V6 engine

A V6 engine is a V engine with six cylinders mounted on the crankshaft in two banks of three cylinders, usually set at either a 60 or 90 degree angle to each other. The V6 is one of the most compact engine configurations, usually ranging from 2.0 L to 4.3 L displacement (however, much larger examples have been produced for use in trucks), shorter than the inline 4 and more compact than the V8 engine. Because of its short length, the V6 fits well in the widely used transverse engine front-wheel drive layout. It is becoming more common as the space allowed for engines in modern cars is reduced at the same time as power requirements increase, and has largely replaced the inline 6, which is nearly twice as long - too long to fit in many modern engine compartments - and the V8, which is larger, more expensive, and has poorer fuel economy. The V6 engine has become widely adopted for medium-sized cars, often as an optional engine where an inline 4 is standard, or as a standard engine where a V8 is a higher-cost performance option.

The V6 is commercially successful in mid-size cars in the modern age of high fuel prices and price sensitive consumers because it is less expensive to build and has better fuel consumption than the V8, while being smoother in large sizes than the inline 4, which develops increasingly serious vibration problems in larger engines. The wider 90° V6 will fit in an engine compartment designed for a V8, providing a low-cost alternative to the V8 in an expensive car, while the narrower 60° V6 will fit in most engine compartments designed for an I4, proving a more powerful and smoother alternative engine to the four. While not perfectly smooth, the V6 is smoother than the I4 and adequately smooth for the average consumer. Buyers of luxury and/or performance cars who are not price sensitive or fuel economy minded might prefer an inline 6, which has comparable fuel economy and power but better smoothness, a flat 6 which combines better smoothness and often higher power with adequate fuel economy, or a V8 which has higher power, but worse fuel economy.

...
Wikipedia