V6

Straight-six engines were historically more common than V6's, mainly because the length of such engines was not such a concern in rear-drive vehicles but also because V6's (unlike the 90-degree V8) were somewhat difficult to make smooth-running. The widespread use of front-wheel-drive and "east-west" engine configurations saw that the shorter engine length of the V6 became highly desirable, and these days most six-cylinder engines are made in the V configuration (in fact, the Australian Ford Falcon[?] remains one of the very few straight sixes still in use in contemporary passenger vehicles (oh, and some Mercedes and BMWs)). (Mercedes have recently give up the staight six, and now only engineers V6 engines).

To confuse matters somewhat, Volkswagen have produced an engine called the VR6 see Straight engine. This allows a 6 cylinder engine to be squeezed into the space of little more than a 4 cylinder engine. Unlike a traditional V6 however all 6 cylinders share the same cylinder head. To take this analogy further they also have designed and produced a W8/W12/W16 range of engines with the W12 being two VR6 type cylinder heads arranged in a vee, hence the W!

see also V12