(I've tried a search, however the forum search function isn't working at the moment)

My petrol 2012 A4 TFSi user manual says to use VW 504 00 engine oil 

What does this translate to -

5W-40 or 5W-30?

(I will be buying fully synthetic)

Thanks in advance,

Colin

Hello Colin, 

As far as I’m aware it equates to 5w 30 and not 5w 40, but hopefully someone else will be along to confirm or refute this. 
You say you be buying ‘fully synthetic’, but I would advise that ‘synthetic’ has become rather confused, and you now might encounter descriptions such as ‘synthetic technology’. 

Incase it helps, I have been using VAG’s recommended Quantum brand for many years - using their Longlife 3 variant, even though covering less than 10k per annum, and changing it annually. 
This is normally available at competitive prices from a number of EBay sellers. 

As well as investing in the correct specification and grade of oil, it is equally important to choose good filters. Your choice of course, but I stay well away from sellers who normally sell their products at high discounts off so called retail prices! 
Kind regards,

Gareth. 

Many thanks Gareth - I will take your advice 👍