Volkswagen’s VR5 engine was a truly unique piece of automotive history.
Everybody knows what a V6 engine is. Same with an inline four-cylinder engine. Some might even know what a boxer engine is, with a few even being able to name cars that feature a rotary engine.
But what if we went back to a strange era in automotive design when Volkswagen was toying with power levels between an inline 4-cylinder and a V6 engine? Turbochargers had yet to come into their own as a method of shoring up a 4-cylinder’s power output, so to make some of Volkswagen’s smaller cars have a bit more punch they needed to come up with something else.
Volkswagen already had an engine that was sort of in between: the VR6 engine. Like a regular V6 engine it had 6 cylinders in the vague shape of a V but they were all squished closer together. The cylinders were offset slightly and tilted at 15 degrees. This made the engine smaller and lighter than a regular V6.
So when it came time to consider a smaller engine than the VR6, VW did the natural thing and lopped a cylinder off.
The VR5 is just like a VR6 only it has five cylinders instead of six. And what immediately comes to mind is the fact this engine is uneven and weird. Since one side of the engine has more mass than the other it has an odd vibration, and since some of the exhaust and intake tracts are longer than the others, it also has a unique idling sound, almost like the engine is burbling.
Jason Fenske at Engineering Explained on YouTube once again does a fantastic job explaining the operation of such an engine and some of it's more unique design elements.
The VR5 saw use in the late ‘90s and early 2000s, find its way into MK4 Golfs, Jettas, B5-gen Passats, and the new Beetles. They were eventually replaced by inline 4-cylinder engines with baby turbos in them that provided similar overall power output but were lighter than the V5.
And now the turbocharged inline 4-cylinder might die off to the hybrid electric engine. Such as the circle of life with automotive technology.