For anyone interested in a comparison I have recently moved on from my 2004 1.6 TDCi LX with 72k miles to a 2009 1.8 TDCi Zetec just 2k miles,a channel island import via a local ford dealer with a service franchise (but not a sales franchise).Some of the differences surprised me.
The 1.8 seems to be put together noticably better,even allowing for the fact it is nearly new as compared to a 72k mile car.No squeaks or rattles at all so far which certainly cant be said for the 1.6 when I first got it.
The figures on paper for the 2 engines suggested I would notice little difference in performance but suffer a drop in economy.In practice it is the opposite-there is noticably better acceleration and economy seems about the same-for mixed motoring including a 20mile journey to and from work weekdays in traffic about 47-48 mpg.
I've seen some reports suggesting the 1.8 is noisier.Dont think so though it has a slightly different sound-once on a run and in 5th if anything it is a little quieter.Under the bonnet there does seem to be a much bigger cover on the engine which may explain why.
The slight lag in acceleration on moving off is still there-you get used to it but still have to watch out sometimes e.g. when trying to pull away quickly at a roundabout.keep those revs up!
One strange thing-there seems to be slightly less room in the drivers footwell.When stretching out my left foot I can catch the clutch pedal with the inside of my shoe.Odd.Perhaps I'm imagining it?Is the centre console slightly bigger?
All in all the latest version is a worthy improvment on the earlier version to my mind building on all the good points and hopefully sorting out all the early niggles.Time will tell.