actually, 1.8 is not a real TDCI engine
TDCI engines are 1.4, 1.6 and 2.0 . all of them were developed by Ford togheter with PSA(peugeot + citroen).
the 1.8 "tdci" is actually a 1.8 tddi (Endura-D) upgraded with a variable-vane turbocharger and a Delphi common rail injection system.
I've tried all of them (I had 1.4 on a Fiesta, I have 2.0 on Cmax and I've tried 1.6(both 90 and 109 hp) and 1.8 on the romanian ford club meetings) and I think that 1.8 has more noise and trepidations, compared to the "real" TDCIs