RLI BioSynXtra 5w-40 HD, 5810 mi, 1996 BMW M3

[d00df00d]

Note that copper is an additive in this oil, hence the high ppm reading.

Also note that the car now has over 180,000 miles on it. Given that it seems to have had quite a sketchy first owner (I am the third and the second was awesome), this is something of an achievement.


Summary of the OCI:

- This is actually my THIRD run on this oil. I don't have a UOA from the second because I lost the sample.
- Driving was mixed: highway, suburban roads, and stop-and-go. There was also a fair amount of idling and stationary revs (holding RPMs at 2k or so) from what I did to track down a coolant leak.
- Slightly heavy foot on cold starts, with a fair bit of throttle but never over 2500 RPM until coolant is at operating temp.
- Lots of WOT and some redline every day, especially near the end of the OCI.
- Oil consumption is up from previous runs: about 1 qt/1450 mi.
- I've also had intermittent O2 sensor codes, which seem to have returned after I replaced both O2 sensors.


Wear indicators show no sign of trouble, although obviously we know that's not necessarily an all-clear. The oil itself seems to be continuing to hold up quite well considering the stress. TBN is nice and strong now, which indicates that the chemistry has settled and I could go for much longer OCIs if I wanted.

However, obviously the oil consumption is a bit of a concern. I also suspect that burned oil is fouling my O2 sensors (and possibly plugs), and affecting the tune.

For my next (current) OCI, I've decided to do something a bit different. RLI has a low-ash 15w-40, which I think might help: the lower VII content might help ring seal, and the lighter additization might keep the burned oil from leaving deposits. I'm running that product right now and will pull a sample in 3,000 miles to compare.


On to the report. I've highlighted the top line for better readability:

The other lines are previous samples. In order from top to bottom (click for threads):
RLI BioSynXtra 5w-40 HD (first run)
RLI BioSyn SHP 0w-30
Motul 300V 5w-40 #2
Motul 300V 5w-40 #1
Motul 8100 X-Cess 5w-40

 

[benjamming]

I don't know how the extra 4qts would normalize exactly, but nitration looks good. I wasn't expecting it to be that good after reading your comment about tune.

How much copper is additive & how much is wear?

 

[addyguy]

Darn that oil is LOADED!

Held visc. nicely, even in the presence of significant fuel.

 

[dparm]

I see the antimony is still "low" compared to the 0w30 and others RLI is selling.

 

[d00df00d]

Originally Posted By: benjamming
How much copper is additive & how much is wear?

Can't say for sure, but my understanding is that most if not all is additive.

 

[gathermewool]

Curious to see whether you have better luck with the 15W-40. I'm still very interested in this oil, but need to see more high-stress apps PUSHING the oil.
My recommendation: take the 15W-40 out to 20kmi! With all of the additive replenishment that shouldn't be a problem.

 

[d00df00d]

Originally Posted By: gathermewool
My recommendation: take the 15W-40 out to 20kmi! With all of the additive replenishment that shouldn't be a problem.

Believe me: if I could, I would.

Given the TBN on this UOA, the 5w-40 HD (or any RLI xw-40 with the HD additive pack) should be good for 10k miles. I just can't shake the idea that, with all the oil consumption, the heavy additization is hurting (through deposits) as much as it's helping. The low-ash version of the 15w-40 might run longer if it holds up better, or it might not run as long because it's lighter on additives. We shall see.

 

[gathermewool]

Originally Posted By: d00df00d
Originally Posted By: gathermewool
My recommendation: take the 15W-40 out to 20kmi! With all of the additive replenishment that shouldn't be a problem.

Believe me: if I could, I would.

Given the TBN on this UOA, the 5w-40 HD (or any RLI xw-40 with the HD additive pack) should be good for 10k miles. I just can't shake the idea that, with all the oil consumption, the heavy additization is hurting (through deposits) as much as it's helping. The low-ash version of the 15w-40 might run longer if it holds up better, or it might not run as long because it's lighter on additives. We shall see.


Interesting thought (RE: additives hurting over the long haul.) At least based on your current UOA, it doesn't seem as if there's much concentration by reduction going on, though I'm sure we don't have the full picture. Also, with an aggressive cleaning add pack and zero "soot," is it really a concern?

It'll be interesting to see your results. If you can break the 10kmi barrier, then I'll most certainly give RLI a try. I'l be draining my current run of Amsoil Euro 5W-30 in another couple of months. I've got enough for one more OC, so I've got until the end of the year to figure out what my next move is.

 

[d00df00d]

Now that the chemistry has settled, I don't think there's any doubt that I could run 10k miles on the 5w-40 HD.

As for my additive hypothesis: I'm sure anywhere the oil circulates is squeaky clean. What I'm worried about are piston tops, valves, O2 sensors, etc. -- areas where burned oil can leave deposits but that circulating oil can't keep clean.

 

[gathermewool]

Originally Posted By: d00df00d
Now that the chemistry has settled, I don't think there's any doubt that I could run 10k miles on the 5w-40 HD.

As for my additive hypothesis: I'm sure anywhere the oil circulates is squeaky clean. What I'm worried about are piston tops, valves, O2 sensors, etc. -- areas where burned oil can leave deposits but that circulating oil can't keep clean.


Ah, that makes sense. I guess all you can do is use a good FI cleaner or suck some water into the intake tract occasionally to keep things clean. I'm too chicken to try the latter, but who knows after another 50kmi.

 

[d00df00d]

RLI's 5w-40 HD has around 1.3% sulfated ash; the 15w-40 low-ash has around 0.9%. The 15w-40 obviously has less VII content, and apparently the low-ash additive pack is a bit lighter in other ways (although not much isn't lighter than the HD formulations). I'm hoping that those features reduce deposit formation.

Obviously, I will be compromising on antioxidants and acid fighters, which may be problematic with the fuel dilution. Worse cold pumpability is a given. Apparently the low-ash formulas trade some detergency for dispersancy; I'm not sure what the implications of that will be. Lastly, only the HD formulations have the copper additive, which is supposedly good for keeping upper piston rings clean (per Bill at RLI). I'm just hoping that the potential gains (better combustion chamber sealing, lower volatility, cleaner additive pack) materialize and offset the losses.

 

[d00df00d]

Something else I've noticed and forgot to mention earlier: It seems that this oil (the 5w-40 HD) would let me go by the car's OLM without worries.

At the time I pulled this sample, the car's OLM seemed to indicate that I could run something like 40% longer before a change would be ideal, and 50%-60% before a change would be absolutely necessary. Those indications seem to match the condition of the lube fairly well. Food for thought, IMO. Hopefully the low-ash 15w-40 won't be too far off in this respect.

 

[gathermewool]

Your basic assumption is that deposits are being formed now and aren't being cleaned by normal function of the port injectors. It may be that your valves are fine, or have only minor deposits - nothing a good PEA-based cleaner every now and again can't handle. Also, it might end up that the 15W-40 is consumed at a lower rate AND produces fewer deposits for the amount consumed.

Also, with how well you maintain your motor (but with consumption,) the dispersants will be more important than the detergents - things are probably pretty clean.

 

[d00df00d]

Originally Posted By: gathermewool
Your basic assumption is that deposits are being formed now and aren't being cleaned by normal function of the port injectors. It may be that your valves are fine, or have only minor deposits - nothing a good PEA-based cleaner every now and again can't handle.

Suspicion, not assumption.

Also, I'm not just worried about my valves. As I said earlier, I'm worried about my O2 sensors as well. Correct me if I'm wrong, but I don't think fuel system cleaners can be relied upon to clean those.


Originally Posted By: gathermewool
Also, it might end up that the 15W-40 is consumed at a lower rate AND produces fewer deposits for the amount consumed.

That's the hope.


Originally Posted By: gathermewool
Also, with how well you maintain your motor (but with consumption,) the dispersants will be more important than the detergents - things are probably pretty clean.

Good point.

 

[gathermewool]

Originally Posted By: d00df00d
Originally Posted By: gathermewool
Your basic assumption is that deposits are being formed now and aren't being cleaned by normal function of the port injectors. It may be that your valves are fine, or have only minor deposits - nothing a good PEA-based cleaner every now and again can't handle.

Suspicion, not assumption.

Also, I'm not just worried about my valves. As I said earlier, I'm worried about my O2 sensors as well. Correct me if I'm wrong, but I don't think fuel system cleaners can be relied upon to clean those.


Originally Posted By: gathermewool
Also, it might end up that the 15W-40 is consumed at a lower rate AND produces fewer deposits for the amount consumed.

That's the hope.


Originally Posted By: gathermewool
Also, with how well you maintain your motor (but with consumption,) the dispersants will be more important than the detergents - things are probably pretty clean.

Good point.


No, I guess I missed your comment about the O2 sensor - the pain of impatience and replying via phone. haha I can't imagine the exhaust byproducts of PEA carrying over and doing anything to clean the O2 sensor, but I honestly have no idea.