Whilst the 2.0 is the most up to date of the engines, it is not fundamentally different from the 1.9 and has been in production for less than a year so examples are going to be harder to find and more £££'s.
Main changes on the 2.0 are a 1mm overbore (83mm x 90.4 mm stroke) compared with 82x 90.4 to give a capacity increase of 46ccs, a lower compression ratio (16.5:1 instead of 17.5:1) , a close-coupled DPF configuration (theoretically giving better regen performance) and importantly, different mapping to give extra bhp and torque and Euro 5 emissions. Maybe the turbo is different but I haven't checked that yet.
The real change in diesels will be when the engine gets Multijet ll which without any major mechanical changes, increases the number of injection pulses from 5 to 8, allowing more control over the burn, helping emissions and power. (For the record the original JTD had 2 injections per cycle - one for noise reduction, one for power). This is likely some time in 2010.
In the meantime, with the exception of the DPF changes, a 1.9 can be remapped to give better results than a stock 2.0. The performance increase on a 2.0 litre is not likely to be as dramatic as effectively you already have a mild remap in place and you only have an extra 46 cc's to play with.
For real performance you should go to the 2.4 but don't be expecting amazing fuel consumption and if you do a lot of short runs, your DPF will spend a lot of time regenerating (common to all these engines)
Last edited by ukmike2008; 24-02-10 at 09:53.