Editing Straight-six engine (section)

{{Short description|Internal combustion engine}}
{{Use dmy dates|date=October 2020}}

[[File:M20B25 block.jpg|thumb|right|Engine block of a [[BMW M20#M20B25|BMW M20]] straight-six engine (top view with cylinder head removed)]]

A '''straight-six engine''' (also referred to as an '''inline-six engine'''; abbreviated I6 or L6) is a [[piston engine]] with six cylinders arranged in a straight line along the [[crankshaft]]. A straight-six engine has perfect primary and secondary [[engine balance]], resulting in fewer vibrations than other designs of six or fewer cylinders.

Until the mid-20th century, the straight-six layout was the most common design for engines with six cylinders. However, [[V6 engine]]s gradually became more common in the 1970s and by the 2000s, V6 engines had replaced straight-six engines in most light automotive applications.