New oils get better....but cold specs get worse?!?

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addyguy

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This is something I've been noticing for a while, and I just don't understand it, and its driving me nuts!

We can all agree that with the advent of new API specs for oil, ie. SJ-SL-SM, that oil get 'better' - it last longer, keeps engines cleaner..etc. But one this I have noticed is that as this march forward is progressing, the cold-cranking specs of most oils are geeting much worse! I don't necessarily have the prooof for all these, but I do have enough examples to show a trend:

SL Pennzoil 5W-30= 4400cst @-30
SM Pennzoil 5W-30= 5800cst @-30

SL/SM Kendall GT-1 5W-30= 5300cst @-30
"Newest" SM Kendall GT-1= 6200cst @-30 (!)

SL Ultramar Synthetic 5W-30= 3700cst @-30
SM Ultramar Synthetic 5W-30= 4900cst @-30 (!)

SL/SM Valvoline AC 5W-30= 5000cst @-30
SM Valvoline 'Premium' 5W-30= 5531cst @-30

The reason I think for this change is that as oil manufacturers have to make oil that is tougher against volatility, they have to use slightly thicker basestocks, and reduce the 'spread' of the oil, while keeping it within the API guidelines.

I'm also aware that as basestocks and add packs get better, oils protect better, so have really low cold crank numbers isn't AS important. Finally, I'm also aware that the differences between a lot of these numbers is moot, and in most scenarios no-one can tell the difference between a '4400 cst oil' and a '5800 cst oil'.

But it still bugs me...seems like progress in the wrong way...any thoughts?

Roger
 
Originally Posted By: addyguy
The reason I think for this change is that as oil manufacturers have to make oil that is tougher against volatility, they have to use slightly thicker basestocks, and reduce the 'spread' of the oil, while keeping it within the API guidelines.


Bingo.
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Quote:
But it still bugs me...seems like progress in the wrong way...any thoughts?


There is always a "give and take" aspect to oil formulation, so no I do not see it as a backwards move.
 
Also, consider your definition of "Much worse"? 1000 centi-Stokes? How does that affect YOUR vehicle? My guess is you won't be able to tell the difference.
 
The difference between 5,000 cP and 5,500 cP isn't that meaningful; cold pumping specs vary much more and if anything, they've gotten better from the data sheets I've looked at. Valvoline has improved . SM/GF-4 really places on emphasis on maintaining cold weather performance through the life of the oil compared to SL/GF-3, so in the grand scheme of things, SM/GF-4 is likely still better.
 
Originally Posted By: mechtech2
Specs at -30 are for WAY extreme conditions.
What are the specs at 0 F or so? That is much more realistic.


Ha Ha Ha... You southerners are so funny! Talking about our day to day life as if it's an anomaly.
 
Originally Posted By: mechtech2
Specs at -30 are for WAY extreme conditions.
What are the specs at 0 F or so? That is much more realistic.


Choosing a winter oil by "normal" or "average" conditions is pretty darn foolish if you think about it.
wink.gif
 
addyguy -
Thanks for bringing this topic up again. It has also bothered me. Many of the oils that have raised their cP numbers at -30 C (-22 F) are fully synthetic 5W-30 oils. These oils are supposed to be thin at cold temperatures! They are supposed to be much better at cold cranking than dino 5W-30 oils, but they aren't.
Phillips 66 Blend 5W-30 has gone from 4500 to 5300 to 5900 cP.
Pennzoil Platinum 5W-30 from 4400 to 5100.
Valvoline HM Syth 5W-30 is 5800.
And one of the Quaker State full synth oils is 6100, for crying out loud.
Shell Rotella 5W-40 isn't much thicker @ -30 C - 6400 cP.
When I'm trying to start a car up in Northen Wisconsin at -35 F, I want thinner oils than these. What's thinner? Back in the day when Mobil still published cP figures for its M1 line, M1 5W-30 was 3600 cP @ -30 C. Now that's a pretty thin oil at brutal below zero temperatures. But these days only 0W-30 oils seem to be really thin @ -30 C. And 0W-30 oils are hard to find. I can't find 0W-30 M1 anywhere around here.
I'm getting off the soap box now.
 
Pennzoil Platinum 5W30 is 5100Cp but that is at -35°C (-31°F) not -30°C (-22°F)

Another thing that goes along with the rise in Cp is a rise in the pour point. PP 5W30's pour point is -39°C, it used to be something like -45°C.
 
Originally Posted By: sceva
Pennzoil Platinum 5W30 is 5100Cp but that is at -35°C (-31°F) not -30°C (-22°F)



This is true. But, that is good enough for me. I think thicker is better......
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Even some 0W30 synths are not much better. In Canada the popular Esso XD3 0W30 (full synth) is CCS 5900 cP @ -35C. It is not much worse than other 5W30 that were cited but not near as good as M1 used to be.

I noticed that specs are bit different based on target market. In Canada Shell sells a lot under its and Formula1 brand. Their regular dino 5W30 CCS is 5900 cP @-30C which is comparable to some blends and synths cited above. I think Formula1 has a similarly decent CCS spec.

I simply decided to mix in some lower weight 5W20 oil during winter months. For instance, Shell's dino 5W20 CCS is 4900 cP which is closer to what M1 used to offer. Below 0F engine temperature is lower anyway, so no danger of high temp breakdown.

My guess is that producing better CCS involves much higher costs while for most of North America temperatures are generally not that low, so they have been neglecting CCS to reduce production costs. Few companies that sell to the north (Canada) like Shell still care about CCS. Others don't. That is a pure speculation, of course
wink.gif
 
A 5W-30's CCS at -35C would be approximately twice what it is at -30C, so Esso at 5900 is significantly thinner than the aforementioned 5W-30s (at -35 at least).
 
sceva said:
Pennzoil Platinum 5W30 is 5100Cp but that is at -35°C (-31°F) not -30°C (-22°F)

You are correct - my mistake. Thanks for bringing it to my attention. But it's odd that Pennzoil and a few other oil companies use -35 C for a 5W oil cP spec. The API standard shows -30 C for 5W oils, which most 5W oils are specified at.
And if cfromc's rule of thunb mentioned above is roughly correct, Pennzoil Platinum would come in at about 3000 cP @ -30 C. I may have found my new favorite "thin" 5W-30.
Click to expand...
 
I'm pretty sure that Pennzoil Platinum PDS has a lot of typo's in it. Take a look, they rate the 5W-20, 5W-30, and the 10W-30 BOTH at THE SAME TEMPERATURE for the cold cranking AND the borderline pumping temperature! For the 5W's one is supposed to be at -30 (CCV) and one at -35 (MRV)......

EVEN with that straightened out, a 5150cst cold-crank for a 5W-30 SYNTHETIC doesn't impress me when 'el-cheapo ESSO Protect 5W-30 will do 5300cst at the same temperature!

OR, another comparison: W-M re-refined 'Supertech' 5W-30 is rated at 6200cst at -30 and is about $2.00 litre here in Canada....Kendall GT-1 SYNBLEND(!) 5W-30 has the exact same cst number...6200cst @30, and is $3.99/litre! Why would you pay $2.00 more for an oil that does the exact same ting in the cold!!!
 
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