i know its probably been asked before but i am considering changing the 2.5 for a 200tdi as it will couple straight to my lt77 gear box and are reasonably however as i use the land rover on the motor way to get to events i am wondering how the top end speed will be improved by just changing the engine as at the mo anything over 55 is a bit hairy and very loud and sounds like the engine may fly out from the bonnet at any time .also as the 200tdi is only really a upgraded version of my current engine is it worth it or is the 300tdi and matching gearbox a better option although much more expensive any help much appriciated