Hello all, I have just recently purchased a new S8 and am very excited.The one thing I could not find in the manual is the type of oil the S8 used.If any owners can let me know I would appreciate it.

http://microsites.audiusa.com/ngw/09/media/downloads/pdfs/Audi_TechnialServiceBulletin_1997-2010.pdf

In plainer English, newer Audis use synthetics. Audi tends to focus around 5W-40 oil, though that isn't very common among US available brands.

The oil specs have changed again, but the long life group is where you find the most stringent quality. Look in the attached in the 504/507 group. Similar to the 503 grouping previously. The two I have found that get to the tighter specs are Mobil 1 0W-40 and Castrol Euro formula 0W-30. Do not get fooled by other Mobil 1's like 0W-30 or 5W-30 commonly available at US parts stores, Costco, Wally World etc.; they aren't up to the same spec. Ditto on Castrol; it has to be the one labled Euro formula that is made in Europe. Audi doesn't commonly recommend a 0W-30 oil in the US, though in Europe they specifically did for the 450HP verson of the W12.

Net, Mobil 1 0W-40 for me unless I know I am in a 6 month non summer change cycle where I would use the Castrol. Mobil widely available at most parts stores in that grade. That Castrol is available commonly only at Autozone, at least here in N. California.

all NAPA (Never Any Parts Available) distribution centers stock Valvoline full synthetic with the VW 502 / 505 / 505.01 designator. Bottles say "European Formula". It is made in the USA.

Larger stores usually stock it. Smaller stores will have it the next day as NAPA has a fleet of trucks that make nightly deliveries at least 5 days a week.

Most VW and Audi dealers stock the Castorol brand in individual bottles. Not sure what they buy in bulk.

Also, Shell Rotella (diesel truck engine) oil is common in 5W 40 grade and some Costco's stock it. Beware, it does not meet any of the VW standards as it is a fossil oil.