Forgive a new Fabia owner his ignorance but why does one hae to use anexpensive special oil for this engine? I have to keep a bottle in the car as apparantly any other oil (even very good multi grades ) can wreck the engine

You just do. Not sure on the technicalities, but it might be to do with lubricating the high pressure fuelling system. You can probably get away with having a non PD 5w 40 oil as a top-up, but services should be done with the good stuff.

No offence Matt, but it's already been answered in the other thread that you've created asking the same question.

http://www.briskoda.net/forums/fabia/pd-oil-matters/95882/

No offence Matt, but it's already been answered in the other thread that you've created asking the same question.

http://www.briskoda.net/forums/fabia/pd-oil-matters/95882/

No offence taken. I'm new to the forum. Thanks for bringing this up and sorry to waste anyones time. Couldn't locate the first thread for a while!