive layouts that most modern cars possess. The V6 engine is the second most common configuration behind the I4 engine. The last engine type is rotary engine and generally you won't see this engine type used often as it has become nearly obsolete in newer vehicles. In a rotary engine, chambers form a circle around a center piece (the rotor) which rotates around a crankshaft. This is why it got the name rotary engine, as rotor rotates around the crankshaft. The only modern car you will see this in today is the Mazda RX-8.
Engine Types:Generally you will see words such as I4 turbo or V6 supercharged, or naturally aspirated V8. This is referring to how the engine gets its air intake for combustion. The naturally aspirated engine has no forced induction. This means that no device forces air into the cylinders and that normal atmospheric pressure and a partial vacuum are used to pull air into the induction tract. In a turbocharged engine, the turbocharger uses the engine exhaust to power a turbine which is used to force air into the cylinders. This also allows for more fuel and generates more power at higher efficiency. A supercharger operates much the same as a turbocharger, except it uses mechanical energy for power instead of exhaust. Turbochargers and superchargers can put a greater strain on an engine but generate a great deal more power compared to a naturally aspirated version of the same engine.
Other Terms: Two other terms you will see commonly used when hearing about engines is DOHC and VVT. DOHC stands for Double Overhead Camshaft, aka twin-cam, which means an extra camshaft is used over each cylinder head. The main benefit of this is that more valves can be used on the cylinder creating more power in a more efficient manner. VVT stands for Variable Valve Timing. There are many variations of this technology, seeming to differ depending on the manufacturer. What you basically need to know is that you typically get better engine performance and increased fuel efficiency.
Since the engine of a car can vary tremendously, it is important to know the basics. The type of engine you choose can greatly impact the price, performance, and fuel economy of your new car. If you remember even a few of the terms covered here, you will be a much more knowledgeable car shopper.