That title goes to Mercedes-Benz and their  2.0L 4-cylinder turbocharged engine found inside the CLA 45 AMG.

355 hp
332 lb.ft of torque
0-100 km/h in 4.6 seconds
Top speed – 250 km/h
Engine is hand-built, start to finish, by one technician

Starting at $50,600
Sold out in Canada

(pictured above is a CLA 250, but the AMG looks similar enough, with the main difference being the badge on the back)

(non car nerds: AMG is Mercedes’ line of high-performance vehicles, see this chart)

(to be clear – the post title refers to a “production engine found in a consumer vehicle”)

(I did not mean for this post to have so many brackets)