inquires about engine oil
 

My AUDI A4 was installed EA888 GEN3 Engine ( 140KW, Engine code CWNA). I was recently noticed that this engine perhaps apply Audi B cycle tech, Audi suggests to use 0W20 oil and standard meets to VW 508. can anyone tell me whether i can follow this oil?

What's in you car manual? I thought it is spec VW504...

The factory user manual suggest to use oil standard meets up to VW 502 or VW504. But, the Newest Audi maintenance schedule introduces the engine with B cycle technology should use 0W20 viscosity as per VW 508 oil standard, especially Audi is using B cycle to EA888 GEN3 engine with low power already, I knew my Audi have EA888 GEN3 engine, but i couldn't certain whether I should use 0W20 oil.

502 oil has greater film strength than 5w-20. This helps keep metal from touching metal. Run Castrol edge 0w-40 and dont worry about it.

Audi/VW recommendation -- "B-Cycle and 3.0 Turbo (S4, S5, SQ5) Gasoline Engines:Audi oil standard VW 508.00". Yes, 508.00 is 0W20 and it can save gas to match the whole purpose of B cycle engine which is to save gas. However, the 508.00 standard has a lot more than just save gas -- it's the additive package to keep the engines clean. Otherwise, they wouldn't let a thin 0W20 oil be used in high performance 3.0 Turbo engine for those S model cars. If I were you, I would stick to the Audi's spec and use 0W20 oil which meets VW508.00 standard (note: not all 0W20 oil meets VW508.00 spec). They designed the engine to handle the thin oil.

Zheng, I don't know what country you are writing from, but Audi places a label under the hood that describes which oil standard should be used. It's typically on the plastic panels above the area where the radiator sits.

You are correct, although the engine is the EA888 Type3-B, which is the B-cycle version, and your engine code of CWNA is also correct for that engine:
https://cimg4.ibsrv.net/gimg/www.aud...e2dafbf0d1.png
Source: erwin.audi.com

And Minmet's post is accurate:
To add to Minmet's post, there are 3 B-cycle engines - EA888 Type3-B (the original B-cycle design, on which most of the patents are based), the EA838 3.0 litre TFSI single turbo TFSI, and the EA839 2.9 litre TFSI twin turbo. All now used in quite a few VAF models. All Audi designed. Agree that 508.00 is not just saving fuel, these engines have variable valve timing and variable compression, so playing with oil viscosity not a great idea. Use VW508.00.

Our B9 S5 cabriolet came from the factory with a 504.00 label in the engine bay. They must have run out of the 508.00 ones at Neckarsulm, or not had any there at the time - cabriolet the only version made there, all others at Ingolstadt. Zheng pretty smart to double check!

The 502 (5w40) spec is dead now. You'll have 508 (0w-20) for the B-cycle motors and 504 (5w30) for the rest in the US. Factory fill on everything but the B-cycle motors is 0w30 (also a 504 spec).