Anti-Synthetic Argument I found on an RV Forum

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Apr 21, 2003
As the title says:

The synthetic oil marketing machine is alive and well!!!

Why do you think that you need synthetic oil? Why won’t conventional oil work just as well?

Either one lubricates in the same way. It provides a lubrication film between the two moving parts to prevent metal to metal contact. When metal to metal contact occurs, the anti wear additive provides protection. For the most part, the same additives can be placed in either oil. (synthetics don’t accept additives as easily as conventional oils do) The big difference between the two is how durable the base oil is under severe conditions.

The mechanism of failure for most engine oils (even yours) is deterioration from combustion by products and contamination by the engine. If it wasn’t for these factors, any oil would last many times longer. The durability of the base stock in conventional oil is not an issue unless some extremely abnormal condition exists.

By changing engine oil at the recommended change interval and using API licensed oil, you change it with a good margin for before the oil fails. If you use synthetic oil and change it before a conventional oil would fail, there is no meaningful advantage to using the synthetic oil.

I don’t recommend it but .... if you extend your changes, a synthetic would only be an advantage if when you determined the point of failure with conventional oil, you could extend beyond that point with a synthetic. For this to happen the mechanism of failure has to be one that synthetic oil could prevent. With the normal mechanism of failure being deterioration from combustion byproducts and contamination by the engine there is no significant advantage to synthetic unless the oil fails for a different reason than it normally does.

So what are you really gaining?????

Pump-ability? Only in very cold temperatures. If you live on the North Slope, you may need a synthetic oil to protect you engine at very low temperatures. If you don’t experience extremely low temperatures, conventional oils with viscosity modifiers have a similar viscosity throughout their working range and there is no meaningful difference in pump-ability.

Chevron Supreme 5W-30 pour point …….minus 33 degrees F
Chevron Supreme Synthetic 5W-30 pour point ….minus 62 degrees F

Less volatile? Not a problem in a passenger car or light truck unless there is a very unusual condition. At high enough temperatures the oil will burn off and carbon deposits will be left behind. The OIL has to actually reach this temperature for it to happen. I know, ….I know, the ads have told you there are areas in your engine that get above these temperatures. BUT…. The oil does not get this hot unless it stays in the area and is allowed time to heat up. Oil that circulates through a high temperature area transfers heat to it but is not there long enough for it to reach a temperature that causes damage to the oil.

Chevron Supreme 5W-30 flash point …….450 degrees F
Chevron Supreme Synthetic 5W-30 flash point ….464 degrees F

Thermally Degradation? Thermal degradation is shortening the oil life as a result of high temperatures over a period of time. This would be a problem if your oil were run at unusually high temperatures for sustained period of time. Unless you were operating way outside of the designed use of you engine, you would never see high sustained oil temperatures. If you managed to abuse your engine to this level, my bet is, you will create problems way beyond lubricating oil degradation.

I have looked at scores of oil sample reports and have spent a lot of time working in this field and have never heard of the problems that the synthetic oil marketeers claim you have protection against occurring in a vehicle that was maintained in some reasonable fashion.

The ad campaigns for synthetic oils make it appear that they happen all of the time. They couldn’t be farther from the truth. Conventional motor oil provides all of the protection you will ever need.

To be honest, hard to argue with his logic. What do you think?
Syns have some distinct advantages low volitility and PP are 2 but with GPII and GPIII coming on I agree with most what he said.
Synthetics last longer & keep your engine cleaner. 20 degrees difference in engine heat could mean major damage versus minor damage otherwise.

Longer OCIs
Less engine gunk
better heat/cold protection

Sorta like an insurance policy in the advent of extreme conditions. It may happen - it nay not!

I figure the insurance policy costs me an extra $7.50 per year based on a 5-quart capacity with 7.5K OCIs/15K driven annually. I'm figuring $1.50 for quart sale dino & $4.50 for quart sale synthetic -- based on the best sellers like Pennzoil, Castrol & Valvoline.

Cheap price to pay just for getting under the vehicle less & knowing the engine's cleaner -- not even figuring all the extreme stuff.

[ November 26, 2005, 05:41 PM: Message edited by: Triple_Se7en ]
Is using synthetics overkill? Maybe, sometimes it is. When it's my cars I'm maintaning I feel a little overkill is perfectly OK.

I've made mention several times that the real experts usually don't respond to many of our questions. You seem to be an exception. I'd like for you to know I appreciate your input.
Just post a few pictures of petroleum sludge.....with folks that do 6K+ OCI's with dino.

Bottom line - synthetic oil has more margin. If your oil change comes up in mid-January with synthetic your car won't sludge so rapidly.

Once again I agree with bruce. I'm at the point now where I use two categories to measure an oil : 1. Good. 2. Not so good. I don't care what base oil is used as long as it's Group II+ and higher, I think your fine. Strong additive package and proven UOA results mean more then what base oil is used. Again, the whole package is what counts. Lubrication Engineers has a article on this topic and it's very similar. This website proves what he is saying in 9 out of 10 cases.
Today's conventional oils ain't grampa's pour-it-out-of-a-glass-bottle sub-Group I's. But the urban legend persists, on BITOG of all places, that severely and very severely hydroprocessed base oils equate to early engine demise. Ignoring common sense operation and engine maintenance are what equate to early engine demise.
Where I live its not uncommon to have to start my car after sitting overnight at -30c.
At that temperature I will stick with synthetic.
- somehow a chunk of my post got deleted - It should say:

If your oil change comes up in mid-January AND you want to delay your change until a warmer day with synthetic, you can put off the change and you need not worry your car won't sludge so rapidly.
Take a look at Mobil's Clean line and Mobil 1 EP. Price and performance are in-line with each's a "push". For our 2 family cars, it would take about 12 oil changes a year if I went by the old 3000mi dino recommendation.
It would be interesting to see how many of the engine manufacturer-required oils (to Mercedes, BMW standards etc) are conventional oils. I doubt that many are, as the extended OCI's have driven the changes to the synthetic and semi-synthetic base oils, presumably to protect against extremes of use.
If you drive in extream conditions most of the time I feel synthetic will not break down or sludge up near as much as dino juice. Extream conditions exist now more than ever if you live anywhere near the city.
I agree with the article and say that conventional oil is plenty sufficient for 95% of the family / daily driver use.

I opt for synthetic for racing, high temperature applications i.e. towing, plowing, off-roading etc.

The conventional oils are significantly improved, the friction surfaces have been reduced i.e. distributorless motors and frankly better materials.

If you are sensible with your motor, keep it tuned up, filters cleaned, changed and run it up to temperature i.e. easy driving at first, you can run conventional oil 8000 miles or more.

Synthetic provides an alternative for some people. But after running conventional oil for 170,000 miles with routine maintenances of 3K OCI I learned one thing....I threw good oil down the drain....after doing UOA's and blackstone every time told me ....if this oil has 4K, 5K, 6K on it, they recommend going another 3k based on the oil condition. Some of that would have put me over 9K or more.

To some synthetic is like a religion, and that's fine with me. Just not necessary....and since I drive 80 miles per day to-from work on the highway, I see my OLM telling me to change at 10K or more.

Not for everyone but good for some.....
Despite the fact that "dino" oil would probably be fine for my OCI, I have stuck with M1 and always will. The price difference is less than half a tank of gas (3.5qt sump), and I'm assured that I won't need to worry about deposits forming, plus the added protection if a water pump goes out, etc. It's only a $10 difference for me (and even less when you factor in the pep boys coupons).

Overkill? Yeah. So what?

I can agree with that, partially. I still think there are cases in which the heavy-duty nature of the application would tend to weigh in favor of using a synthetic, if only for the added margin it would allow if conditions became extreme. I'm wondering, for example, if the Covington's might have avoided their unfortunate V-10 meltdown saga if they had used synthetic instead of the Pennzoil 5w-20. Clearly, there was more going on there than just the type of oil involved, but then again, who can rule out the substantial possibility that a more robust syn might have saved their RV's engine? Here is a link to the Covington saga thread.
With the average cost of $117,500 for an RV the incremental cost of running a synth is statistically irrelevant.

Since extreme conditions can happen in an unpredictable manner and more often than not on the road (RV) away from home, why wouldn't you want to run the best oil available?

True, true...when you look at it as the one unit that you are maintaining, the additional cost of expensive oil or shorter than necessary intervals means nothing.

Now, if you look at it big picture...what if all of the thousands of owners of those big rigs took all of that 'statistically insignificant' price difference from Dino to Syn and threw it into one account. My guess is that there would be PLENTY of extra money left over in that account once the few engine failures from ALL causes (oil related or not) were paid for.

This is what syn oil marketers are banking on...each individual owner is not willing to take the chance of being that one guy who doesn't have a chair when the music stops.

If you applied this logic to everything you bought (always signed up for the 'extra protection' warrantees when available) you'd pay out a lot more than you'd ever save...that's for sure. I think the smart money says don't pay for 'cheap insurance' on anything that you can afford to replace...from a digital camera to a $5K engine.

Thanks for letting me think out loud. Of course when it comes to vehicles, the decision is never purely financial...there is an attachment and pride of ownership that requires a higher level of care than is economically justified!!
I agree fully with the article, especially since most RV's are parked in winter. I have yet to see a UOA that proves synthetic is any advantage in other than severe winter conditions or extended OCI's. A typical motorhome, driven less than 5000 miles a year, and not in sub-zero weather, just needs an annual dino change. The latest SM standard is strict on oxidation and volitility, so high temperatures are not a challenge to the latest dino oils.
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