1994-2002 [Subscribe to Daily Digest] |
If you read thru the ACEA specs you'll find that A5/B5 is a weaker spec than A3/B3. The difference rests in the HT/HS (High Temperature/High Shear) requirements. A3/B3 has a much higher minimum threshold for retaining its viscosity properties under extreme HT/HS conditions; exactly the conditions a turbocharger creates. (A3/B3 must be >/=3.5mPa.s.; A5/B5 must be <3.5mPa.s. but not less than 2.9mPa.s.) A5/B5 specs are specifically for low friction/low viscosity oils used to promote fuel economy.
This is why Saab says to use A3/B3 oils rather than A5/B5 oils. There are very few xW-30 wt oils that meet A3/B3.
posted by 71.212.145...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.