thanks for the input so far guys.

the zetec is tunable and can get to about 270-280bhp, but not much more. whereas the duratec i have seen 300+ and that extra 20+ bhp can make a big difference.

although the car has gone on a diet already with more planned, one of the reasons for considering changing is down to the lighter engine helping to achieve my weight goals.

does anyone know the weight of the 2.0l zetec and duratec engines?
would help inform my decision.

interesting that the duratec was fitted to the focus in the US might make information easier to come by if i do go this route.