Does API/ILSAC have a stay-in-grade requirement?

[crinkles]

So you may be aware Toyota Australia (Rightly or wrongly) specifies that a 5w30 is not to be used above 10 or so degree Celsius (call it 50 F). THis is for a 2AZ-FE engine.

One of the reasons for this discrepancy with the US market where 5w30 has been the going viscosity for years, I believe, is due to the difference in oil quality, base-stocks, or products that get offered in Australia. And hence, they do not want 5w30 Australian oils as they may shear down to a 20-weight. This requirement was from the early 2000's and I have seen it as late as 2010 in brand new 2GR-FE Highlander manuals.

Instead, 10w30 is recommended, and 15w40 and 20w-50 is also OK for 99% of the Australian landmass.

The other reason may be CAFE.

Now, I am perfectly happy to use a 5w30 if it meets stay in grade requirements, like A5/B5, which Mobil 1 is. (Also the only one I could find, others are A3 in this market for the most part).

I have very short trips in mild conditions (minimum 5 deg C winter, 20 deg C summer).

I can get plenty of 5w30's that are only SM/SN and ILSAC, but can't seem to find any stay in grade requirement in the API spec found here:
http://www.infineum.com/Documents/API/API Engine Oil Classifications 2010.pdf

When ACEA A5/B5 is talking "stay-in-grade" are they saying an oil won't shear down out of grade, or up? API only seems to have thickening limits, not any thinning of say a 5w30 to 5w-20.

THe other option is a dino SM/SN ILSAC 10w30, as I will be changing based on time (6 months). This may be more economical than trying an A5 or A3 5w30.


Using a 10w30 may seem obvious based on economics if i'm going by time - but - I am interested in the lower viscosity at startup. Using widman's calculator there is a factor of 1.5 in the viscosity between 10w30 and 5w30 at 5 deg C.

 

[tommygunn]

I've always wondered this myself. A lot of people when talking about 5W-20 like to quote the mantra of "most 5w30's shear to 5W-20 anyhow" and "most 5W-20's don't shear as much".

Reality is there should be specifications for this, otherwise its just "guess and test" as to what can shear where. I'd expect it to be tested, somewhere, since shearing out of grade can obviously have profound effects on oil performance.

Edit: And hard numbers. Not "the VI of this oil means it shouldn't shear much" and other armchair mechanics. If there really is no defined test against shear in API well...kinda makes sense why people wanna push new OEM specifications on owners sometimes.

 

[Falcon_LS]

If you take a look at this document, it appears to list the "stay in grade" limits for each API category/classification.

Originally Posted By: crinkles
Instead, 10w30 is recommended, and 15w40 and 20w-50 is also OK for 99% of the Australian landmass.


Exact same requires for the Middle East, although 5W-40 and 10W-40 are also permissible.

My company car is a '11 Land Cruiser Prado with the 1GR-FE, and I use Motorcraft Syn Blend 10w30. It's 60% Group III from what I read here and only costs something like $3.00 USD per quart. The 20W-50 used at the dealer made me cringe.

I considered an ACEA A3/B4 or A5/B5 rated 5w30, but they all come as synthetics and Toyota require the oil be changed every 5,000 km for warranty purposes. Quite wasteful to be changing out a synthetic at these intervals.

 

[toyota62]

I just had a look in my 2012 RAV4 owners manual.The same engine as yours.(2AZ-FE) It says 5w30 preferred.

 

[Tom NJ]

As Falcon noted in his link above, the Sequence VIII engine test, which is required for SN/SM and ILSAC, has a stay in grade requirement.

Tom NJ

 

[jorton]

"I'd expect it to be tested, somewhere, since shearing out of grade can obviously have profound effects on oil performance."

If that's true for your application you can run the Mobil 1, or an hdeo 5w30 like Amsoil or 10w30 like Shell Rotella 10w30.

 

[supercity]

I have a 2000 Rav4 with 1AZFE engine. There is a note on the back cover of the owners manual to use 10w30 if operating conditions are over -18. However it does not say anywhere not to use 5w30. 5w30 is preffered in cold conditionns bla de bla.

 

[TFB1]

Originally Posted By: tommygunn
I've always wondered this myself. A lot of people when talking about 5W-20 like to quote the mantra of "most 5w30's shear to 5W-20 anyhow" and "most 5W-20's don't shear as much".


Posters that beat their chest and spew this garbage, should have probably have been politicians...

Since many 5w30 aren't much more than a thick 20W, shearing one cSt could make it a thick 20W... All the 20w I've seen are at the thick end of the range, so that same one cSt shear would make it a medium grade 20...

 

[crinkles]

Originally Posted By: Tom NJ
As Falcon noted in his link above, the Sequence VIII engine test, which is required for SN/SM and ILSAC, has a stay in grade requirement.

Tom NJ


Thanks, I see that now.

I also see the API and ACEA use different stay in grade tests, ASTM D6709 and D6278 respectively. Which is tougher ?

 

[Tom NJ]

ASTM D6278 is much more severe than ASTM D6709 (Sequence VIII). Because it is more severe, the specifications are more loose. Under the API rules, an XW-30 is allowed to drop to 8.5 cSt under 6278, versus 9.3 under 6709.

ASTM D6278 is only allowed under API 1509 rules if an oil fails the shear specifications of D6709 but passes all other parameters.

Tom NJ

 

[A_Harman]

The API specifications for HDEO's explicitly state shear stability requirements, but the ASTM spec changed for CJ4. Up to CI4+, the spec was ASTM D6278. Now CJ4 specifies ASTM D7109. How much different are the two?

 

[Tom NJ]

ASTM D7109 is essentially the same as D6278 except that D7109 measures shear after 30 and 90 cycles, while D6278 uses only a 30 cycle run. The 90 cycle run should be more severe, but specifications may be adjusted to account for this.

Tom NJ