Is Syn 10W-30 Almost Eqv. to SAE30?

[Nickdfresh]

I've mentioned this a few times and recall it being said here. But I'd like to hear some comments regarding if a synthetic 10W-30 with minimal or no VII's is roughly equivalent to a conventional SAE30 at most temps.

Is this still true with the shift to Group III oils and GTL base-stocks? Is it only true for syn oils that are mostly PAO/POE? Obviously this has the biggest implication regarding power equipment like mowers and some snowblowers...

I did do some searching and came up with Craig from Canada's comments which seemed rather informed:

This Thread https://bobistheoilguy.com/forums/ubbthreads.php/topics/1095089/Re:_Advantages_of_using_SAE_30

 

[AirgunSavant]

As a kid I was in charge of our then new 1972 Wheel Horse 12hp tractor which I still have today.
It was delivered with W30 as new and I used 10w30 all the way up until this year. It has the old original ball bearing Kohler engine and has never been rebuilt. Yes it has had three mower decks and some other goodies but the engine still runs fine. And that mower was used hard and as a go kart as well. All oil was conventional- no specific brand either.

 

[4WD]

I use the M1 10w-30 HM pictured - was looking at Mobil spec sheets one day & the numbers looked good as does the price ...

 

[Kuato]

Interesting you used the Amsoil picture...your answer in for that oil is Yes -- it was originally formulated as a 30 weight oil, but was so good it met the requirements for 10w30 and was labelled that way.

I have no knowledge of the other ones so I can't speak for them, but it's certainly possible.

 

[Shannow]

http://certifieddef.com/media/wysiwyg/Mobile/Mobile_High_Mileage_10W-40.pdf

The Mobil PDS has a VI of 149, and an HTHS of 3.5.

Calculating out the "KV150", and correcting for density (CSt to Cp), there's a bit of VII action in that oil.

 

[userfriendly]

I calculated a couple of KV100C 12.0 mono-grade group IIs, density .890 and the HTHS was a couple 10th's higher @ 3.7
But, they would be 20W30s. Chevron's 15W30 must be a synthetic blend to pass 15W, and have a HTHS of 3.70.
The price you pay to have a multi-grade is a hit on the HTHS vs KV100C.

 

[BrocLuno]

Redline rates their racing oils as straight grades (mostly for racers who do not care about "cold start" issues). But, they also rate them as multi's for the street crowd that do care. They are largely PAO based synthetics. So, yes, in that case a 10W-30 and 30 HD are the same...

As stated above, I think Chevrons 15W-30 SD (severe duty) is as close as possible to the multi/ mono ratings using Group III (?).

 

[Nickdfresh]

I was under the impression that Redline's "racing" stuff was largely a POE/POA blend, at least at one time. Their street oils were probably POA based AFAIK...

 

[Dufus2]

In the past, I used Amsoil Diesel Oil SAE 30 and the cold start was comparable to a dino 10w30
My lab tests had reduced wear metals with a 30w as compared to 10w30 and 0w30 (Amsoil products that cost more). It leads me to believe that single grade oils protect better in real world testing even if the auto industry says multi-grade oil is better... I still run 30w all summer, even if its the stuff from Walmart.

 

[andyd]

D2, Up until recently, 30w was the standard oil to best accommodate the tolerances the parts conformed to. Now that robots build to tighter tolerances, thinner oil can be used? Thats a total wild @$$ guess. 30 w oil was used in everything including 2 stroke mix.

To the PO's question.Synthetic Multi-viscosity oils tend to empty your wallet faster than dino which also shears more readily than single viscosity oils. Just make sure that there is some oil in the engine. The rest is interweb science. That is the bottom line. Doesn't really matter what you choose. It is all good. Just keep the oil high on the stick.

 

[901Memphis]

Regardless of the reasons behind it Mobil 1 10w30 was AMAZING for any 10w30 or SAE 30 small engine when it was API SL, I don't know about that anymore since marketing made it API SN, but I'm sure it's a good choice still, the little air cooled engines like the less volatile base oils in the synthetics more than anything since they get so hot, the premium additives used in most synthetics is just icing on the cake.

I would use Pennzoil synthetic 10w30 first if I could find it. Most likely all GTL and no VII

 

[Merkava_4]

Originally Posted By: Kuato
Interesting you used the Amsoil picture...your answer in for that oil is Yes -- it was originally formulated as a 30 weight oil, but was so good it met the requirements for 10w30 and was labelled that way.


So does that mean that Amsoil 10W-30 and its sibling SAE 30 are the same oil in different bottles ?

 

[Kuato]

Possibly...I don't know for sure, but Pablo likely does.

 

[Shannow]

Looking at the data sheets, they aren't close enough to be the same.

 

[Pablo]

Originally Posted By: Kuato
Possibly...I don't know for sure, but Pablo likely does.


The oil pictured is ASL. It is not the same as ACD or ASE. Different base oil composition on up. Now ACD and ASE, I think we can say for certain the base oils are the same. But the additives quite different.

 

[Kuato]

Thought there would have been more discussion on this thread...

 

[SR5]

This 5W30 thread ended up talking about blending straight PAO monogrades as narrow range multigrades.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4248186/

 

[wgtoys]

Another way to ask your question is: Do (some at least) 10W-30 rated Synthetic motor oils achieve their viscosity stability over temperature primarily due to the quality of the base stock(s) without using specific viscosity index improvement (VII) additives to achieve the required viscosity vs. temperature performance needed for both the "10W" and "30" aspect of their specification?

Have a look at this chart: http://media.noria.com/sites/archive_images/Backup_200203_LubSelecTab2&3.gif

Most 10W-30 oils have a viscosity index of 135-150 which is greater than the 124 shown above for a group III or IV base stock.

This implies that most 10W-30 oils, synthetic base or not, likely use some amount of Viscosity Index Improver additives to get the job done.