The latest oil spec is API CJ-4... it's on every bottle of every shelf in the diesel oil section of my local auto parts store. During my reading, I kept running into references of older oils being bad for DPF and catalytic converters. I started to raise the question - "Is modern oil good for classic engines like ours?" One might say they're not classic engines - "that's my baby". Our babies are in puberty, and they don't need baby food.

I found this [LINK] and this [LINK], but I won't force you to read them.

What they both say is zinc and phosphorus are good for our engines, but bad for DPF. Only one link mentions calcium in the oil. Going overboard and targeting those ingredients can make the oil less of a lube and more of an engine detergent.

There is still one thing that spooks me, though: The latest oil is targeted for the latest technology - and we don't have that. I have been using Mobile1 Synthetic in all my vehicles (diesel for the 7.3L, gasser type for the cars), but I have not yet seen hard data that explains to me why it would be considered a superior product. I just keep hearing it's the good stuff, without anything to back it up. I found some of the information.

<table width="343"><tbody><tr xmlns=""><td align="" class="bodyText" valign="">SAE Grade</td><td align="" class="bodyText" valign="">5W-40</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Viscosity, cSt (ASTM D445)</td><td align="" class="bodyText" valign=""></td></tr><tr xmlns=""><td align="" class="bodyText" valign=""> @ 100ºC</td><td align="" class="bodyText" valign="">14.5</td></tr><tr xmlns=""><td align="" class="bodyText" valign=""> @ 40ºC</td><td align="" class="bodyText" valign="">97.9</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Viscosity Index</td><td align="" class="bodyText" valign="">153</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Sulfated Ash, wt% (ASTM D874)</td><td align="" class="bodyText" valign="">0.95</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Phosporous (ASTM D4951)</td><td align="" class="bodyText" valign="">0.11 (1100 PPM)


</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Total Base #, mg KOH/g (ASTM D2896)</td><td align="" class="bodyText" valign="">10.7</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">HTHS Viscosity, mPa•s @ 150ºC (ASTM D4683)</td><td align="" class="bodyText" valign="">3.8</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Flash Point, ºC (ASTM D92)</td><td align="" class="bodyText" valign="">215</td></tr><tr xmlns=""><td align="" class="bodyText" valign="">Density @15.6 ºC g/ml (ASTM D4052)</td><td align="" class="bodyText" valign="">0.85


</td></tr></tbody></table>

According to Mobil's self-aggrandizing proclamations, their oil is good for EGR trucks (read - 6.0L). While we don't have a 6.0, older trucks do get a degree of blowby, and oil formulated for EGR will assist with blowby gasses.

I also found the oil for the DPF trucks (not ours) [LINK].

While I appreciate all the testimonials for oils, todays oils haven't been around as long as our engines. The shop guys all say T6 (it's a good price and a good oil), and the scientists say Mobil 1 (about 20 bucks more per oil change). I say I can't find much difference between the two - so it really comes down to shear resistance... our HEUI engines rip the oil. Can we find any data on that?

 

Tugly- so you're saying T6 and Mobil 1 Synthetic are the best choices for our engines?
Or is that your suspicion, and you're looking for information to back that up?

I would LOVE to see a study aimed at out engines. After reading the link you posted in the recent oil thread, I was left wondering exactly what you are: if our oils aren't good for newer engines, are newer oils bad for ours as well?

 

I'm not saying either is the best, I'm saying fleet mechanics feel the Shell Rotella has served them well, and Mobile 1 is highly regarded by the tech-heads. I am sure there are better oils, but I'm trying to balance cost with performance... so T6 and M1 are two heavyweights (pardon the pun) in this ring. If somebody has a good oil in the price range of $20-$25 per gallon, throw it in the ring, but please back it up with some data. Testimonials are good, but they can be subjective if you haven't torn down an engine to back up superficial observations.

If we find an oil with uber shear resistance, that alters the price limitation.

 

The "new" (or current) oils are designed to meet and/or exceed the old specs that existed when our 7.3L's were still in production, as well as meet and/or exceed the new specs of the current emissions controlled diesels. The latest oils aren't just targeted for current technology, but rather they are also targeted to be compatible with the older motors too.

In other words, just because you are using a newer spec oil, doesn't mean your are losing out or sacrificing something.

 

Rotella! 15w40.

 

The 6.0 and 6.4 iirc run much higher hpo pressures than our trucks, wouldn't they require more shear resistance than the oil in our trucks? If so are current oil formulations taking that into consideration or have they gone more by the way of emissions? Are any diesels heui anymore?

 

Don't mean to go off topic here but what the hell is iirc? I never got the memo on that one !!

Smokie

 

IIRC = If I Recall Correctly

Stewart

 

I have used Amsoil products for a long time. This is the oil I use and the specs. They don't mean anything to me, maybe someone could explain them (Tugley?).

TYPICAL TECHNICAL PROPERTIES
AMSOIL Synthetic SAE 15W-40 Heavy-Duty Diesel and Marine Motor Oil (AME)
Kinematic Viscosity @ 100°C, cSt (ASTM D-445) 14.2
Kinematic Viscosity @ 40°C, cSt (ASTM D-445) 93.2
Viscosity Index (ASTM D-2270) 157
CCS Viscosity @ -20°C, cP (ASTM D-5293) 4386
Pour Point °C (°F) (ASTM D-97) -42 (-44)
Flash Point °C (°F) (ASTM D-92) 238 (460)
Fire Point °C (°F) (ASTM D-92) 256 (493)
Four Ball Wear Test (ASTM D-4172: 40kg, 75°C, 1200 rpm, 1 hour), Scar, mm 0.35
Noack Volatility, % weight loss (g/100g) (ASTM D-5800) 6.0
High Temperature/High Shear Viscosity
(ASTM D5481 @ 150°C, 1.0 X 106 s.-1, cP 4.3
Total Base Number 12.1

 

Man I still ain't learned all the computer gorgon yet! Thanks Stewart !

Smokie

 

You're welcome.

Just for FYI sakes, Medusa was a Gorgon in Greek mythology. The word you're looking for is "jargon"

Stewart

 

Did not look right to me either ! Spell checker was not reading my mind !Thanks again! I am dumb enough already ! hate it when I do that!!!

Smokie

 

Hopefully I'm not making an **** of myself here, but isn't the 6.4 common rail?
Shear resistance is the name of the game here, correct? I'd be interested to see HPO pressure differences between the 6.0 and 7.3. Shouldn't be too hard to find.

I believe HEUI is still widely used. International, Caterpillar, and Detroit Diesel all have one or several engines using HEUI in their fleets. The ones I'm not sure about are Cummins, Volvo, Deutz and other more obscure engine makers.

 

If you really, really want to know about oil, go here - Bob is the Oil Guy

You can spend as much time as you like reading and even more time joining and participating in the forums there.

If you have an oil question you think no one can answer, that's the place to go.

 

Here are quotes from the American Petroleum Institute, which is the body responsible for the "CJ4" type ratings.

Its also worth noting that, CJ4 is not the only current API diesel rating. CI4 and CH4 are still being licensed by API.

Tugly, I dont really know what you are asking because your lavish writing style dances around the real question.

Are you asking if CJ4 removes additives that our engine needs?
The answer to that is yes and no. Every brand is different. And some vary A LOT.
I will say that there has been extensive UOA and VOA testing done (even by consumers) and all evidence points to new CJ4 oils being more than adequate. If they werent, you would have heard of it by now.