My brother has a 89 ctd with 500k on it. All he has ever done is change the oil every 5000 miles with delo conventional oil. I find it hard to believe that synthetics could be any better than that. The motor has outlasted the truck anyway. Just the cost in savings over that many miles could pay for some serious service to the truck anyway.

 

I have been a user of Amsoil for over 20 years. Their products do what they claim. I may be the one who is being fooled but maybe not. If it was not for Amsoil's success we would not be seeing all of the new synthetics out here now, and we would still be hearing the "change your oil every 3K miles" chant.

The synthetics make sense in some applications.

1) If you are willing to run extended drain intervals, the oil is cheaper per mile than good Dino oil. If you are not willing to go with the the long change intervals you will not get one of the greatest benifits of synthetic oil.
In our 97 Chevy Astro at 106K miles I have used 18 quarts of Amsoil, thats pretty cheap per mile. The engine performs and sounds like a new one. Still uses only about 1 qt per 7-8K miles. My 88 Peugeot at 257K gets one oil change per year (about 22k) and is still super clean inside.

2) Winter fuel mileage will be better, summer may be better. A few tenths of a mpg will pay for the oil. I do not hear anyone on this board complaining that they are getting fuel mileage that is better than they want.

3) Some severe applications require synthetic oil. Like the differentials in these trucks. The factory is using it to help the differentals survive at maximum load.

4) Oil anaylsis will show lower wear materials in the oil given the same service conditions in a soud engine running good synthetic oil. This means less wear.
I agree that most of us will not wear out our engines regardless of what oil we use, my motivation for synthetics is 4 fold.

1) Made in USA
2) Better fuel economy
3) Less waste oil
4) Less time under the vehicle (more time to waste here)

I am not here to sell any oil, only to say that one should not bash a product because you don't like their marketing scheme.

Regards,

Jim B

 

I gotta agree w/Windyr.
I've been using Amsoil since early 80s. It hurts REAL bad $$$$ to do an oil change but you don't do them as often so it evens out (I do them yearly).
I wasn't really sold until I had a 77 (I think) ranchero w/ 351 Cleavland block but no hood lock. I was visiting my eventually to be wife and left it sitting in the street in front of her house on LI NY for two days. Sunday night I get in it and start driving home to western NJ . About half way through staten Island it starts to ping and lose power??? so I pull over 5 miles later at the nearest gas station and pop the hood (still running) only to find someone had needed a radiator cap more then I did . I guess since there was no pressure it must have pushed the coolant out before it got hot enough to set off the idiot light. I left it running and slowly put water into it. It was quite a fireworks display with geysers shooting out of the radiator. Once I finally got it filled and calmed down AND paid 12$ for a stoopid cap I finished driving home. I figured I would be lucky to make it all the way to the barn. I was wrong got all the way there. Checked the oil at home and it only smelled a little burnt. I changed it two days later when I got some more oil and a filter and drove it for two more years before I sold it. Dino oil would have turned to asphalt the first time it cooled down.
Ever since then I've used Amsoil in every vehicle I've owned but this isn't an ad because prolly any synthetic would have behaved similarly.

 

Syn makes sense in the tranny & Dif, where God intended it. With the performance from Rotella & Dello, it is not needed in the motor. Consumer Report did a study 5 years ago, or so, of a New York City Taxi fleet, new motors. All differrent types of Oil, including syn. After 100,000, engine tear down, miced. No differrence. Their conclusion for gas motors, buy what is on sale, with the Energy * symbol, sign of SAE standard.The only admiiteed advantage is in EXTREMELY HOT applications & Extremely COLD applications. Otherwise, all you are doing is making Amsoil rich at your expense. You bought the HYPE. Besides, as others have stated, Amsoil is not even rated like the other oils with the SAE/ratings.
Cummins makes no exception for Syn in oil change intervals, filters or not.
Perhaps THEY know something? Just a guess!
Save your oill money, you will need it for diesel fuel.

 

[QUOTE=supr]With the performance from Rotella & Dello, it is not needed in the motor...... , Amsoil is not even rated like the other oils with the SAE/ratings.[QUOTE]

Testing I have done over the last year, on customers oil...I would no longer lump Rotella and Delo 400 together. Rotella is not what it once was. Still good, but Delo 400 has made major upgrades to their blend and is now, IMO, the best quality national brand out there.

Amsoil is SAE rated.... maybe your referring to the API Classifications?

RJ

 

Perhaps it is the API. I know there is a major one it does not have, thtat has been an issue to other members..
Perhaps Delo is better. Both have the Cummins spec, which is the important thing. Both protect your motor.
I know I saw a recent Consumer Report on Delo & Rotela. Delo was better in some chemicals/areas, Rotela in others. Both were far superior to gas engine oil standards.
What does Delo do better?

 

I am really proud of you guys Often tempers rise in these oil threads and they end up completely out of control. But I must say you guys have really done well in this one so far.

Good work guys!

 

When we test customers oil, we do their's and ours... 3" of each oil in a test tube. We add Sulfuric Acid to both, to test TBN efficiency, or ability to neutralize acids.... and we heat both test tubes just short of the boiling point.... to simulate sever usage and in an attempt to simulate 100 hrs or 10,000 miles usage.

Delo 400 repeatedly looks better after this test... forming less (usually none) carbon; also has no burnt smell and has much better color than Rotella, indicating additives still functioning and not depleted.

Rotella also seems to boil at a higher Temp. This may appear to be a good thing, but not so. It indicates heat retention! Since the four functions of an engine oil are to lubricate, clean, seal and cool, an oils ability to disipate heat is important.

Some may take issue with this test as abusive or excessive or unrealistic. It is all of these things, but it is also a valid comparison of how two different oils react to Heat and Acid...two very real enemys of diesel engine oil!

RJ