Which Oil?

[tflis007]

Yesterday i bought my first Audi A6 C6 2007 2.7 TDI Quattro automatic 148K miles. Can you please recommend what oil should i use?
Audi recommends 5W30 but i read the post somewhere that 5W40 gives much better fuel economy.
When I had a VW passat it was very important to use the oil with spec 505.01. But when I asked Audi service about the spec of the oil for my A6 they had no idea what i'm talking about. Is that not the case for Audi?
I'm looking on Castrol Edge Titanium FST. Is that a good choice or for some reason not?
How much oil should I put in? I found information starting from 7.2L up to 8.5L.


HELP!!!

[Magnet]

Hello, If the handbook recommends 5w30 then personally I would not see any reason to use any other grade. Using 40 would in no way aid better fuel economy. 

Brand? I have always used Quantum oils in our petrol Audi - reputed to be manufactured by Castrol. I use their Longlife 3 even though I change it annually. This brand was/is recommended by Audi, and you will find it mail order on the famous auction site. 

Kind regards, 

Gareth. 

[niedzial1983]

You need 504.00 / 507.00 spec for 2.7 diesel . You will not see any economy gains between 5w30 or 5w40