No, 0W-40 is a fully synthetic oil, while most 10W-40 oils are non-synthetic (conventional, or "dino"-saur) & a few might be semi-synthetics.

What are the differences? Let's take 10W-30 as an example. The rating only means that the oil flows like a frozen 10 wt when it's really cold (minus 20°F) instead of a frozen 30 wt (which would be thicker than you'd like at minus 20°F) & then behaves like any 30 wt would when it's hot (210°F & hotter). 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 than ANY OTHER motor oil will be above 210°F!! What does THAT really mean? It means the "thinnest" 0W-20 will be thicker for all of your cold starts than the "thickest" 15W-50 will be once it's flowing & the engine's warmed up to operating temperature!

5W-30 & 10W-30 are both "thinner" & provide less turbo protection than M1 0W-40!! The best turbo-protecting synthetic oil you can use is 15W-50. (As long as it doesn't get below, say, +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.

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! Any of these three Mobil 1 oils (15W-50, 5W-40 or 0W-40, or comparable oils from Amsoil) are your best bets.

posted by 146.82.1...

• Shopping for fully synthetic oil: 5-30? or 10-30?, Carolyn, Thu, 21 Apr 2005 11:29:40
  • Of 30 weight oils, 10W-30 is preferable to 5W-30, J, Fri, 22 Apr 2005 07:09:20
    • Hae Jae! Long time no oil!, Eiron, Fri, 22 Apr 2005 12:08:14
      • I really miss our verbal jousts. Though I remember ..., J, Mon, 25 Apr 2005 10:24:48
      • Yup, those days are gone. <sigh>, J, Mon, 25 Apr 2005 10:21:09
  • AMSOIL is better than Mobil 1, Dick in Falls Church, Thu, 21 Apr 2005 20:16:02
    • Does that carry the ACEA3 designation? and, TimBrown, Fri, 22 Apr 2005 07:11:33
  • Yet another suggestion, Eiron, Thu, 21 Apr 2005 13:00:58
    • TRUCK SUV OIL - Whats up with that? just marketing?, WFVIGGEN, Fri, 22 Apr 2005 08:22:21
      • Yes, just marketing, Eiron, Fri, 22 Apr 2005 08:46:16
        • Mobile 1 5w-30 currently, WFVIGGEN, Fri, 22 Apr 2005 09:25:23
          • Yes, IMO, Eiron, Fri, 22 Apr 2005 10:34:29
    • ?? you list #2 and #3, TimBrown, Thu, 21 Apr 2005 13:10:45
      • See Ian go!!, Eiron, Thu, 21 Apr 2005 14:54:45
  • None of the above, Stephen Goldberger, Thu, 21 Apr 2005 11:38:55
  • consensus is 0-30 (more), TimBrown, Thu, 21 Apr 2005 11:37:41
    • 0W-30 is only ACEA A5/B5. n/m, J, Fri, 22 Apr 2005 07:10:54
    • Re: consensus is 0-30 (more), Duhey2 , Thu, 21 Apr 2005 11:40:40
  • Re: Shopping for fully synthetic oil: 5-30? or 10-30?, GaryH, Thu, 21 Apr 2005 11:34:04
  • I've been reading 0W-40...more, Duhey2 , Thu, 21 Apr 2005 11:33:48
    • confused 0W-40 is 10w-40?, Carolyn, Thu, 21 Apr 2005 14:13:28
      • Hot/cold multi-viscosity explanation, Eiron, Thu, 21 Apr 2005 15:13:19 <-- Viewing This Message
        • you really ned to look at the bottle for the ACEA3, TimBrown, Thu, 21 Apr 2005 16:13:34
    • I think Duhey2 is correct, I'm wrong, ACEA3 IS correct, TimBrown, Thu, 21 Apr 2005 11:41:43

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: Interesting., patrickem, Thu, 21 Apr 2005 15:01:43
• Next by Date: Could not agree more, Louis, Thu, 21 Apr 2005 15:15:10
• Main 9⁵ 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)