Synthetic Oil Forever

[SDR]

Thiis is not a diesel question, but figured it might be a good place to post it.





I can remember going into a motor shop in town several years ago and the owner said he wanted me to come to the repair area and look at an engine. He said this is a fellow that never changes oil, only adds oil. The valve area of the V-8 was full of crud!



The other day my cousin drove out from MN to WA in the Corvette and he mentioned to me that he never changes the synthetic oil, only changes the oil filter. My question is; is synthetic oil REALLY that good in a gasoline engine that it never has to be changed ?

 

[Gary - K7GLD]

Basic benefits of decent synthetic oil is greater long-term stability, and greater latitude in temperature extremes.



That said, it's subject to all the same contamination, breakdown, and dilution as any other oil, and unless a good bypass oil filter is used to deal with those conditions, there's no way I'd want to run the same lube indefinitely in any engine I thought very much of...

 

[Drewhenry]

100,000 mile oil change

I used to work for a company in north Texas and one of our employees was once an apprentice working for RollsRoyce. He stated that with the sealed engine the first oil change was due at 100,000 miles. Was that a synthetic? He wouldn't say. What kind of filter? Again tight lipped. I checked and these are realistic figures.

I grew up in New Orleans and my neighbor across the street never changed his oil, only filters and added to get to full mark. He routinely got 200-300k miles out of a car before getting rid of it.

Andy

 

[Gary - K7GLD]

The way a vehicle is driven will have great bearing upon what an owner can "get away with" in terms of maintenance.



Some guys never wash or wax their vehicles either - and get high mileage out of them - and don't CARE how it looks. Other guys won't change lubes regularly either - and don't CARE what the oil or engine internals looks like - or the engine sounds like.



You can get lots more mileage out of oil and engines driven primarily long miles out on the freeway - but try the same thing in short-haul, stop and go around town driving, and poor maintenance and ignoring recommended lube change intervals just MIGHT get co$tly...

 

[steved]

One thing not mentioned... all engines are NOT the same.



Some V8s are notorious for sludging, while others will run forever on the same oil and never sludge. Don't assume what is normal for one is normal for all...



I also know guys that never changed oil, only the filter and topped off... got crazy miles out of those vehicles.



And to further add, what we know of motor oils today is a whole different world of those from yesteryear. Today's oils, combined with today's engine clearances, will last quite a while.

 

[amsoilman]

I will add to what "Gary" said.



The benefits of synthetic lubes are many, as I continually reiterate; Superior wear protection, increased horsepower, cooler running engines, reduced deposits, reduced oil consumption, resistance to oxidation and breakdown, easier winter starts - they all add up to a better running, longer lasting vehicle.



Some Synthetic oils are frequently made from higly refined petroleum base stocks (VHVI and XHVI hydrocracked oils). So, the fully synthetic PAO based, or 100% synthetic oils are very rare. In fact, most of the synthetic oils are petroleum based (mineral) oils. Therefore, you cannot distinguish any difference between them by evaluating smell or color, but there are more benefits to the 100% PAO based fluids.



It is also significant that PAO based synthetics are natural detergents.



Although almost all synthetic motor oils have a detergent package in them, the package can be tailored more carefully due to the inherent detergent action of the synthetic. Also, since synthetics do not break down the way mineral oils do, the detergent/dispersant package is not used up fighting the degradation of the base stock, as can happen in mineral oils. This means extra life for the detergent engine protection.

 

[PRout]

Wayne, I am convinced synthetic oil is more consistent in extreme conditions, and may provide somewhat less friction, less deposits, less breakdown of additive pkgs, etc. After determining my bypass system is reliably allowing extended drain intervals, I decided the Amsoil HD 15/40 Syn is the way i would like to go since i can get long term use out of it, so that justifies and maybe offsets its extra cost a bit.

One thing I have never been clear on, (and I know you will give a straight answer). . I have always "heard' synthetics can get past "marginal" seals and leak easier than dino oils and dino oils tend to expand seals better than syn types. In your experienced opinion, how true is this, and/or would running a mix of dino and syn together be a reasonable choice?

Thanks

 

[SDR]

I thank you all for your input, very interesting remarks

 

[AABEN]

I know of no oil company that says you don't have to change oil. . Go by what the oil company tells you to do. That will be the best thing to do.

 

[JDiepstra]

I know of no oil company that says you don't have to change oil. . Go by what the oil company tells you to do. That will be the best thing to do.

Wow! No offense and not trying to flame but of course the oil company wants you to change your oil! That's how they make money! I think all the quick lubes are still recommending every 3000 miles for an oil change, even though that is pretty much a thing of the past, even in owners manuals.



I never thought I would hear the day when someone on here said do what the oil company tells you to do cause that is the best thing. They are charging us $118 for a barrel of oil and $4. 29 for a gallon of diesel. How is that the best, or even good?



I do agree though that I have never heard anyone advize to never change your oil!

 

[amsoilman]

Wayne, I am convinced synthetic oil is more consistent in extreme conditions, and may provide somewhat less friction, less deposits, less breakdown of additive pkgs, etc. After determining my bypass system is reliably allowing extended drain intervals, I decided the Amsoil HD 15/40 Syn is the way i would like to go since i can get long term use out of it, so that justifies and maybe offsets its extra cost a bit.



One thing I have never been clear on, (and I know you will give a straight answer). . I have always "heard' synthetics can get past "marginal" seals and leak easier than dino oils and dino oils tend to expand seals better than syn types. In your experienced opinion, how true is this, and/or would running a mix of dino and syn together be a reasonable choice?



Thanks

Good to hear you have installed a By-Pass system, which will extend your drain intervals considerably.



As to your question regarding "seals", it would be foolhardy for lubricant manufacturers to build a product that is incompatible with seals.

The composition of seals presents problems that both petroleum oils and synthetics must overcome. Made from elastomers, seals are inherently difficult to standardize.



Ultimately it is the additive mix in oil that counts. Additives to control seal swell, shrinkage and hardening are required, whether it be a synthetic or petroleum product that is being produced.



Sometimes even the manufacturers design a "Seal" or the Sealing surface that is difficult to maintain sealing objectives, so the seal "leaks" even when using a petroleum product. We see it every day in the parking lots!



With that said, if an engine is leaking oil, it needs to be corrected before installing a Synthetic oil, simply due to the costs over the cost of a petroleum.



As too running a "mix" of petroleum and Synthetic together to compensate for "marginal" seals, I would not recommend it. I would however use a "partial" synthetic if the seals were in good condition, but my preference is a "FULL" 100% Synthetic.



Wayne

 

[amsoilman]

I know of no oil company that says you don't have to change oil. . Go by what the oil company tells you to do. That will be the best thing to do.

Well, I know of one that recommends up to 35,000/one year drain interval. Even has it printed on the label.

 

[Gary - K7GLD]

Well, I know of one that recommends up to 35,000/one year drain interval. Even has it printed on the label.

HI Wayne - another question for you.



We are seeing petroleum-based products increasing in price - some quite radically. Since Amsoil lube as offered for our trucks is NOT petroleum based, has their price remained stable, or reasonably so over the last several years?

 

[amsoilman]

HI Wayne - another question for you.



We are seeing petroleum-based products increasing in price - some quite radically. Since Amsoil lube as offered for our trucks is NOT petroleum based, has their price remained stable, or reasonably so over the last several years?

Gary,

The petroleum prices affect EVERYTHING, and it certainly has increased the costs of production as well as transporting the raw materials as well as the finished product. I can remember at one time the cost of just the plastic bottles increased 17 percent! The answer to your question is yes, the prices have increased over the past year or so.



Wayne

 

[PRout]

Thanks for the info Wayne. . Maybe I'll use dino oil for the make-up oil when changing elements to give a bit of a mix. Then use about 80% synthetic on the next change if that sounds reasonable. Right now its at 100% Amsoil 15/40 HD Diesel Synthetic.

 

[Gary - K7GLD]

WELL, truck travel since we moved here to eastern Oregon has dropped to nearly nothing - and more danger of my revered DELO dying of old age in the pan, rather than from actual use!



When I eventually run out of the DELO CI4-Plus I have in stock - three 6-gallon cases worth, I'll maybe switch to Amsoil for it's better resistance to loss of the more volatile elements it provides...