I made a Video a year ago when i reported the glitch.
It is in german but you will get the point.
Engines 100% when in group. Normal when not.
Tested on Scripted Altis Life server.
https://www.youtube.com/watch?time_continue=100&v=hGSGPnrZnT8

This Glitch is still happening and its very frustrating to land this thing.