What engine changes is Skoda making to meet the Euro IV Emission rules? What are the implications for fuel economy or performance?

For example, looking at the Fabia pages on the Skoda UK web site it now shows 70 and 80 hp PD engines (which I believe are the new ones), but I notice that they are consistently worse in terms of combined mpg, top speed and CO2 emissions figures compared to the "old" 75 hp engines. :confused:

What are the differences to the PD100 and PD130 engines - will they suffer in the same way under the new rules?

Is it a good time to buy a Fabia with the old Euro III engines (if any are left)?

Not sure what all has to change but I do know that in order to comply the OctyII has been fitted with a particulate filter. This is more complicated than it sound because it filters out particulates and then burns a lot of them off at a certain exhaust temperature. The 1.9 105bhp Golf IV got away without one due to it's reduced weight.

Can't the 1.9 PD130 be stright swaped for the 140bhp 2.0 Euro IV unit?

This link doesn't answer the engine changes question, but does show the differing emission requirements:

http://www.vcacarfueldata.org.uk/information/emissions.asp