5W30 Dexos vs. 10W30

[SR5]

Originally Posted By: Garak


SR5: There's certainly nothing wrong with an ILSAC 5w30 (or 10w30) where specified.…

Like I've said before, when a parts man told me that 0w-40 was too thin for my Audi but an ILSAC 10w30 was not, well, that tells it all.


What !!!! He told 0W40 was too thin, but ILSAC oil is OK !!!

Some of the things you hear from people in the trade. It must be hard for the aveage consumer to filter good advice from bad advice, because both is regularly given. I've stopped trying to explain things back when faced with the same situation. I just politely listen, say thanks, and follow my own logic. They are trying to help, and they don't know me from Adam.

Yes, keen to give a Dexos 5W30 a go. And if I had a Honda or something, I would. But my GM / Opel car OM says to use a A3/B3 or A3/B4 oil. And I do like A3/B4 oil, so it's hard not to just do what they say.

Here are some HTHS values
Mobil 1 5W30 (ILSAC) 3.09
Castrol EDGE 5W30 (A3/B4) 3.6
Mobil 1 0W40 3.8
GTX 15W40 3.95

The Castrol EDGE 5W30 is a nice oil, at the very lightest end of A3/B4 (min 3.5), but the two Mobil 1 oils you can get, offer ample choice for most people. I would be happy ( errr...satisfied) if I had easy (and affordable ) access to those two. Still, I do like where the Castrol EDGE 5W30 A3/B4 sits, a good middle weight oil.

 

[Garak]

Originally Posted By: Ducman
It's the whole Xw-XX rating thing that's the problem. The system certainly served it's purpose back in the day when mineral oils ruled the landscape.

It even had its problems in the day, particularly when 10w-40 was allowed to have an HTHS of only 2.9. Nonetheless, part of me joining, and lurking even before, was to learn those things I didn't know. I did pay attention to specifications and knew the difference between the part before and after the "w" and knew that an HDEO would be thicker than "something else" of the same grade, at least in North America, thanks to my dad, but, this place has been great.

Originally Posted By: SR5
What !!!! He told 0W40 was too thin, but ILSAC oil is OK !!!

Yep, he did at that. On the other side of the coin, there was a lady here who worked at an oil shop, which unfortunately no longer exists, who knew every European specification and what oils she had that met them right off the top of her head.