Why don't more manufactures recommend synthetics?

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May 6, 2003
We hear how synthetics are the factory fills on some vehicles. Why don't more manufacturers use or recommend synthetics? Some manufacturers are flat out dissing synthetics in favor of just plain old mineral oil. Do they know something we don't or are they just trying to keep maintenance costs lower for the average consumer?
the manufacturers that really are concerned about engine protection will recommend synthetics for the most part. Others are more concerned with keeping maintenance costs as low as possible over the first 3 years of ownership. That statistic is becoming very important nowadays as manufacturers are compared heavily against eachother in terms of cost of ownership within the first 3 years. That is behind the move towards 100,000 mile spark plugs, 100,000 mile tune-ups, longer fluid change intervals for oil and trannies, etc....

Manufacturers building Porsches, Corvettes, Vipers are less concerned with maintenance cost statistics.....
that's my take on it.
One of the points alot of people like when buying a new car is that the engine is so good that they only have to change dino oil every 7500 miles.
But why would some manufacturers diss the synth's? Could it be that the 3000 mile 3 month interval has become a huge money maker for the dealers. The more they get you into the dealership the more you will spend with them.

I would say economics has a whole lot to do with it.

What about the majority of independent mechanics, they push dino too.
yeah toyota is notorious for saying that synth is not required or suggested, and if it is used in the engine, then you can never go back.

It would seem to me that if synthetics really prolonged vehicle life that much, it would cut into some big money on those vipers, corvettes etc. Change your fluids, take care of your car. And it doesnt matter what you use. **** , my uncle ran a chevy malibu to 250,000 on Valvoline. Go figure.. Much longer then I would want to keep a car.
If you compare in the uoa section most syn oils don't seem to show a whole lot of difference in wear numbers on the shorter drain intervals. if you look in the diesel oil section 59 Vetteman posted a ford diesel website link that has alot of Ford powerstroke oil anaylisis' . The difference between the oils are close to being if not equal. It is also good for most people to have their cars serviced every 3,000 miles so the fluids get checked the tires aired etc. the only advantage is cold weather operation and maybe longer drain intervals in a properly running engine.
another reason the manufacturers do not recommend synthetics is they do not pay off for most people, even if synthetics do lengthen engine life (I think they do but it is not proven) most people will sell or wreck their car long before the engine is shot, the only benefit they might see is slightly better gas mileage, not a good pay off for 5x the price

I have owned many cars and until recently they were maintained with dino oil, none were sold with a dead motor, I now run synthetic because my autos are nicer and I am putting a lot of miles on, the synthetics make me feel better about longer Oci's and changing it myself with syn is not much more than paying the quicky lube place to do it with dino (what I used to do)
Most of the owners manuals that I peaked in mentions synthetic oil "if used" should be the viscosity preferred on the chart and changed at the required interval.Most people read that and say "heck with it" why pay more for synthetic if I have to dump it out at the same time as dino (which you and I know you don't) I'll just take it to the quick lube joint and be done with it.The vehicles I service I'm the one that mentions synthetic oil and fewer/lomger returns "to base" for OC's and most people like that idea and go with the synthetic oil,a couple don't and still go extended with dino...whatever gives em a "warm,fuzzy feeling
A lot of manufacturers that use synthetic for factory fill also give free dealer service on scheduled maintenance for the warranty period. Together with the extended oil change interval recommendations, the savings are for the service departments that don't have to do as many oil changes.
The manual for my '96 Volvo hits the point exactly right in my opinion. It says that synthetics are RECOMMENDED when severe conditions of trailer towing, extended high speed mountain driving and/or extremely high or low ambient temperatures are the norm.

Otherwise, the manual recommends 15W-40 dino oil for operating in above freezing conditions and 10W-30 for sub-freezing conditions.

This seems to be a very reasonable approach.

Probably a number of reasons, including the insightful ones posted above. Maybe three more:

1. Since syn can cost 3-4 times more than dino, potentially doubling the cost of an oil change, this might leave a "bad taste" in consumers' mouths that auto marketing departments want to avoid.

2. Even with syn, externally-introduced dirt and internally-produced soot will still tend to turn oil into chocolate milk by the 7,500 mile mark and beyond. So while syn has better shear, decomposition, and temperature qualities, it's not a cure-all: It will dirty from particulates just as fast as dino.

3. Syn isn't what it used to be after Castrol Syntec's b*astardizing of the species, watering it down to something resembling a syn/dino blend, and Detroit knows this.

[ March 06, 2004, 05:29 PM: Message edited by: TC ]
Well for the most part synthetics are not really needed. You can easily get the manufactures programed life expectancy useing the cheapest oil you can buy and a 3000 OCI! THe problem is that most people go at least to the 7500 OCI now recomended by most OEM's. SOme go even longer like 15,000 miles on cheap oil.

THe question you have to ask is what is your life expectancy for this power train? How much parts replacement can I afford to risk? How much time do I want to spend under the car out of warranty changeing fluids? What level of performance do I expect from the powertrain from 36,000-150,000 and again from 150,000-300,000?

It is not a diffacult leap to see how 150,000 miles of 7500 mile OCI with $.84 ST 5W30 is going to differ from 7500 mile OCI with Amsoil, M1, Delvac-1 or Redline! THis will assume no additives or anything like that. Then when you extend that out from 150,000-300,000 their is going to be an insane difference.

Personely I do not want my engine useing a walker and sucking down oxygen from a green tank at 10 years old weezeing black plooms out of it's tail pipe!
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