The engine is the part of a vehicle that burns fuel and converts it into mechanical power. In most vehicles, this is done using an internal combustion engine, which ignites fuel and uses it to move mechanical parts. Most engines of this type burn gasoline to drive pistons up and down, which turns the crankshaft and, eventually, gets the vehicle's wheels moving. Engines are most commonly measured by their number of piston cylinders and the amount of volume contained in those cylinders.
Most engines have designations such as V8, 4-cylinder, or V6. The number represents the number of pistons, while the V refers to the cylinders' alignment. In a V-type engine, piston cylinders are positioned in a V shape.
Inline engines, such as an inline 4-cylinder, have all cylinders running parallel instead of being divided equally on each side and placed at an angle. Vehicles with more pistons typically have greater combined internal volume and produce more power.
The second designation on most engines is volume capacity. Modern engines typically have a capacity from 1.5 to 6 liters, though larger and smaller volumes are available. Because the available volume directly affects the available mechanical energy of the piston, higher volumes translate directly into greater raw power. The volume capacity is reached by totaling the volume of all piston cylinders.
Technological advances have greatly changed how fuel is pumped into an engine and how exhaust is handled. VTEC engines, for example, use advanced variable valve lift timing and electronic control to carefully monitor exactly how much fuel enters each cylinder and how much waste remains after each revolution. This allows engines to maintain peak efficiency by burning as close to the exact amount of fuel needed as possible on each revolution.
A more powerful engine might be just what you need if you regularly haul heavy loads with your car or live in areas where hilly or otherwise difficult terrain is common. Smaller engines typically have less volume in each cylinder and fewer cylinders. This lessens the overall power of the car, but will save you money every time you fill up.
Choosing the right type of engine for your needs is a major consideration when buying a new or used car. Manufacturers create a wide selection of engine types for most vehicle models and years, and knowing the differences between engine types and sizes can ensure that you get the right car for you.