Hi all,
I've been reading the posts of the BITOG forum for a few months now and what a great place this is! I've learned so much already. But now I decided that it's time for me to register to this site and post a question to which I haven't found a thorough answer yet.
So, the question is: What's the idea of 5W-30 oils with HTHS >= 3.5?
My question arises from the fact that my Nissan Primera's Owner's Manual recommends to use "API SG, SH or SJ, ILSAC GF-I or GF-II, ACEA A2-96" oil with 5W-30 grade (also xW-40 and xW-50 grades are allowed).
The ACEA A2-96 issue 3 specification requires that the HTHS must be at least 3.5 as seen in the ACEA Oil Sequences 2002 (Note: I couldn't find ACEA A2-96 issue 1 anywhere from the internet, but I'm assuming here that the issue 1 has also the same HTHS requirement).
As we can see from here the HTHS viscosity is the value which dictates engine oil's real viscosity, not the KV100.
Any idea why Nissan recommends such a goofy combination, a 5W-30 oil with HTHS >= 3.5? I don't think that the reason could be the same as in the relatively new VW504.00/507.00 specification (0W-30 or 5W-30 oil with HTHS >= 3.5), as the Owner's Manual refers to an age-old ACEA spec from 1996.
My guess for the VW specification is that it tries to force the oil manufacturers to use better quality VIIs (with less temporary and permanent shear) than what the 5W-40 oils have. And thus the VW504.00/VW507.00 oils would be more suitable for extended OCIs. Could this be the case?
I'm keen to hear your views and opinions on this subject!
I've been reading the posts of the BITOG forum for a few months now and what a great place this is! I've learned so much already. But now I decided that it's time for me to register to this site and post a question to which I haven't found a thorough answer yet.
So, the question is: What's the idea of 5W-30 oils with HTHS >= 3.5?
My question arises from the fact that my Nissan Primera's Owner's Manual recommends to use "API SG, SH or SJ, ILSAC GF-I or GF-II, ACEA A2-96" oil with 5W-30 grade (also xW-40 and xW-50 grades are allowed).
The ACEA A2-96 issue 3 specification requires that the HTHS must be at least 3.5 as seen in the ACEA Oil Sequences 2002 (Note: I couldn't find ACEA A2-96 issue 1 anywhere from the internet, but I'm assuming here that the issue 1 has also the same HTHS requirement).
As we can see from here the HTHS viscosity is the value which dictates engine oil's real viscosity, not the KV100.
Any idea why Nissan recommends such a goofy combination, a 5W-30 oil with HTHS >= 3.5? I don't think that the reason could be the same as in the relatively new VW504.00/507.00 specification (0W-30 or 5W-30 oil with HTHS >= 3.5), as the Owner's Manual refers to an age-old ACEA spec from 1996.
My guess for the VW specification is that it tries to force the oil manufacturers to use better quality VIIs (with less temporary and permanent shear) than what the 5W-40 oils have. And thus the VW504.00/VW507.00 oils would be more suitable for extended OCIs. Could this be the case?
I'm keen to hear your views and opinions on this subject!