I've recently purchased a 2001 A3 110bhp tdi sport and was wondering how to tell if it's the PD engine or the older unit. I was told that the older unit has 'clips' to remove the top engine cover and the PD engine cover is bolted down, is this correct? Mine is the bolt down type.

What are the main differences/advantages of the PD unit also? More efficient? Lower emissions? Direct injection?

My other question is about oil. I've just done an oil and filter change on mine this morning and going from my handbook i used VW spec 505 01 (I used Castrol edge 5W40 fully synthetic conforming to that standard). It also states that my servicing is 'fixed' and the 'longlife' service is not available for my engine. Soooooo, my questions are;

-What is the difference between the fixed and variable service?
-What is the longlife service?
-Why is the longlife service not available for my engine? (110hp, 82KW)
-What is the difference between the tdi group that means they must use different oils from one-another? I thought they were basically the same engine's but mapped differently?

Lots of questions i know, it just seems strange that there is such a variety of different oils for what i thought was the same engine, but in a different state of tune

I may have missed a big sticky somewhere and apologies if i have, maybe someone can point me in the right direction