Synthetic Oil

[RubHer Yellow Ducky]

I found this info and thought I would pass it on ...

Traditional wisdom tells us that a synthetic creation is usually not quite as good as the original it strives to emulate. (The difference between clothing made of polyester versus silk comes to mind.) Does that same truism apply to synthetic oil, when compared to automotive oil derived from crude?

Fundamentals
To grasp this slippery subject, we first need to cover some fundamentals. Synthetic oils are a result of scientific manipulation of non-conventional fluids, but here the silk-or-polyester analogy stops. Synthetic oils are definitely not the equivalent of polyester leisure suits; in fact, they are generally priced three to four times that of conventional oil. And, more to the point, synthetics are an improvement over their conventional kin.

Let's break down the details of synthetics, and what makes them better. One definition of "synthetic" is big molecules built up from small ones. Like genetic engineers, the oil companies figured they could improve the performance of engine oil and eliminate some of the shortcomings in the laboratory.

In the simplest terms, the base stock of synthetics, polyalphaolefin (PAO) starts as ethylene gas, a simple two-carbon molecule that is built up to a 10-carbon molecule. Three of these super molecules are combined to form PAO, a base stock that offers a number of advantages over Mother Nature's version. Synthetics are more stable, flow at lower temperatures, are more resistant to boiling off, and less susceptible to oxidation, which causes thickening with prolonged high temperatures.The inherent element with crude stock for motor oil is the molecular construction. Conventional motor oil is a batch of short-chain and long-chair carbon and hydrogen atoms. In extreme heat, the short chains can evaporate and these unstable molecules oxidize and break down. In addition, contaminants and reactive and/or unstable hydrocarbons can sneak through the refining process.

What's It Worth?
Are synthetics worth the extra cost? Universally, the answer is yes, whether for a high-revving turbo motor or an older engine that gets little use. Using another vivid comparison, French champagne is also worth the extra expense over sparkling wine, but it comes down to matters of your taste and bank account. Note, too, that most auto manufacturers do not specify synthetics, so unless you're one of the few who need synthetic oil, rest assured that you're doing no harm with good old-fashioned crude as long as you follow the owner's manual recommendations on viscosity and grade.

On the other hand, synthetics are better on a number of levels. They keep the engine cleaner through improved sludge and varnish protection, reduce engine wear at high temperatures with more stable viscosity, protect the engine when it's running under severe conditions at high temperatures, provide better cold-temperature starts with faster oil flow at ignition and improve fuel efficiency.

Myths
As with any new technology, there are a number of myths and advertising claims that need to be explored. Back in the late 1990s, the National Advertising Division (NAD) of the Council of Better Business Bureaus ruled that "synthetic" could be defined as the product of an intended chemical reaction.

As a result of this battle of semantics, the NAD, the Society of Automotive Engineers and the American Petroleum Institute ended up with broad interpretations of "synthetic." What that means to the layperson is this: if you want full synthetic or semi-synthetic or whatever, read the label to make sure you're getting what you want and what you think you're paying for.

One urban myth surrounding synthetic oil is its compatibility with conventional oil. At one time, those who switched from conventional to synthetics had to stick with synthetics?there was no going back. Synthetics expanded the seals in the engine; then, when conventional motor oil was used, that engine sprang multiple leaks.

Usage
Now, while the companies don't recommend mixing or switching back and forth, one company's synthetics are fully compatible with others and compatible with conventional oils. The source of compatibility problems was high levels of ester in the earlier synthetics. Considering the consequences, it's best to verify this compatibility, either on the company's website or with your trusted mechanic.

Next, oil changes. The PAO base stock does hold up longer than petroleum-based oils, but the additives in both wear out at the same rate. The oil companies have tested their synthetics for longevity, but they still recommend following the specific owner's manual for oil change intervals.

As for special oil filters or special disposal techniques for those who change their own oil, that's easy. You can use the same filter and follow the same disposal procedures that you would with conventional oils.

So, should you bite the bullet and fork over more money for synthetics? Sure, if you want to. If you are in a fully committed relationship with the car of your dreams, and have decided that car is worth the cost, spring for that Dom Perignon.

RYD

[MALADJUSTED]

Great info, thanks!

[f5fstop]

Good article, but missing some facts.
Many of the additives used in modern dyno oils over the past few years are a lot better than used in the past; thus, the modern "Starburst" symbol dyno oil last longer and is more stable than oil used even five years ago. Unless the engine is of a race design, or has limited airflow to help cool it, dyno oil is all that is required. GM (and all other manufacturers) recommend the oils that they test the engines with during development.

Synthetic will not harm the engine, but in many cases, it is not necessary. Extreme hot conditions and extreme cold conditions will see some benefit, but then again, the GM oil life system, which monitors temps at startup and during engine run, will take this into consideration. Therefore, those who live in AZ will see their oil life percentage decrease faster than those living in MI during the summer. Same holds true to those up in Alaska. Those living in moderate temp areas, with four seasons, will also notice that during the summer their oil life percentage will not decrease as fast as during a cold winter.

You will also notice a difference with your driving habits. Change the oil and go cross country and your oil life percentage will drop slowly. Change your oil and make a hundred one-mile trips to Kroger a mile away, and your oil life percentage will decrease faster.

In addition, there are two primary type of synthetics; Group IV synthetics are made with PAOs, group III are highly refined dyno oil via a process called Hydro-cracking, that is labeled synthetic oil, and is legal to do so. (Mobil sued to have the name synthetic removed from Group III oils back in the late 90's and lost.) Hydro-cracking is less expensive than using PAOs. To be honest, the inroads in the development of Group III oil have made them almost as good as Group IV. There was supposed to be a Group III+ category, but not sure if it has been released.

Last tests I saw showed that only two oils were group IV:
Mobil 1
Amsoil ASL

All other major oils, advertised as synthetic were Group III:
Castrol
Shell
Pennzoil
Valvoline
Havoline
Quaker

It costs a lot less to manufacture Group III synthetics, but as we all know, they charge about the same as Group IV.

Now, to add confusion, there is a Group V synthetic oil based on Esters, and is used by Redline. The only true benefit of Group V is that it's high heat capabilities are superior to Group III and Group IV. A normal car/truck engine will not benefit by the use of Esters, but it certainly won't hurt. Air cooled and Jet engines benefit greatly with a Group V oil.

Another type of oil that is the "blend." When you mix a synthetic with a dyno oil, the oil takes on the characteristics of the lowest group type used. Therefore, a blend oil is basically worthless. If you are considering a blend, you might as well save your money and go with a dyno or pay more and go with a synthetic.

Most important factor, is always use the recommended spec, or a spec that exceeds the spec for your engine. This is important on systems using oil life monitoring systems. The system algorithms are developed knowing the rate of decline of the oil approved with that spec. Using an oil without that spec would make the system inaccurate. So, the oil life indicator might indicate 50%, but the oil is really degraded to around 30%. Using an oil with a greater spec (synthetic), would also make the oil life monitoring system inaccurate, but won't harm the engine. With an oil that exceeds the spec, the oil life system may show a percentage of 50%, but the oil life is actually at around 70%.

[Wisha Haddan H3]

Originally Posted by RubHer Yellow Ducky

Conventional motor oil is a batch of short-chain and long-chair carbon and hydrogen atoms. In extreme heat, the short chains can evaporate and these unstable molecules oxidize and break down. In addition, contaminants and reactive and/or unstable hydrocarbons can sneak through the refining process.

Thanks for the article RYD. I've read a lot about synthetic vs regular oil, and next to their low-temperature pour point, this part of the explanation is what convinced me to switch to Mobil1 several years ago.

As I understand it, conventional oil meets industry specs based on the average characteristics of its oil molecules, such as size, density, viscosity and oxidation rate, at defined temperatures (with allowable improvements through an additive package). Smaller molecules lower average viscosity in cold temps and larger molecules maintain viscosity at higher temps. But as conventional oil stays in your engine, the smaller less complex molecules evaporate and oxidize first. Thus, the oil's average molecular weight rises due to the attrition of lightweight molecules. It becomes more viscous in cold temps and more corrosive to internal components as acids build up. (The additive package counteracts this corrosion but depletes over time)

To solve this problem, Group IV synthetics were created with PAO molecules of uniform size and weight. To maintain desired viscosity at various temperatures, the molecules were engineered to change shape as temperature varies. At low temperatures, the PAOs coil up (getting physically shorter) for lower viscosity. At high temps, they unwind (physically lengthen) to retain viscosity.

Group IV molecules can still break down under heat and shearing stress. But since there are no lightweight molecules to evaporate and oxidize, their average molecular weight is more stable over time. The coiling and uncoiling maintains the oil's original viscosity parameters and cold weather performance lasts much longer than conventional oil. Due to lower oxidation rates, its acidity also rises more slowly and is countered by the additive package.

To me this means low-temperature pour points, better cold-weather starts and performance, and either better protection at the recommended service interval or at least the same protection over extended intervals.

[raptorman53]

http://neptune.spacebears.com/cars/s.../oil-life.html

Here's a cool web site I found. These guy's did an independant study of synthetics

[deserth3]

Excelent link. It's what I was looking for when I was trying to decide what to put in my truck a few months ago. Thanks.

[Wisha Haddan H3]

Good link, love to see real world results

[HummerHippy]

Oil question. I did a search and did some reading. Wondered about forum folk's impression on oil additives like Slick50, Prolong and similar products in their H3s. I am at about 3200 miles. I'm thinking it's time for the first oil change. THought about adding a little extra protection.

THanks

[Wisha Haddan H3]

Oil additives are marketing gimmicks that make you think you're taking care of your engine. Avoid them like the plague. I researched several of them a few years ago and am convinced that they do little or no good but can cause great harm to your engine.

The ones that contain PTFEs put Teflon particles in your engine. Sounds good because Teflon is non-stick right? Wrong. Dupont (who owns Teflon) states that Teflon is harmful to internal combustion engines. They have to sell it to oil additive companies because it's a free market, but Dupont won't allow the use of the name "Teflon" because of liability.

Other additives bond slippery compounds to cylinder walls for friction and heat reduction. Sounds good right? Wrong. It takes a corrosive acidic action to chemically bond the additive metal to the cylinder wall. Also, the slippery compounds are softer than the metal they replace. They wear away, leaving pits and corrosion in the engine, unless you replenish them regularly with more corrosive additive.

Another reason to avoid oil additives is their secret "proprietary" formulas. You don't know what's in them, and their formulas change all the time due to legal actions and pre-emptive legal defense. They are not to be trusted.

For the best engine protection, use a synthetic oil GM-spec'ed for your engine (like Mobil1) and change it at recommended intervals.

Here's a couple of links to more info.
http://www.carbibles.com/snakeoil.html

http://skepdic.com/slick50.html

[HummerHippy]

Awesome. Thanks for the input and links!

[jp's-h3]

When I had my 86 4runner (211,000 when sold) I used Engine Restore at every oil change. It really seemed to help out! engine ran smooth, burned very little oil, stated right-up!
Most of these oil additives are recommended for high mileage engines. I'm really not sure if it is such a good idea to use any of these additives in a low mileage engine!

[Wisha Haddan H3]

Well, I put my money where my mouth is. The H3 finally said it needed an oil change, so I put in Mobil1 Truck & SUV 5w30 and a Mobil1 filter.

Man that oil was dirty too. I don't think I'll wait so long next time. The engine seems to run smoother, but might be my imagination. Now I'm ready for Ouray ... this weekend

Originally Posted by jp's-h3

When I had my 86 4runner (211,000 when sold) I used Engine Restore at every oil change. It really seemed to help out! engine ran smooth, burned very little oil, stated right-up!
Most of these oil additives are recommended for high mileage engines. I'm really not sure if it is such a good idea to use any of these additives in a low mileage engine!

Nice to know. But I think the fact that it was a Toyota truck had a lot more to do with the good long life (211K) than the use of Engine Restore.

[marin8703]

question about this oil stuff. if you got to synthtic and then back to conventional the engine migth develope leaks at seals or whatever. if you then again switch to synthetic will the seals do good again or still leak.

reason im asking is in our ford i switched it to synthetic, but then i took it to firestone cauze i didnt have time to change it myself and told them to put in synthetic, and thats what the invoice said they did, but after that change i've been noticing some oil on the underside. tomorow im going under it to see whats up.

thanks for replies.

[DURAMAX TIM]

Originally Posted by f5fstop

Last tests I saw showed that only two oils were group IV:
Mobil 1
Amsoil ASL

All other major oils, advertised as synthetic were Group III:
Castrol
Shell
Pennzoil
Valvoline
Havoline
Quaker

OK f5, I use a lot of Schaeffer's oils and grease.

looks like they are a mix of both.

http://www.schaefferoil.com/

[Wisha Haddan H3]

As I understand it, synthetic oil doesn't cause leaks, it just finds them. Probably what happened is you already had a leaky or cracked gasket, but it was plugged with sludge. The synthetic oil just cleaned it out. Of course, now it'll leak until you fix the gasket.

[f5fstop]

Originally Posted by DURAMAX TIM

OK f5, I use a lot of Schaeffer's oils and grease.

looks like they are a mix of both.

http://www.schaefferoil.com/

I have heard of them, but I don't have any experience or test information on their product. They say they meet the GM spec for synthetic, so it is probably as good as any other syn oil.

[marin8703]

Originally Posted by Wisha Haddan H3

As I understand it, synthetic oil doesn't cause leaks, it just finds them. Probably what happened is you already had a leaky or cracked gasket, but it was plugged with sludge. The synthetic oil just cleaned it out. Of course, now it'll leak until you fix the gasket.

thanks, gotta get on that.

[Agriv8r]

thanx for the info...

[algy]

Good read...

I am always baffled at my OnStar oil life report that reads that my oil has 58% remaining when I've exceeded 4K miles. The dealer wants you in at 3K miles and with synthetics OnStar believes that 8K miles you should change your oil. I have been going in every 4.5K miles.