yes it has... my 15.6L engine had 408hp braking power maybe not extremely strong in comparison to a J-brake i suppose ,but SCANIA chose as far as i recall in the late 80s for developing a wearfree hydraulic brake (retarder)integrated in/mounted at the backside of their gearbox... adding an extra 610hp/3500Nm of braking power in my case. The latest 2021 version delivers up to 4700nm braking torque..... so their classic engine brake itself hasn't improved that much throughout the years because they didn't need to.