0W-20 required for emissions certification

[Gokhan]

Originally Posted By: Ram01
Will 0w20 oil protect in the summer heat?????

It will protect better than a dino 5W-20, as the two have the same or very similar 100 - 150 C viscosities and yet the synthetic 0W-20 will resist oxidation better than the dino 5W-20, especially in high-temperature conditions.

In many ways, this question is similar to asking if a synthetic 5W-30 instead of a dino 10W-30 will protect in the summer heat. The answer is the same as above. (It wouldn't be the same answer for a dino 5W-30, as it would shear a lot more than a dino 10W-30 and be much more volatile as well.)

 

[The Critic]

Originally Posted By: PandaBear
But so far I've not seen any non synthetic 0w20.


Honda's bulk Genuine Honda 0w20, which is used by almost all dealers, is synthetic-blend.

 

[Gokhan]

Originally Posted By: The Critic
Originally Posted By: PandaBear
But so far I've not seen any non synthetic 0w20.

Honda's bulk Genuine Honda 0w20, which is used by almost all dealers, is synthetic-blend.

Yes, while you cannot meet the API requirement of maximum 15% NOACK volatility with a Group II+ 0W-20, it's possible to meet it with mixing Group II+ with III and/or IV. They also have such 0W-20 in Canada.

It's too bad that Honda is going synthetic blend with 0W-20 instead of full synthetic. Cheapskates... That's why Toyota is No. 1.

 

[tudorart]

Originally Posted By: Gokhan
There are often typos in the datasheets; therefore, I wouldn't be surprised if Pennzoil had a typo with the temperature.

These are the SAE viscosity specs:

Code:


Grade CCS (cP @ C) MRV (cP @ C) KV100_min (cSt) KV100_max (cSt) HTHSV_min (cP)



0W 6200 at -35 60000 at -40 3.8 - -

5W 6600 at -30 60000 at -35 3.8 - -

10W 7000 at -25 60000 at -30 4.1 - -

15W 7000 at -20 60000 at -25 5.6 - -

20W 9500 at -15 60000 at -20 5.6 - -

25W 13000 at -10 60000 at -15 9.3 - -

20 - - 5.6
30 - - 9.3
40 - - 12.5
40 - - 12.5
50 - - 16.3
60 - - 21.9 pre>


I believe MRV values (low-temperature pumping viscosity) are easier to attain but the CCS values (low-temperature cranking viscosity) are harder to attain. This may be the answer to your question.




The MRV spec was introduced because the data provided by CCS was not sufficient in the past. I don't remember which major brand had a series of engine failures due to pumping issues in the winter even though the CCS was below the starting temp.



They wanted a new test that will take into consideration the SLOW chilling of the oil...which in some circumstances can develop some wax crystals IIRC even if passing the CCS test for that same temp.



The reason it's -5C less it's just a safety margin because you don't want an oil to allow crank and not pump.



This is from the top of my head but the exact incident with the failing engines and history of MRV test is on Google somewhere.



I also think MRV is an complementary test to the CCS and it's there to exclude a few exceptional problematic oils that would not pump well for their CCS rating.