Oil for a Duramax

TooSlick · Jun 24, 2003

If you are looking for an API licensed, Amsoil has gone and licensed their 15w-40 synthetic blend, "PCO". However, the 15w-40 HD diesel and marine oil is an even better product with a similar additive chemistry, but higher quality basestock blend. Compare the specs of these two oils and you'll see what I mean.

TooSlick

Philip Blackburn · Jun 25, 2003

Why didnt Amsoil get thier other stuff certified?

Why should I put oil in my crankcase that isnt as good? Other than it caries a cert? Amsoil blend shipped to me probably aint exactly cheap so whats the point?

Right now I am thinking shell in the summer and and amsoil or delvac in the winter for the cold weather properties and since it will be worked a bit harder. They both sound like good oils so I will probably go what ever I can get cheaper.

I know I droped a whole lota jack for this peice of equipment and now I am trying to save an extra couple of $$$ but thats the way I am I guess

Still curious why they didnt go for the cert on thier other oil if they got it for thier blend???

TooSlick · Jun 25, 2003

Phil,

I'd agree with you ...if this was my truck, I'd run the Amsoil HD diesel and Marine Oil, supported with oil analysis. I think you'll find it works extremely well in this application and you should be able to extend drains to 2-3 times the normal range with a good test program. If I can be of any assistance, please let me know.

TooSlick

Philip Blackburn · Jun 25, 2003

I dont know of a local dealer

How much for 10qts shipped to peoria IL? Or 3 gallons or a case or what ever would be close to do an oil change?

Or should we switch to email?

Do you know why amsoil didnt get the cert for all thier stuff? Sounds like its easy to pass all the tests. By not having a cert it might scare away customers that would otherwise go with them.

Dick in Falls Church · Jun 26, 2003

There's been a lot of discussion about API certification.
I suggest you go the the AMSOIL home site and read what they have to say.

Philip Blackburn · Jun 26, 2003

I did a search of thier site.....couldnt find anything talking about the cert. Could you point me in the right direction.

Is the price they list what you would pay from a dealer or can you get cheaper from a dealer?

I emailed them with some questions on waranty and such. I didnt relize that they say they will foot the bill. I wonder how much of a PITA it is to get them to make good on thier claim if GM denys waranty work because you didnt use a certified oil?

Dick in Falls Church · Jun 26, 2003

Sorry about that, hadn't been looking for that for a long time and couldn't find it now, either.

If you check the FAQs, AMSOIL states that their oils do meet the required specs. In over 25 years, I have yet to hear of an OEM claiming that use of AMSOIL caused a failure. Can't say the same about some mechanics/technicians.

The listed prices are suggested retail. You can set up an account and save about 25%--contact one of the AMSOIL sponsors for further information.

[ June 27, 2003, 03:32 PM: Message edited by: BOBISTHEOILGUY ]

TexasTDI · Jun 27, 2003

quote:

Originally posted by Philip Blackburn:
Do you know why amsoil didnt get the cert for all thier stuff? Sounds like its easy to pass all the tests. By not having a cert it might scare away customers that would otherwise go with them.

Amsoil oil doesn't carry the API certification simply because it has more phosphorus than the API allows. In all other areas, Amsoil oil meets or exceeds the API's specifications.

Ken2 · Jun 27, 2003

Exceeding a limit is not considered to exceed the spec in any good way!

Amsoil oil that is not API licensed does not qualify for your engine's warranty. Sorry, that's just the way it is.

Schaeffer's oil is API licensed, exceeds all requirements (but doesn't exceed any spec limits), equal or better than Amsoil, and costs less. It is good for extended drain intervals as long or longer than Amsoil, and your warranty is protected as long as you have a good oil analysis at each recommended oil drain interval.

Ken

[ June 28, 2003, 01:22 AM: Message edited by: Ken2 ]

TooSlick · Jun 27, 2003

Texas TDI,

There are no API phosphorus limits for 5w-40 and 15w-40, heavy duty diesel oils. The P limits are only for the xw-20 and xw-30, "GF-3" rated oils that are "Certified for gas engines".

There are several reasons why Amsoil has chosen not to license their 15w-40 HD diesel and marine oil. The bottom line is that the return on investment simply isn't there, and it would limit their ability to make small formulation changes on a regular basis if a better additive chemistry comes along.

The Schaeffers 15w-40 synthetic blend is an excellent oil for this application as well, FWIW.

TooSlick

TexasTDI · Jun 28, 2003

quote:

Originally posted by Ken2:
Amsoil oil that is not API licensed does not qualify for your engine's warranty. Sorry, that's just the way it is.

That depends on the vehicle manufacturer. While my VW's owner's manual does say "you should only use API certified oils", nowhere does it say "warranty will be voided if you don't use an API certified oil".

API certifications are over-rated anyway. Oil specs and oil analysis are what counts.

TS, interesting that phosphorus doesn't apply to diesel oils, even though diesel passenger cars have catalytic convertors. Isn't it true that high phosphorus levels can possibly damage catalytic convertors and that's why the API limits it's amount in oil to meet their specifications?

[ June 28, 2003, 08:32 PM: Message edited by: TexasTDI ]

Bio-T · Jun 28, 2003

Texas TDI,

Many Ford Diesel PSD's use a Cat Conv. and Ford Specs. Diesel oil. Also the Motorcraft oil that Ford uses in the diesel has high Phos. No problems with the Cat. in these vehicles with high miles, 400K+.

TooSlick · Jun 28, 2003

Texas TDI,

If you go to the dealer section of the Amsoil website - in the question/answer section - there is a detailed response as to why all the Amsoil oils aren't licensed. It is too long to go into here.

The 1000 ppm phosphorus limit seems like of arbitrary to me. It's really the amount of oil you burn and the volatility of the P compounds you are using that will determine cat life.

TooSlick

TexasTDI · Jun 29, 2003

quote:

Originally posted by TooSlick:
Texas TDI,

If you go to the dealer section of the Amsoil website - in the question/answer section - there is a detailed response as to why all the Amsoil oils aren't licensed. It is too long to go into here.

Found it. Thanks TS.

Oil for a Duramax

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