How do multi-grade oils apply to engines in general, & Saab turbos in particular? Let's take 10W-30 as an example. This rating only means that the oil flows like a frozen 10 wt when it's really cold (0°F) instead of a frozen 30 wt (which would be thicker than you'd like at 0°F) & then behaves like any 30 wt would when it's hot. The COLD RATING (xW- end of things) should be viewed as being COMPLETELY SEPARATE from the HOT RATING (the 30, 40 or 50 wt part) & is simply a labeling convenience to help you pick an effective oil for your start-up climate. The hot rating is where you'll get all your operating temperature protection, & should be chosen based on the engine's design & protection needs. Separate them in your mind!

Done that? OK, good! Now consider this: ANY motor oil will be thicker below 100°F (100°!!) than ANY OTHER motor oil will be above 200°F!! What does that really mean? It means the "thinnest" 0W-20 will be thicker for all of your cold starts in Raleigh than the "thickest" 15W-50 will be once the engine's warmed up to operating temperature! Once your engine's going, 5W-30 & 10W-30 are both "thinner" & provide less turbo protection than 0W-40!!

For Saab turbos, you really want to stay with an ACEA A3 rated oil. This is the most durable High Temperature/High Shear (HT/HS) classification, & ensures the oil will survive the harsh environment of your turbo. Operating at well over 400°F & 100k rpm, turbos are THE definition of HT/HS! The best turbo-protecting synthetic oil you can use all year long in your climate is 15W-50. (As long as it doesn't get below +20°F, you're fine.) Colder than that (regular drops down to 0°F) & 5W-40 would cold-flow better but still offer great turbo protection. Colder still (maybe routine minus-20°F mornings) & 0W-40 would be your first choice. Any of these three Mobil 1 oils (& comparable oils from Amsoil) are your best bets.

posted by 146.82.1...

• Can I use 0W-40 100% synthetics oil in Winter?, Pat98, Sun, 5 Dec 2004 12:10:24
  • Thanx All! I will switch back to 40 (or 50) oil =) nm., Pat98, Mon, 6 Dec 2004 12:30:18
  • What Dick said AND what zeke said (& longer than both!), Eiron, Mon, 6 Dec 2004 09:12:10 <-- Viewing This Message
  • Yes--either will be fine n/m, Dick in Falls Church, Mon, 6 Dec 2004 08:31:52
  • At that latitude, I'd use M1 15W-50 year-round....., zeke, Sun, 5 Dec 2004 14:37:08
  • use whatever you want., Andrew , Sun, 5 Dec 2004 12:43:32

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.

• Prev by Date: Re: '93 9K CSE Turbo TCS System, David Ingram, Mon, 6 Dec 2004 09:07:48
• Next by Date: SRS Update, Mike Johnson, Mon, 6 Dec 2004 09:16:53
• Main 9000 Bulletin Board

StateOfNine.com

SaabClub.com

Jak Stoll Performance

M Car Covers

Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2024 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)