JoeP1

The standard oil change by Audi is every 10K miles. I have just changed to synthetic oil (Castrol Syntec 5W-40). What is the recommended oil change interval with synthetic?
Joe

SouthboroAudiGuy

From Bentley Publishers<ul><li><a href="http://www.bentleypublishers.com/images//tech/audi/audi.2003.maintenance.sched.pdf">KLICK</a></li></ul>

cruzan

Seems everyone has their own opinion on oil brands and interval changes. Here is what I have investigated. I too have been running synthetic oil (Amsoil is my choice). I've heard that even with synthetic, some are doing a full change (filter and oil) at 5 k mi. I pulled a sample of oil (with 5 K on it) and sent it to "Oil Analyzers" . The report came back and I called their tech. group to discuss it. BAsically there are 2 sets of data (one the contamination in the oil the other the chemical/protective properties. After 5 k the oil (despite looking dark- which is very common for all types to turn quite quickly) was really in good shape. The TBN # (total base number) was at 5.X (new I believe it's at 10 or 12 for that grade/type). The TBN drops off quickly initialy then will level and fall off gradually. I was told I still had at least another 5 k mi (assuming similar drivinf conditions) before I should change. Amsoil recommends on a gas turbo engine - 10 k mi or 1 year (for severe catergory because of the turbos). You could probably do the same with your synthetic oil. Some may also suggest a oil filter (only) change at 5 k mi, then a full change at 10 k. Oil is somewhat inexpensive , however at almost 7 qts and $10 for the filter it's still a $50 + change.

Regards

LuvnhatemyA6

Right now I'm doing 6K which is probably slightly too frequent, 7.5K would work.

The Mahle filter is labelled 2 year, extra long life, so 7.5K for this filter should be fine.

john in cincy

How do you do a "filter only" change? In any event, every 10k full synthetic is more than fine.

LuvnhatemyA6

You unscrew the filter and fit a new one. Top up the oil.

Ritz

I've been doing M1 5W-40 &amp; mahle filter every 5K, but am considering going to 10K.

john in cincy

first filter only I have ever heard suggested.

Ritz

says so right on the filter. Your serve.