Full SAPS Vs Ester??

Joined
Jul 1, 2019
Messages
8
Location
Suffolk
Interesting question or not, I'm not too sure??

So the factory recommended motorcycle oils now are very frequently ester based, they are also significantly lower SAPS content than older oils due to the fact modern bikes have catalytic converters fitted.

One can only assume that ester has been used partially to improve lubricity, perhaps to compensate for the reduction of SAPS required to not poison a catalytic converter?

If this is true, how might a low/mid SAPS ester oil compare to a full SAPS traditional 'fully synthetic' oil?
 
Joined
Dec 26, 2005
Messages
23,751
Location
Upper Midwest
I don’t understand the question, the “SAPS” level of the oil is not directly related to the base stock composition. You can have a low-SAPS ester based oil just as you could have one with a moderate or high SAPS level.
 
Joined
Feb 27, 2009
Messages
8,091
Location
down in the park
The ester base is more commonly used because the low saps level means the oxidation resistance of the add pack is lower. Typically the base oil quality needs to go up when there's less additives in the finished product, if you want to keep the same longevity/performance.
 

MolaKule

Staff member
Joined
Jun 5, 2002
Messages
23,076
Location
Iowegia - USA
The ester base is more commonly used because the low saps level means the oxidation resistance of the add pack is lower. Typically the base oil quality needs to go up when there's less additives in the finished product, if you want to keep the same longevity/performance.
The ester base is more commonly used because the low saps level means the oxidation resistance of the add pack is lower.

You mean if I use a higher percentage of ester in my formulation I am going to reduce my anti-oxidant chemistry? Please explain why I would do that?

Typically the base oil quality needs to go up when there's less additives in the finished product, if you want to keep the same longevity/performance.

If I formulate a motorcycle or even a boutique oil, why would I use less additives?? Please explain.
 
Last edited:

SR5

Joined
Jul 7, 2015
Messages
6,618
Location
Down Under
I assumed a high quality motorcycle oil used PAO and ester base stock because in general you want a motorcycle oil to be thicker (higher viscosity) and you want it to be shear stable.

Group I and II can be thick, but have lower oxidation stability and lower natural VI (Viscosity Index).

Group III and GTL synthetics only come as thin (low viscosity) base stock I believe. Requiring a thick version to be full of VII (viscosity index improvers) and therefore more prone to shear.

That leaves thick PAO with ester, as a high quality base stock that can both be thick for a low polymer VII load and also have good oxidation and heat stability, with a decent natural VI.

The SAPS level I consider independent of the above, and more related to the amount of ZDDP added for wear protection and the amount of metallic base detergents added for TBN to fight acid buildup. Given low sulphur fuel, and most motorcycle riders don't do long oil change intervals like you see in some cars and trucks, then you could reduce the TBN & SAPS level a bit. Same if you replace some of the ZDDP with different organic anti-wear additives.
 
Last edited:
Joined
Aug 25, 2018
Messages
3,087
Location
South Carolina
I assumed a high quality motorcycle oil used PAO and ester base stock because in general you want a motorcycle oil to be thicker (higher viscosity) and you want it to be shear stable...

Group III and GTL synthetics only come as thin (low viscosity) base stock I believe. Requiring a thick version to be full of VII and therefore more prone to shear.

That leaves thick PAO with ester, as a high quality base stock that can both be thick for a low polymer VII (viscosity index improvers) load and also have good oxidation and heat stability, with a decent natural VI.

Not necessarily. Consider the viscosity of the additive package also. Add packs tend to be very thick with a KV100 of 150-200 cSt. You can formulate an oil that's 60% Yubase 8 and 20% PAO 10 (as a VII) and 20% add pack that would make a 10W-40 with a KV100 of 13.3-13.7 cSt and pretty shear stable. In fact, group III/III+ base oils can produce higher HTHS ratings than PAO in some cases.
 
  • Like
Reactions: SR5

MolaKule

Staff member
Joined
Jun 5, 2002
Messages
23,076
Location
Iowegia - USA
is he talking about boutique oils? or am I? please explain?
I am asking you to explain yourself.

The ester base is more commonly used because the low saps level means the oxidation resistance of the add pack is lower.

You mean if I use a higher percentage of ester in my formulation I am going to reduce my anti-oxidant chemistry? Please explain why I would do that?

Typically the base oil quality needs to go up when there's less additives in the finished product, if you want to keep the same longevity/performance.

If I formulate a motorcycle oil or a boutique oil with Group IV of V base oils, why would I use less additives?? Please explain.
 
Joined
Dec 9, 2011
Messages
1,954
Location
Ca USA
What is 100% true for all the synthetics are uniform sized molecules
that don't exists naturally... no matter what brand of uniform molecules
we choose they will meet or exceed our mileage expectations...

full-45634-35374-synthetic_vs_mineraloil7.jpg
 
Joined
Dec 26, 2005
Messages
23,751
Location
Upper Midwest
What is 100% true for all the synthetics are uniform sized molecules
that don't exists naturally... no matter what brand of uniform molecules

full-45634-35374-synthetic_vs_mineraloil7.jpg
I guess I didn’t really see the problem with that little load diagram. Random sized particles are better at load distribution than uniform ones.

Other than it’s inaccurate and largely irrelevant of course. You say they don’t exist naturally but the little secret is they don’t exist synthetically either.
 
Joined
Jul 12, 2012
Messages
7,362
Location
Caldwell Idaho
What is 100% true for all the synthetics are uniform sized molecules
that don't exists naturally... no matter what brand of uniform molecules
we choose they will meet or exceed our mileage expectations...

full-45634-35374-synthetic_vs_mineraloil7.jpg
Is this valid with the current Hydroisomerized [Chevron trademark] base stocks ? I have always seen this as marketing hype and I first started using syn oil in my first motor cycle after about 6 months of ownership with great results in my first M/C a a Yamaha 125 AS1C 125. Steen C chemicle lube !
 
Last edited:

Motopsycho87

Thread starter
Joined
Jul 1, 2019
Messages
8
Location
Suffolk
I think this has gotten side tracked a little bit. Aware that esters are better than fully synthetic.

But what I'm asking is, it appears low SAPS oils have been improved to esters to compensate for this, perhaps? So how would a full SAPS older synthetic fare against an ester based lower SAPS oil?
 
Joined
Dec 26, 2005
Messages
23,751
Location
Upper Midwest
I think this has gotten side tracked a little bit. Aware that esters are better than fully synthetic.

But what I'm asking is, it appears low SAPS oils have been improved to esters to compensate for this, perhaps? So how would a full SAPS older synthetic fare against an ester based lower SAPS oil?
That still doesn't make a lot of sense, what does "low SAPS oils have been improved to esters to compensate for this" mean? And you say that it appears so, where have you seen this appearance?

Partial ester base stocks impart certain properties to a finished oil but you're on the wrong track with the whole SAPS thing. Have you read and understood what MolaKule wrote above? Where are you getting the notion that just because the base stock may contain some ester content the SAPS level is somehow lower? Do you know what SAPS stands for?
 

Motopsycho87

Thread starter
Joined
Jul 1, 2019
Messages
8
Location
Suffolk
That still doesn't make a lot of sense, what does "low SAPS oils have been improved to esters to compensate for this" mean? And you say that it appears so, where have you seen this appearance?

Partial ester base stocks impart certain properties to a finished oil but you're on the wrong track with the whole SAPS thing. Have you read and understood what MolaKule wrote above? Where are you getting the notion that just because the base stock may contain some ester content the SAPS level is somehow lower? Do you know what SAPS stands for?
New oils need to be low SAPS to work with catalytic converters, compatibility is stated on almost all datasheets of high performance ester oils.
 
Joined
Jan 30, 2018
Messages
566
Location
Northeast Texas
There aren't any gasoline or diesel engine specs or approvals that are being met by supplanting PE/POE into the blend for reduced SAPS levels.
If it is included, it is for alternative reasons.
 

ZeeOSix

$100 site donor 2022
Joined
Jul 22, 2010
Messages
35,170
Location
PNW
New oils need to be low SAPS to work with catalytic converters, compatibility is stated on almost all datasheets of high performance ester oils.
My 2016 Yamaha XSR900 has a catalytic converter. All Yamaha specs for the motor oil is: API SG or higher and JASO MA.

API SG is pretty old and probably different in SAPS formulation than the newer oils. What was the first API rating that went into effect to keep catalytic converters from going bad?
 
Top