The surprising truth about motor oils

[Z71]

I have been using Amsoil synthetics since 1975.

I have gone as long as 25,000+ miles w/o an oil change back in the 1970's and 1980's when I was travelling a lot working as a surveyor for a state DOT. I once went nearly 35,000 using Amsoil 10W-40 in a 1977 Monte Carlo back around 1979. I have driven all GM vehicles all of my life and never had one problem using Amsoil and extending my oil drains to 25,000 miles. I have saved a lot of money over the years by not abiding by the 3,000 mile oil change. I have 2 vehicle that are over 12 yrs old and have had yearly oil changes since new, a 1992 Chevy 4x4 PU and a 1993 Chevy Lumina. While both have less than 100,000 miles they are mostly driven around town with the 4x4 being used to plow snow and 95% used in the winter. Both of these engines are like new and never been torn apart for any reason. The truck has been going 2 yrs on the same oil because of the low use. Do I worry about it? No. I have over 30 yrs of experience that tells me it works, contrary to what they non-believers think.

I am not trying to convince anyone of anything nor am I trying to insult them. But on the other hand, all the naysayers that claim you can't extend your OCI or that synthetics are not worth it, are just wrong.

While I am now retired (2002 @ 55yo) from working for the DOT, I still drive about 20,000 miles a year with 4 different vehicles in my personal fleet. 2005 CTS, 2004 GMC are summer weather vehicles and the 1992 and 1993 I drive in the winter. I just kept them because they have been good vehicles I plan to keep till I die.

My summer cruzer, came from GM with Mobil 1 but now has Amsoil in it.

This truck has Amsoil in the axles, engine and trans since new in April 2004. I use it in my small business to make deliveries and tow a trailer about 500 miles monthly.

 

[CT_Tree_Guy]

Mike -

Good stuff. Definitely good stuff. 31 years using Amsoil, that's a long time.

On the subject of extended drain intervals with synthetics, I'm going to exercise my constitutional right to plead ignorance. A possibly irrational part of me keeps thinking that I just want to get all of the suspended contaminants out of my engine, where I can just picture them scuffing up and corroding my cylinder walls and bearings, no matter how good a job the oil is doing of still being oil.

Again, cost rears its ugly head. If a "conventional" drain interval is 3,000, but an oil can stay oil for 30,000, is there some point in between where increased engine life will offset the cost of reducing the drain interval? If so, where is that point? 6,000? 10,000? 15,000? 20,000? Or does it make absolutely no financial difference to go 30,000? It just seems that an engine would have to last longer if the oil were changed more frequently, but again, I am ignorant on this subject, and could be dead wrong to think that. I need more hard data.

Also, what's your "replacement policy" on filters? Do you leave them in for as long as the oil stays in, or change them at certain intervals?

Thanks, John

 

[AutoUnionTypeC]

I use synthetic for pretty much all applications I'm driving a 1997 VW Jetta with 235,000k on her. My only none wear item failure has been one oxygen sensor. I change out during the winter months at 7500 and recently moved my summer interval out to 10000k. I know some will say this is too conservative but as I'm only using Mobil1 I'm sure you'll understand.

My reason for posting is to ask a couple of questions.......
My rational for the early winter change out, is to due my concern about chloride contamination of my oil. Here in upstate N.Y. you often find yourself in a plume of salt dust kicked up from the car in front of you. I know the air filter should clean most of it out yet I have to believe some must get by and in turn some fraction of that must make it into the oil sump. Do I have a valid concern or am I making a mountain out of a molehill? I'm quite not ready to invest in C276 engine components yet; nevertheless the shortened change interval seems prudent.....or not?

Reading through this thread I see you guys joking about the water wars, what's that about. I have access to a DM so my radiator water has to be at least respectable. What kind of mmhos readings are you talking about?

Regards, Jamie

P.S. John, I only responded to you, as you were the last poster.

 

[ronjhall]

<font color="blue"> OK, Daryl, I took some of the blue out of your earlier post. /forums/images/graemlins/wink.gif </font> /forums/images/graemlins/wink.gif
Wow! Bird. Nice job of cleaning up Daryl's <font color="blue"> BLUES </font> . /forums/images/graemlins/grin.gif

 

[Bird]

Daryl, I don't know how you keep up with that many different lubricants and which goes where. /forums/images/graemlins/laugh.gif

 

[HGM]

</font><font color="blue" class="small">( I have been using Amsoil synthetics since 1975.

I have gone as long as 25,000+ miles w/o an oil change back in the 1970's and 1980's when I was travelling a lot working as a surveyor for a state DOT. I once went nearly 35,000 using Amsoil 10W-40 in a 1977 Monte Carlo back around 1979. I have driven all GM vehicles all of my life and never had one problem using Amsoil and extending my oil drains to 25,000 miles. I have saved a lot of money over the years by not abiding by the 3,000 mile oil change. I have 2 vehicle that are over 12 yrs old and have had yearly oil changes since new, a 1992 Chevy 4x4 PU and a 1993 Chevy Lumina. While both have less than 100,000 miles they are mostly driven around town with the 4x4 being used to plow snow and 95% used in the winter. Both of these engines are like new and never been torn apart for any reason. The truck has been going 2 yrs on the same oil because of the low use. Do I worry about it? No. I have over 30 yrs of experience that tells me it works, contrary to what they non-believers think.

I am not trying to convince anyone of anything nor am I trying to insult them. But on the other hand, all the naysayers that claim you can't extend your OCI or that synthetics are not worth it, are just wrong.

While I am now retired (2002 @ 55yo) from working for the DOT, I still drive about 20,000 miles a year with 4 different vehicles in my personal fleet. 2005 CTS, 2004 GMC are summer weather vehicles and the 1992 and 1993 I drive in the winter. I just kept them because they have been good vehicles I plan to keep till I die.
)</font>

Mike,
I would rather stay less confrontational, but my gut wont let me.. /forums/images/graemlins/crazy.gif

20-30,000mi is simply neglect.. I understand that you believe in the product and have experience with it. No problem there,I respect that. I cant make the same claim though, perhaps I have some ignorance built in there too. But, like John said, even though it still has the "oil" properties it is heavily contaminated from normal acids and particualtes that cannot be removed with drain times like that. I'm not really big on 3k mi intervals either, I change my dino oil typicaly between 6-7k and have been known to go 10k beacause I do approx. 33-36k mi per year and its all highway. At 3k I would have to change once per month. at 6k, I do a rotate and bal at the same time. Whether its Amsoil, Quakerstate, olive oil, snake oil, whatever, its not about oil life, its about scrubbing capabilities of the oil. You wouldnt use dirty water to wash the car would you?

Again, I dont mean to offend you and I wish you the best on the vehiles continuing to last you. I just refuse to believe a 25k mi oil change recomendation is good for an engine.

 

[Sully2]

</font><font color="blueclass=small">(
.....
20-30,000mi is simply neglect.. I understand that you believe in the product and have experience with it. No problem there,I respect that. I cant make the same claim though, perhaps I have some ignorance built in there too. But, like John said, even though it still has the "oil" properties it is heavily contaminated from normal acids and particualtes that cannot be removed with drain times like that. I'm not really big on 3k mi intervals either, I change my dino oil typicaly between 6-7k and have been known to go 10k beacause I do approx. 33-36k mi per year and its all highway. At 3k I would have to change once per month. at 6k, I do a rotate and bal at the same time. Whether its Amsoil, Quakerstate, olive oil, snake oil, whatever, its not about oil life, its about scrubbing capabilities of the oil. You wouldnt use dirty water to wash the car would you?

)</font>

I agree 100%

Just because something CAN...dont mean it SHOULD...

 

[Z71]

I only use good filters, never cheap commodity brands. I change filters at the same time I change oil. Back in the old days I would change around 12,000 miles or 6 months. Recently Amsoil came out with a filter designed to go up to 25,000 miles so that is what I will use in my vehicles (btw-Its made by Wix to Amsoil specs using nano-fiber technology licensed to Amsoil by Donaldson) with the next oil changes.

To those who are sketpical of long drains then I suggest its because of the inferior oils you have been using in the past. The oil change industry is just that, an industry based on getting you to change your oil every 3000 miles by scaring you into thinging damage to you engine is very likely if you don't listen to them. GM is saying that millions of miles and years of testing has proven that to be incorrect. In Europe the oil changes are up to as much as 20,000 miles in some makes. Why can they do that but we can't? The oil change industry is the answer. Its a mulit-billion dollar industry counting on you changing your oil every 3,000 miles.

May people are just stuck in a time warp. 3000 OCI were born in the late 1960's when oil was not very good at long term use. Here were are in 2005 and people still follow the oil OCI's. They accept man in space, cell phones, medical advances and other technolgy but build a motor oil to go 25,000 miles. Not possible! I beg to differ.



I better quit before I tick someone off. Many don't like to hear about synthetic oil. /forums/images/graemlins/smile.gif

Read this from GM an dkeep in mind they are referring to dino oil.
</font><font color="blue" class="small">( Typical drain intervals with General Motors’ Oil Life System, the onboard computer algorithm that tells drivers when it’s time to change their motor oil, are 8,500 miles, versus 5,000 for GM’s competitors, a GM executive told last week’s World Tribology Congress. Drain intervals over 30,000 miles are achievable with minor engine modifications and appropriate oil quality. )</font>

 

[Sully2]

"To those who are sketpical of long drains then I suggest its because of the inferior oils you have been using in the past. The oil change industry is just that, an industry based on getting you to change your oil every 3000 miles by scaring you into thinging damage to you engine is very likely if you don't listen to them. GM is saying that millions of miles and years of testing has proven that to be incorrect. "

Strange?? Ive never seen that sort of service intervals EVER published in ANY GM owners handbook! If they TRULY believed that..they should walk the walk...not just talk the talk.

I bought the wife a new car last yeat..NOT a GM car..and in its manual it had 2 different maintaince schedules. Normal and severe duty..?? The defination of severe duty ( to them) was ..."IF you live anywhere that the temps can go BELOW freezing...OR above 100 degrees F..then you need to use the severe schedule!!!!!!!!

Anyone know of anywhere in the the USA you don hit one or the other of those temps??..EVER??

Personally..I never believed in 3000 miles changes even back in the 60's

 

[HGM]

</font><font color="blue" class="small">( May people are just stuck in a time warp. 3000 OCI were born in the late 1960's when oil was not very good at long term use. Here were are in 2005 and people still follow the oil OCI's. They accept man in space, cell phones, medical advances and other technolgy but build a motor oil to go 25,000 miles. Not possible! I beg to differ.



I better quit before I tick someone off. Many don't like to hear about synthetic oil. /forums/images/graemlins/smile.gif

)</font>

Again, I dont have a problem with most of that. I too agree that we have been conditioned to believe that oil will only last 3,000 mi. Times have changed and oils have greatly improved but the point I was trying to make is that no matter how good an oil is, it WILL collect contaminates, thats 30% of why its there. The other 70% is for lubrication and cooling. We all drive in the severe duty range as Sully pointed out so our intervals should naturally decrease from the max. With strictly highway driving I can see longer intervals because the heat cycles are longer and allow more time to burn off the harmfull moisture built up in the engine from condensation, but the other stuff left behind will cause bearing dammage at the least.

BTW, I assume your GM's are out of waranty but if you were to tell the dealer that you changed your oil every 25k like you were supposed to /forums/images/graemlins/wink.gif, I'd be willing to bet they would gladly remove your engine waranty with or withough GM's extended change interval permission or not. Believe it or not its not a conspiracy.

I agree that this can become a heated subject. Whatever works for you, I wish you the best. We can agree to disagree though. /forums/images/graemlins/grin.gif...