What is better? PAO Only or Pao/Ester Oil?

Messages
65
Location
Dallas, TX, USA
Thread starter
I always thought that PAO, far outperformed, outlasted and remained in-grade better and more reliably than the "other" synthetic (or synthetic wanna-be). Now, I've run across both, and was wondering which was the "better" oil. I am basically comparing 0W30 (German Castrol)which is PAO and, Total Quartz Energy 9000, 0W30 which is the old Elf Excellium Full-Tech which is a PAO/Ester rich oil.They both meet all the same specs. I am just trying to understand the PAO (vs) PAO/Ester (vs) Ester based oils as well as the pro's and con's of either.
 
Messages
4,574
Location
Merritt Island FL, USA
You could write a doctoral dissertation on the properties of PAO and Esters...especially esters which have fall under such a diverse category ie Grp. V. I can say there is a lot of info at your finger tips on BITOG to find the differences. I can give a quick summary (to the best of my knowledge) Ability to withstand heat/oxidation. PAO:Good Ester:Good-Excellent Hydrolytic stability. ie.water absorbs into the oil. PAO:Excellent Ester:Poor Additive solubility. PAO:Poor Ester Excellent Seal Swell. PAO: Poor Ester: Excellent Vis. PAO: Excellent Ester:Excellent Film Strength, PAO: Good Ester: Good Lubes N' Greases Oct. 2010 Pg.44-45 As you see they have their pros and cons. A mix is obviously better. Additive solubility is very important, Esters shine in this category.
 
Messages
314
Location
Orange County, CA
Hi. Simply from a chemistry standpoint, PAO + Ester > PAO only. Why? Because PAO will break down/not stable at higher temperatures in comparison to ester. However, PAO maintains high compatibility with mineral oils. When you combine the high temperature stability of ester and PAO, you can possibly get a better oil. I say possibly because in science, there are no absolutes in the real world. Most "full synthetics" are PAO only. Why? It is more affordable to produce and offers most of the advantages that people are thinking about when they think about synthetic oils. Only a handful of companies produce an ester + PAO combination. Ester only oils are not exactly a solution either because they have problems with compatibility. If someone is marketing an ester-only fully synthetic oil as being better than other types of synthetic, I would be wary. Ask for an in-depth explanation as to why it is beneficial over a PAO or PAO + ester oil. But the most significant problem is compatibility with conventional oils. This is a common situation with automobiles today, and is significant, which is why I am highlighting it. Another significant problem is that ester gets saturated with water easily and becomes unstable. Otherwise, if you don't care for compatibility then by all means an ester is a high quality choice. PAO are simply highly refined mineral base stocks. Under the definition of synthetic, it's marketed as such because it is manipulated in the lab. Otherwise, olefins come from the ground from dead dinosaurs. Synthetic oils are 90% this kind. Highly refined petroleum base stocks. If you want to see the similarity, compare the Viscosity Index of a SM/SN grade conventional oil and a synthetic. They are remarkably similar. Honestly, your engine won't care if the VI is 170 or 180. Ester does not come from petroleum.
 
Last edited:
Messages
1,877
Location
Pacnw
Messages
314
Location
Orange County, CA
Oh and I also have something to add. Ester-based oils come straight from racing. Racing involves less environmental conditions than the everyday roads we drive. So the demands are different. What may be "better" can be better under the checkered flag...but not necessarily under a stoplight. It's all about finding the right mix to fit the conditions encountered. Now, if any oil meets API standards and OEM specifications, it is ok for your engine. Likely to see significant differences between chemical composition? Highly unlikely to the consumer.
 
Messages
1,877
Location
Pacnw
Originally Posted By: dtt004
Another significant problem is that ester gets saturated with water easily and becomes unstable.
This is incorrect when it comes to motor oil. Please see my above post or feel free to search and find the previous discussions on it.
 
Messages
314
Location
Orange County, CA
Originally Posted By: saaber1
Originally Posted By: chubbs1
Hydrolytic stability. ie.water absorbs into the oil. PAO:Excellent Ester:Poor
Esters in motor oil have zero issues with hyrdrolytic stability. This has been debunked on BITOG at least 3 times if not more: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2017391 Also fyi a great paper by Tom NJ, BITOG's expert on esters: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1252272
Good point. However, I think he was talking about the simple chemistry. Just because it has been debunked in the automobile, doesn't mean it's debunked in chemistry. Esters simply are hydrolytically unstable in comparison to olefins. Anyways, great point.
 
Messages
18,449
Location
East of IGO
There must have been a whole lot of dinosaurs to make all the oil that has been pumped out of the earth the last 100 or so years. I thought ester based oil came out of aviation?
 
Messages
1,415
Location
Alaska
I wish we'd all get past the "dinosaur" thing. Dinosaurs have nothing to do with petroleum. It comes from anaerobic breakdown of monocellular organisms like prokaryotic bacteria and eukaryotic dinoflagellates; underwater, usually if not always sea water. Coal at least has markers of real plants in its' makeup; closer to dinosaurs but still no banana. And obviously all the carbon atoms in PAOs and esters originally come from "mineral" sources: petroleum, gas and coal. Charlie
 
Messages
11,810
Location
PA
Originally Posted By: BritGerCarLuvr
I always thought that PAO, far outperformed, outlasted and remained in-grade better and more reliably than the "other" synthetic (or synthetic wanna-be). Now, I've run across both, and was wondering which was the "better" oil. I am basically comparing 0W30 (German Castrol)which is PAO and, Total Quartz Energy 9000, 0W30 which is the old Elf Excellium Full-Tech which is a PAO/Ester rich oil.They both meet all the same specs. I am just trying to understand the PAO (vs) PAO/Ester (vs) Ester based oils as well as the pro's and con's of either.
First, German Castrol isn't 100% PAO. One of its most important components is an ester; it's just present in small amounts. Second, regardless of the individual advantages and disadvantages, it's the total formulation that counts. Knowing whether an oil contains PAOs and/or esters is like knowing whether a car is supercharged or turbocharged. In the end, that fact in isolation tells you almost nothing about how the product actually performs. Modern oils are highly sophisticated mixtures that are more than the sums of their parts, and they perform differently in different applications. You could have a PAO oil that outperforms a PAO/ester blend, or you could have it the other way around; then you could take both oils to a different car and the order might switch. Theoretically you could tell a lot about an oil's performance from its composition, but this requires vastly more details than simple PAO or ester content (which are usually proprietary) and the necessary chemical and tribological background to interpret that information. This is one reason why it's much better to rely on approvals and specs. A PAO or ester oil might work very well in your car, or it might work very poorly. An oil that carries the correct approvals and specs is virtually guaranteed to work well.
 
Messages
70
Location
FL, USA
Don't suppose anyone has the HTHS for the energy 9000 0w30 oil do they? I've tried to ask Total directly and have got no response at all.
 
Last edited:
Messages
70
Location
FL, USA
Is it the ACEA A3 that tells us that? i.e. to meet ACEA A3 spec it's HTHS must be at least 3.5? It also seems to have a low BN (tbn?) compared to other oils according to the product data sheet. I think it's around 8. Could anyone suggest why this might be, and if it could be considered a disadvantage?
 
Last edited:
Messages
11,810
Location
PA
Originally Posted By: wolfestone
Is it the ACEA A3 that tells us that? i.e. to meet ACEA A3 spec it's HTHS must be at least 3.5?
Yes. Any spec that depends on ACEA A3, like LL-01, tells the same story.
Originally Posted By: wolfestone
It also seems to have a low BN (tbn?) compared to other oils according to the product data sheet. I think it's around 8. Could anyone suggest why this might be, and if it could be considered a disadvantage?
It doesn't really mean anything on its own. Maybe the oil's TBN retention is really good, so it doesn't need a higher number. Can't really tell without a lot more info, most of it propriety or only available through experiment.
 
Messages
10,146
Location
Burlington, Ontario, Canada
Originally Posted By: dtt004
PAO are simply highly refined mineral base stocks. Under the definition of synthetic, it's marketed as such because it is manipulated in the lab. Otherwise, olefins come from the ground from dead dinosaurs. Synthetic oils are 90% this kind. Highly refined petroleum base stocks. If you want to see the similarity, compare the Viscosity Index of a SM/SN grade conventional oil and a synthetic. They are remarkably similar. Honestly, your engine won't care if the VI is 170 or 180. Ester does not come from petroleum.
GP III oils are highly refined mineral oils. PAO's are are hydrocarbons but are usually synthesized from a gas such as ethylene. High VI oils are the "holy grail" of modern engine oils which is why they are the FF of most German and Japanese cars. Your engine will definitely know the difference between a 170 and 180 VI oil on start-up. At room temperature the 180 VI oil will be almost 10% lighter and 15% lighter at 0C. The FF of ever Porsche is M1 0W-40 with it's VI of 185. GC 0W-30 is no longer on Porsche's spec' list which is not surprising with it's VI of only 167. What that means, is M1 0W-40 despite being a 40wt oil is actually lighter than GC at temp's below 25C and at 0C more than 25% lighter. A 25% lower viscosity oil will flow about 2.5 times faster. An even more extreme everyday example is the Toyota 0W-20 (VI 214)which is the spec' oil of most Toyota's and Lexus model's now. A typical 5W-20 dino and some syn's has a VI of only about 150. That means the Toyota oil is a full 35% lighter at room temperature and a whopping 50% at 0C.
 
Messages
89
Location
Houston
Esters are usually found in PAO based synthetics as it helps keep the additives in suspension. Back in the early days of Mobil 1 it suffered from additive drop out if it sat too long.
 
Last edited:
Messages
65
Location
Dallas, TX, USA
Thread starter
Thank You for your reply. Am I to understand from your post, that M1 0W40 actually "flows" faster from a cold start than GC 0W30, yet affords the protection of a 40 weight oil at temp? On the other hand, what if just about all the oils recomended by the manufacturer are *W30 in nature, is a *W40 detrimental?
 
Messages
2,435
Location
Mizzou-land
I want to elaborate on what d00df00d has already said in response to the posts by dtt004. There are no PAO only, formulated motor oils. PAO is not highly refined mineral oil. PAO is not the most commonly found "synthetic" in the US market. Synthetics are not incompatible with mineral oils. Esters did not originate with racing. The earth is not flat and the moon is not made of cheese.
 
Top