I have the pre reg T6 Euro5 102bhp and can tell you the engine layout looks different to my previous T 5.1 Euro 5 albeit probably the same parts but updated as my T6 is like night and day smoother than the 5.1
.I heard they'd insulated them better but the gearing and pulling away at the lights is so much more refined,the 5.1 was a little shall we say agricultural.