Prove to me, the perceived benefits of synthetic!

[The Critic]

From reading this forum for the last few years, I gather that these are the most commonly agreed/perceived benefits of synthetic oils:

1) Improved low temperature flow
2) More resistant to oil breakdown at extreme oil temperatures (305F or higher)
3) Improved viscosity retention
4) More linear viscosity profile to benefit VVT systems, as some of these systems use engine oil as a hydraulic system
5) Improved film strength
6) Reduced engine deposit build-up
7) Increased service intervals

GM recommends synthetic oil in cold climates. They also factory fill several of their track ready models with synthetic oil to eliminate the need for an oil cooler, and improve engine protection (due to reduction in oil breakdown) at oil temperatures above 305F. Certain 3.6L VVT-equipped V6 engines and VVT equipped Northstar V8 engines also carry a synthetic oil recommendation as the VVT systems prefer the improved cold temperature properties of synthetic oil, especially the more linear viscosity profile overall. Hence, I’m in full agreement with benefits #1, #2, and #4 of synthetic oil.

Some synthetic oil users use the product for the purpose of improved viscosity retention and improved film strength. Yet, I do not see significantly improved UOA results resulting from the usage of synthetic oil, considering normal daily driving conditions. Thus, I’m skeptical of the claimed benefits #3 and #5 as justification of using synthetic oil.

Lastly, I come to the most common reasons why some use synthetic oil (when it isn’t recommended by the OEM): reduced engine deposits (#6) and increased service intervals (#7). Repeatedly, I’ve yet to see any solid evidence indicating the reduction of engine deposits by using synthetic oil, compared to using conventional oil changed at recommended intervals. Note: this only applies to applications where synthetic is not required. So, with all this talk about synthetic oil keeping your engine cleaner, prove it. I’m not convinced, yet…

In addition, why is the extended service interval capability automatically assumed when using synthetic oil??? From what I gather, engine oil is replaced for a variety of reasons: contamination, additive depletion, prolonged exposure to extremely high oil temperatures, etc. But why does the usage of synthetic oil allow one to go much longer between oil changes? Won’t synthetic oil be subject to the same level of contamination as other oils?

GM calibrates their oil life monitor with the same upper limit for vehicles equipped with or without synthetic oil. All SM/GF-4 rated oils have the same limits on the main additive treat levels. Some state that the higher starting TBN on synthetic oils allow for longer service intervals. But this is changing. Look at the new Amsoil 5w40. It is rated for 502.00/505.01 applications. The starting TBN is no higher than that of most conventional oils, if not lower. Yet, the recommended service interval for 502.00/505.01 applications can sometimes be in excess of 10k miles. Thus, perhaps TBN isn’t as hyped up as some claim it to be. And the many UOAs users do on this forum does not indicate the amount of active additive available.

My point is that I’m not fully convinced that synthetic oils provide some of its perceived benefits, especially to the average driver. I’m especially interested in what some of you have to say about synthetic oils and extended service intervals. I’m not convinced of some of the benefits synthetic oils claim to have. Now prove to me that synthetic oil can really last drastically longer, keep my engine significantly cleaner, that the improved film strength can significantly reduce engine wear under normal driving, and the improved viscosity retention can make a difference.

TIA.

 

[sootyoil]

using dino oil for years then using true synthetic oil was a easy change for me once I used the oil.
my torture test I used worked out well for long duration in a 370hp to the wheels ford I have.
I learned the value of true PAO synthetics and wont
be fooled by fake synthetic oils.
No drawbacks using the best available lubricants.

 

[elsmacko]

Wow you have over 2900 posts here; and you're asking us to prove that synthetic will help make your engine last longer? I don't even know what you are driving?

My car is turbocharged. Turbos are notoriously hard on engine oil, sometimes even at 3000 OCI you can still get coking with a dino oil.

But there are tons of info here already, and it depends on the application.

 

[james21]

Being a newbe here, I question the same thing. The uoa's sure don't show any benefit of synthetic. I read one uoa which showed better wear numbers with dino in the middle of winter. How could that be? Everybody says you need it for turbocharged engines also. Well, a had an 80 trans am with the 301 turbo and ran 10w30 castrol dino for years and the car ran like a top, mileage was over a 100k before the speedo broke, and drove it for another 4 years, without an issue. My current 4.7 ram is on a synthetic diet for fear of sludge, but even today I question if this is better than having regular oil in it with higher detergent additives in it. Over and over again uoa's show lower wear on dino oil, doesn't this tell us the whole picture? Isn't wear the number one issue we should be looking at? A great post, Mr Critic, the proof is in the uoa's!

 

[jorton]

You need replies from folks who've had a poor UOA report and then corrected an issue by switching to M1.

 

[BrianWC]

Quote:

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Being a newbe here, I question the same thing. The uoa's sure don't show any benefit of synthetic. I read one uoa which showed better wear numbers with dino in the middle of winter. How could that be? Everybody says you need it for turbocharged engines also. Well, a had an 80 trans am with the 301 turbo and ran 10w30 castrol dino for years and the car ran like a top, mileage was over a 100k before the speedo broke, and drove it for another 4 years, without an issue. My current 4.7 ram is on a synthetic diet for fear of sludge, but even today I question if this is better than having regular oil in it with higher detergent additives in it. Over and over again uoa's show lower wear on dino oil, doesn't this tell us the whole picture? Isn't wear the number one issue we should be looking at? A great post, Mr Critic, the proof is in the uoa's!

---

Try a search on here for saab sludge. The "dino or synth blend must be just as good" attitude got a lot of dealers in trouble.....

 

[92saturnsl2]

While the difference in engine wear between synthetic oil and conventional isn't nor will be definitive, I like the idea of doing the research, and simply having the best protection for my investment.

My truck was a 25,000$ investment that I've decided to keep for the long-run. Just assume for example I would like to drive this 300,000 miles, driving 20k per year. The cost difference for me in each oil change between both oils is roughly 12$ (2$ x 4qt for conventional, or 5$ x 4qt for synthetic). Using a 5k OCI (which is conservative for most modern synthetics), after doing the math, I'll pay 720$ extra in oil changes throughout the 300,000 miles, or 48$ per year at 20k miles per year.

I can think of many things I've wasted 48$ on in the course of a year that I would much rather put toward extending the life of my truck. Sure, weather or not synthetic is going to benefit a certain application is in question, what I do know is the truck is supercharged, run very hard, and has a small 4 qt sump. Synthetic it is.

 

[o2man98]

Why is it always "prove it" to The Critic?

 

[Tom NJ]

Hi Critic,

Good post. You do not appear to be denying the technical benefits of synthetics, or their need in certain engines or driving conditions, but rather questioning whether these advantages are meaningful, perceivable, and offer value to the average driver with the average engine under average driving conditions versus a mineral oil with 3K OCIs. That’s a valid question. And there are valid reasons.

The technical advantages you list for synthetics are directionally true. Synthetic base oils are considerably more stable at high temperatures than conventional base oils, and generally flow much better at low temperatures. Because they resist oxidation better, they also contribute less to varnish deposits, and if they contain polar base oils like esters will help clean engines and increase film strength. And the ability to allow lower viscosities without sacrificing volatility helps increase fuel efficiency. And because of the slower breakdown rate they can allow extended OCIs. BUT, to your point, do these directional benefits provide enough value to the average consumer to justify their higher price. That depends on what that average consumer wants.

First, there is a certain percentage of people who just plain want the very best for their car, and synthetics are that. Oil companies market multiple levels of oil quality, most having a fighting grade for the price shoppers, a mid-level oil such as a Group II+ or partial synthetic for the value shoppers, and “My Best” for the quality shoppers. Synthetics represent the “My Best” line and not only get a better base oil but a better additive system as well. If you are going to pop for the cost of the synthetic base oil anyhow, most companies will go all out to create a flagship oil that will demonstrate their best technology and allow reputation enhancing advertisements. This more robust additive system in synthetics is a valuable contributor to the oil’s benefits, especially extended OCIs, and is a key reason I use synthetics.

Second, not everyone likes to change their oil every 3,000 miles in all their cars. I am one of them and place great value on the reduced labor, cost, and hassle of lying under my car in the cold and scrubbing black oil out from under my fingernails. The stronger base oils and additive system of a good synthetic gives me sufficient comfort to change my oil once a year at 10K miles, and that more than anything is enough for me.

In addition, some people value the insurance factor of knowing that their oil can withstand extreme conditions and protect their engine if something goes wrong, such as overheating, cold snaps, or mechanical malfunctions. Other people may be driven by environmental concerns, and synthetics contribute to reduced fuel consumption and less oil to dispose of.

Engine durability and cleanliness are much harder to prove and probably not very meaningful for the average driver, but for those that really push their cars or intend to keep it for more than the “average” 100,000 miles, there is some comfort in the fact that synthetics can provide an extra measure of film strength through VI or polarity, whether or not visible on each UOA.

Fact is people use synthetics for different reasons, and it is more of a personal decision based on their individual perception of value than a generic measurable formula. I use synthetics because I hate oil changes, like saving fuel, value the insurance factor, and can afford it. Other “average” drivers may not have the same drivers as I do and will do fine with cheaper convention oils and frequent changes. But will they really save money?

If the average consumer uses four quarts of oil, drives 12,000 miles per year, and changes oil every 3,000 miles, they will buy 16 quarts of conventional oil per year, which at say $1.50/quart is $24 oil cost. To this let’s add the labor portion of an oil change at say $15, times four oil changes and we have $60 in labor for a total oil cost of $84/year.

If one uses a synthetic at $6/quart and doubles the OCI to 6,000 miles, the oil cost is 8 quarts times $6 or $48/year. Two oil changes instead of four reduces the labor cost to $30 for a total of $78/year. Now subtract the fuel savings of say 1% and we save another $10 to give a total oil cost of $68/year. And I am not counting the less tangible “savings” that could potentially arise from reduced engine wear, easier starting, less battery draw, and insurance from mechanical mishaps. And not to mention my time saved by reducing oil changes!

Of course we can argue these assumptions all day, but the point is that synthetics are not really as expensive as the price tag would suggest. It is not the price of the lubricant that matters, but the cost of lubrication!

So if the best oils with stronger base oils and more robust additive systems have a total cost of lubrication for the average driver about equal to lower quality oils, why not use the best?

Tom

 

[BrianWC]

Proved!

 

[Triple_Se7en]

If you plan on being first & last owner of your vehcicles, synthetics are a good investment. Changing the oil alot sooner than the OLM indicates is even smarter than moving into synthetics. Otherwise... you don't need synthetics for only 100K-type service - before selling your vehicle. Dino oils like Super-Tech & Citgo (hypothetical) .. will do just fine when changed every 4K - for the Average Joe who doesn't keep the original purchase vehicle very long.

 

[Trex101]

I have a customer who is running 20w50 mineral oil from dealership for the past 3 yr under warranty. This is what came out after a single run of Redline 10w30 (10k km OCI) engine oil. You will be surprise what cheapo dino will do to your engine in the long run.

 

[Oil Changer]

You NEED to use synthetics if you want to use an 0Wxx.

 

[Thatwouldbegreat]

I don't have to prove the benefits of synthetics... I believe top synthetics are good oil choices for my vehicles.

Oils, fuels, and engine design and quality have improved, so with new cars and trucks what matters is vehicle specific oil selection . I have no doubt that many GF-4/SM oils are quite good. [ except for motors that need more EP/ AW additives like certain older cars, or some modded engines ]

I still choose conventional oils for vehicles operated in high dust environments, since I believe in short OCI's when dust is a concern.

But when towing, or driving really hard, or running longer OCI's...I prefer synthetics like :

-Redline 5W-20, 5W-30, 5W-40, 10W-40,
-Castrol GC 0w-30,
-M1 0w-20, 5W-30 EP, 0W-40,
-Delvac 1,
-LubroMoly 5W-40.

I also think its time to stop thinking in terms of synthetic vs conventional oil. All oils are compromises, and there is no one oil that works best for all applications.

Although Redline, GC, M1, Delvac 1, and Amsoil are my faves.

The discussion should realy focus on matching a given oil to a specific engine and usage, maintenance goal, and operating environment.

Right now I'm trying to figure what tranny and gear lubes and service intervals I should use in my 2005 Silverado 2500HD Crew Cab Duramax/ Allison.

The Allison tranny has Dexron III and it may be best for warranty purposes, but Allison Tech prefers Castrol Transynd. And Dexron VI may be a good compromise.

The front diff has mineral oil, and the rear diff has $28 /qt GM synthetic. While the transfer case has a special AllTrac II fluid that may have no equal.

I may decide to drain all boxes at 20K and use Dexron VI, Amsoil SVG or Redline 75W-90 in the front and rear diffs, and stick with AllTrac II in the transfer case.

I don't care about conventional vs synthetic... I want to look at what's best overall for the vehicle and the warranty.

So its nice to discuss and get feedback from other enthusiasts and the resident experts.

This is what BITOG does best!

 

[toocrazy2yoo]

 

[ewetho]

20W-50 to 10W-30 just flow rate increases could dislodge some stuff. There are plenty of cars that have gone 200,000 to 300,000 mile on oils such as Havoline, Castrol, Pennzoil, Valvoline on regular oil changes that were essentially clean. The question still stands. Think about it even on big rigs if you use synthetics in your gears you get a longer warranty. In your engine no change. If you race or have an engine that is very hot (HP/in³) use synthetics. Got a corvette that has no oil cooler and needs one then use Synthetic. If you have low HP grocery getter with no turbo than the new GF4/SM oils will do fine at normal intervals.

Are synthetics better. Yes of course at everything above. If your engine does not push the oil past the design specs of GF-4 for wear protection will you see a difference ????? Not likely that is why after UOA after UOA you do not see an appreciable difference in wear. So the SAAB you say. Well could it be they did not spec an oil requirement that the car demands, sounds like it. They spec regular oil and then push the oil beyond its limits that is a problem and probably corrected by Synthetic oil. So in their case upgrade to what your car needs.

My car seems fine either way as while I believe the oil will stand up to more I change early. Drive me nuts some how. Guys go 200,00+ on Walmart Dino all the time yet no real difference when on synthetic. Go racing were it will spend all day at 5-7K RPM and then we need to talk. Pull out your favorite synthetic.

 

[1sttruck]

One example is to look at tougher requirements that SM and/or GF4. Looking at A5/B5 oils at Wally Workd for instance I'v only found two; M1 10W30 EP and a Castrol synthetic. Another example is looking at Ford's requirements, where the Motorcraft (all others too ?) 5W20 is a synthetic blend - why didn't they use all dino ?

The benefits of synthetics are real, but if your vehicle and/or driving style don't benefit from the benefits then don't use them.

 

[Thatwouldbegreat]

I agree with you ewetho for the most part.

Some normally aspirated engines like Subaru H-4, or Honda 4 cylinders can make 300K with conventional oil at 3K to 5K OCI's. Some engines are just good or lucky designs that are easy on oil and have few weaknesses.

Other engines may have problems after 100K due to weak ring packs, large internal temperature differentials or hot spots, or something that shears, evaporates, or oxidizes oils.

Some of these less than perfect motors may have only a few examples that reach 300K and many will fail earlier.

If the owner had chosen synthetic oil it might make the difference in service life. And the owner may not know if a newer engine design is good or bad, easy or hard on oil until a few years and many tens of thousands of miles.

So in an argument like this; synthetic oil may be a safe bet until there is more shared knowledge on a motor...or tranny, or differential.

I have lots of cars with engines designs that have built up a good reputation like the Mercedes Diesel I-5, BMW I-6, Subaru H-4 NA [ head gaskets excluded ], Porsche H-6 NA, and Honda I-4....and still I use synthetics in nearly all of them. [ The Mercedes gets Hydrocracked Delo 400. ]

So if my argument makes sense then upgraded fluids might be a safe bet until operating experience helps to identify the minimal safe oil.

I'd hate to have followed the owner's manual advice and then get a TSB that I should have used a better fluid, or be one of the unfortunate victims of a dealership that didn't use the right oil. This happened with Saab and Mercedes owners. Toyota and Saturn owners, and probably many other car owners had lots of engine problems that might have been avoided if the owner had used better oils or different intervals.

 

[deven]

http://63.240.161.99/motoroil/103.html
http://63.240.161.99/motoroil/104.html

 

[Bill in Utah]

Quote:

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You will be surprise what cheapo dino will do to your engine in the long run.

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Yeah, I guess 300k miles in one engine, 200k+ on many motors and always 120k+ on every motor using whatever is on sale (Havoline, Valvoline, Qs Pennzoil and Castrol GTX) has shown how damaging conventional oil is...

And thats over 30+ years with oil standards that were not as good as today.

Sorry, going to say your wrong on this one.

Remember there are people looking for FACTS on motor oil.

If you change the oil at the recommended OCI and use what they say in the manual, your engine is well protected and will last a long long time.

If you race, have a force fed engine or the manual states Syn, go for it.

BUT, if you think your going to get a longer life using Syn and changing it every 3-5k because its "better"

, your wasting $$ and not doing anything but the oil companies bottom line any good.

Oh, and anyone who thinks that Syn will "protect" your engine on a overheat, you need to do one thing.

SHUT the engine down before it overheats. NO OIL will help you.

Take care, Bill