Which is better, Mobil1 0w-40 or 10w-30?

[TSoA]

I would tend toward the 0w-40 because I mostly maintain European cars. Many of them are older and have 100k+ miles though, the 10w-30 would possibly not dissapate as quickly in cars that don't get their oil checked frequently, like mom's. Less VI means less "evaporation", right? The 10w-30 is only $3.75 by the jug. If I am paying $5 a pop I would buy German Syntec over M1 0w-40 anyway, correct?

[ August 15, 2003, 06:13 PM: Message edited by: TSoA ]

 

[moribundman]

Hey Audi Junkie,
The M1 10W-30 will not meet the HTHS requirement of your Audi. The 0W-40 will meet the required specs, but I'd prefer a 5W-40. Use an A3-rated oil. Right now it looks like Lubro Moly or Pentosynth 5W-4o are the best options for my 2.8. I'm still looking, though...

 

[Cary]

My experience with the 0w-40. 1996 Toyota Landcruiser, 118,000 miles, 0w-40 works great, zero consumption. 1994 BMW 525i, 102,000 miles, 1 quart every 750 miles. I would tend to lean towards the heavier oils for older europeon cars, i.e. 15w-50 Mobil 1, Redline 5w-40, 10w-40.

 

[Jay]

I think the choice comes down to shear-stability vs cold temp performance and which one you feel is most important.

 

[TSoA]

My 30v is a 1998, 12v a 1995, and the I-5 is a 1987. Is HT/HS a requirement before 2000? ACEA 3 is basicly only 40w anyway save 1 or 2 oils?

 

[buster]

Looking at specs, yeah the 0w-40 would be better. But in all honesty, I don't think there are many (if any) better oils then Mobil 1 10w-30. It has proven over and over again that it is as shear stable as any. I don't think there has been one case yet where M1 SS thinned out. Can you tell I'm a big fan of the 10w-30?

 

[moribundman]

Audi Junkie,

Your 30v, 12v, and the I-5 all should use oil that meet VW502.00 or VW500.00. That said, as you know from AW, many of the Audi guys use M1 10W-30 seemingly without harm. Is it a problem that the M1 10W-30 has an HTHS lower than 3.5? I don't know, but at high oil temperatures HTHS might be a critical issue. Now, I'm not bold enough to take a chance. If you go to the AW 12v forum, they'll probably tell you to use 5W-40 or 15W-50 in your 12v.

[ August 15, 2003, 10:02 PM: Message edited by: moribundman ]

 

[buster]

quote:

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Is it a problem that the M1 10W-30 has an HTHS lower than 3.5?

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Thats a good question. Even though the 0w-40 has a higher HT/HS, its not as shear stable as 10w-30.