Hey just bought a used 2005 a4 1.8t from a private dealer. It has 153000km the oil has always been synthetic. Just wondering the best oil to use for the 1.8 turbo aswell as best filter, thanks.

 

Synthetic oil is recommended in part to help keep the engine from sludging up on the inside. We use Castrol 5/40 synthetic. Oil quality standards are 502 00, 505 01, 504 00/507 00 and these should be listed on the oil bottle, as it is on our oil. API rating is SM, SL/CF. This information might be in your owners manual so you can bring that in with you when you get your oil.

On filters I recommend OEM Audi. There are good quality aftermarket filters out there but it's hard to know which is best. Here is a good write up on oil filters that will help you make that decision. I think I got the link off this forum from another oil thread.

Oil Filters Revealed - MiniMopar Resources

In my opinion, for the usually small price difference between what in my opinion is a good quality aftermarket oil filter and the factory one, go OEM.

 

That was a very revealing article. Thank you for posting it.