On the Rotella website, Shell has mentioned that T4 Triple Protection 15W-40 meets API requirements for SM, SL, SJ, and SH. According to the LR service manual, our trucks require SH or SJ. However, for an oil to meet the requirements for SM, it can only have a maximum of 800 ppm of zddp. SL, SJ, and SH all had a maximum allowed of 1400 ppm and a minimum required of 1000 ppm. What I am confused about is how it makes the minimum requirement of at least 1000 ppm for the older oil standards while not exceeding the 800 ppm for SM. So just by reading the spec sheet for the new Rotella formula, I think that it is safe to say that it probably does not have enough zddp for these motors. We need to find a quality zddp additive or even a break-in oil additive with zddp.

Some useful links I found:
https://www.bobistheoilguy.com/forum...71&type=thread

Shell ROTELLA® T4 Triple Protection | Shell ROTELLA®

 

Thanks for the well researched post.

That's a real pisser.

 

So we have DiscoCam but Disco Mike is MIA kidding asides.

On the link there are some talks about "Maxlife blend using 300 ppm moly and a load of calcium on top of those low GF-4 zddp levels"

Is Maxlife Blend an option then?

 

Are there no other diesel engine oils that still have the ZDDP we want? I know Rotella has been the go-to here for years but is that because there were no others or because "all" others weren't researched?

And (I'll admit I don't have the time right now to do the work, or I'm too lazy) what about the T5 and T6 zinc levels?

 

I'm still reading on it but ZDDP and the levels are being reduced, apparently, because when ZDDP does it job (such as protecting our flat tappet cams) it releases phosphorous, which reduces the efficiency of a catalytic converter. So, again, it is an environment issue messing up my MOJO.

Here is a good chart.

It looks like racing oils and break in oils have high ZDDP, neither of which I am going to buy on a regular basis. Ugh.

A couple of Mobile 1 oils seem to have 1000ppm ZDDP. ...

 

when I first switched to Synth I used Mobile 1 and leaked all over the place. I have been using Rotella T6 for 4 years now and really happy with performance although i know little about oil. I am learning a lot from you guys. bottom of the engine little oily not sure where that is coming from. at some point I want to change the gasket on the oil Pan but looks pain in the neck.

I am still contemplating if I want to stay with T6 or switch to conventional.

 

That's the reason I don't use synthetic except in one vehicle (newer). I did read that modern synthetics do as well as ZDDP at protecting against wear on flat tappet setups. But they were synthetic oil ads.

 

I should add... my Disco has zero rust anywhere. Even in Texas a vehicle of this age should have rust. I attribute it to the tiny oil leak that it has had since day one keeping a little oil underneath. Also, as I've mentioned before, once a year I clean off the frame with Rotella from an oil change. I know, I'm crazy.

 

So what Oil do you use? should I do a engine flush before I switch from Synth to conventional?

I want to see if my small leak stops. Truck only has 89k original miles.

 

I use plain Rotella 15w40.

I don't know of any reasons for a flush.

I'm in a unique position because my oil is essentially free (we get a lot of it for various vehicles, commercially, and it is convenient to use the same in all of them) and I don't drive my rover much anymore (maybe once a week). But I am going to find out how much it would cost to switch the "fleet" to an appropriate oil, once we figure out what that is. That flat tappet issue is a one of a few that ZDDP cures (turbo lubrication is another example) and none of our diesels even have catalytic converters.