Rotella 15w40 + MMO, 7415 Mi., '95 Accord EX 2.2l

[gib]

Out of curiosity and for a fun little experiment, I decided to do a nice long MMO run. Hopefully other folks find it interesting as well.

Oil concoction: 4 quarts Rotella 15w40 and 1 quart MMO
Time on concoction: 9 months
Oil filter: PureOne PL14459
Air filter: Fram
I drive mostly mellow highway miles (speed limit is 55 on the freeway almost everywhere in Hawaii) and I generally shoot for maximizing gas mileage.

A few thoughts/notes:

• My original choice for oil was Rotella T5 10w40, but walmart didn't have it, so I grabbed the 15w40 instead. Little did I know that the 15w40 is thicker at temperature than the T5 10w40. Then end result is that this concoction was thicker than anticipated and, by far, the thickest thing I've run in this car. Gas mileage did indeed suffer a bit.
• Previous oil runs, from oldest to most recent, were Castrol Syntec 10w30, PP 5w30, and Mobil 1 HM 10w30. Even though I added .5 quarts at 4k miles to the PP run, I used the same 5 quarts in total as with all other runs (initially put in the manual spec'd 4.5 quarts, then added the remainder at 4k, whereas I usually put in the full 5 quart jug all at once). I don't know why I decided to do it differently with the PP. I wish I hadn't.
• This car leaks oil. Every change I have done has been when the oil level dropped to the low mark on the dipstick, give or take. After I'm done experimenting, which I think will be after my current fill of Mobil 1 0w30 + LubroMoly MoS2, I'll just top off and run longer as it's clear any of these oils could go 10k+ in my application as long as the oil level is kept up.

 

[mongo161]

Thank you for posting your results with the Shell Rotella, Triple Protection, 15w40 and the quart of MMO. Looks like a great UOA with the MMO in the mix.

I plan on changing my oil in the Toyota 4Runner this weekend to a 50/50 mix of Shell Rotella, 15w40 and Formula Shell Dino 5w20. I too don't want to run a diesel oil that is too thick and the Formula Shell 5w20 is thin enough and loaded with Moly for a 5-6K run for the Summer and into the Fall.

BTW....The Shell Rotella T-5, Synthetic blend is not as thick at 10w30. They also make a Shell Rotella, Triple Protection, Dino in 10w30 if you can find it.

Nice results and thanks.

 

[Artem]

That's some thick oil for a car and originally specs 5w30.

I'd be worried about cold flow with the 15w.

 

[Texan4Life]

14 cst with a qt of MMO!? no wonder HDEOs do well with fuel dilution... that or MMO burns off.

 

[mongo161]

I bet that Shell Rotella, Triple Protection, 15w40 really cleaned up your engine. IMO, From what I've read, the Diesel Oils have a really strong add pack with all the calcium, zinc, boron and phosphorus and do some really powerful cleaning on older engines, or any engine that has any kind of build up and needs a fine cleaning.

How dirty was the oil when you changed it out?

Thanks.

 

[gib]

Originally Posted By: Artem
I'd be worried about cold flow with the 15w.

In a cold climate, yeah, but out here I'm not particularly concerned. That being said, I'm definitely a proponent of thinner oils - this was just an experiment for fun. If I ever do another MMO run, I'd make sure to use a thinner oil like Rotella T6.

 

[gib]

Originally Posted By: mongo161
How dirty was the oil when you changed it out?

It was very dark, but that's been normal for this car. Ever since I've completely taken it over as my daily driver, the oil has always drained out very dark. Considering the first 145k miles were done on dino, I'm sure there's been some degree of ongoing cleaning since I've been using synthetics. Diesel spec'd Syntec, PP, and M1 HM are all known to be good cleaners.

 

[steve20]

Where are all the folks who insist MMO drops it a grade?
They used to come out of the woodwork

 

[ltslimjim]

^Rotella isn't exactly a PCMO like most folks using MMO tend to use, I'd imagine. Looks like it didn't hurt the HDEO at all.

OTOH, a PCMO probably would most likely go down a grade(or near a full grade) from a 30 to a 20, for example.

I can see some of where the OP is going with things, but at some point thicker just winds up masking some problems and while you don't save money from gas to save on adding 'more' oil that is lost, I don't get why potentially make the engine work harder for long on a thick blend. Not to say you were going to run what you did during this UOA, but in the event someone were to choose a thicker grade as a 'permanent' solution to leaky gaskets. Burned up valves would be a slightly different issue, though.

I do like the 0w-30/LM MoS2 fill, but that is like bi-polar thin wise. Great move to save on mileage. You could top off with a HM oil exclusively during the current OCI. Any plans ahead of time for a course of action? Just curious.

 

[gib]

Originally Posted By: ltslimjim
I can see some of where the OP is going with things...
[snip]
I do like the 0w-30/LM MoS2 fill, but that is like bi-polar thin wise. Great move to save on mileage. You could top off with a HM oil exclusively during the current OCI. Any plans ahead of time for a course of action? Just curious.

I like thin oils. Running this thick concoction was not an attempt to deal with the oil leak or anything else. Honestly, it was pretty much an accident. I wanted this concoction's viscosity to be similar to the previous oils I've run, so I used two different viscosity calculators to determine what oil I should use to give a final viscosity of about 10.5 cSt. Based on data I could find on MMO (2.6 cSt @ 100C), the calculators indicated I should mix it with an oil that was about 15 cSt. As we can all see, my concoction, after 7415 miles anyway, wasn't anywhere near 10.5 cSt. I'd like to believe the two viscosity calculators I used weren't both ridiculously wrong, but I guess they could be. Another theory is that, at the beginning, the mixture was indeed around 10.5 cSt but thickened up over time/miles as the more volatile components of MMO burned off. That seems plausible, but I don't know for sure.

My future plans are pretty well laid out. The current fill of M1 0w30 + LM MoS2 will be the last of my short OCI experiments where I change the oil when the level drops to the low mark on the dipstick. On all future runs I will top off with a quart of fresh oil when it gets to the low point, then run until it gets back to the low point. That should get me to 11k-13k miles. I don't anticipate trying any more oils as I'll probably stick with Pennzoil or Mobil 1 products. I do intend to keep using the LM MoS2. It's already made the engine quieter and smoother, so I'm sold on it and intend to use it in the other cars in the family fleet as well.

 

[ltslimjim]

^Sweet. Enjoyed your post. +1!

 

[ronrackley]

Very interesting. I ran a fairly extensive sequence of UOAs studying the effects of MMO in Rotella oils a while back:

https://bobistheoilguy.com/forums/posts/2181211/

I found three things consistently: The wear metals, which were always good, were consistently slightly better with MMO in the oil, The viscosity was reduced significantly, but not to the next lower grade and the MMO dropped the TBN a good bit. In fact, running MMO in the gas and not the oil appeared to drop the TBN too.

I'm running Rotella T5 10w30 synthetic blend in that car now without MMO to give it a try. I think the engine is probably very clean inside after all the MMO I ran through it for my experiments. I still run MMO in the gas.

 

[mongo161]

Hey Gib, I changed out my PYB SM, SN, 5w30 today after 6,400 miles in use 70/30 Highway to City miles.

I'm now running a mix of Shell Rotella, Triple Protection, 10w30 Dino Diesel and Formula Shell 5w30 Dino oil in a 50/50 mixed blend. My mix was 3 quarts of each since I used an oversized filter.

I plan on running this mix of oils to early Fall or 7K and then change it out for a Winter Mix of Shell Rotella T6, 5w40 and Formula Shell Synthetic 5w20 on a 60/40 ratio.

 

[gib]

Originally Posted By: ronrackley
Very interesting. I ran a fairly extensive sequence of UOAs studying the effects of MMO in Rotella oils a while back:

Thanks for sharing that. I've been very busy and hadn't followed the forums for the past several months, so I didn't know about your experiments. They certainly put the scientific-ness of my one run to shame. heh
It just takes so long for me to do ~7000 miles, and I don't want to grow old by the time I conclude my experimentation.

Based on your results, it seems I saw a similar drop in viscosity with the MMO mix, about 1.5 cSt. Also, I knew going in that MMO depletes the TBN somewhat, but with my driving over ~7000 miles it was a non-issue as I expected. Based on our results and the results of others, the bottom line is that MMO in the oil, even for longer OCIs, is great for anyone looking for a cleaning or to thin out the oil a bit during winter, as some folks have been known to do.

Lastly, for what it's worth, I had also been using MMO in the gas up until just recently. I did one year without and one year with. Taking account of slight differences in my driving over those two time periods, my gas mileage wasn't affected.

 

[gib]

Originally Posted By: mongo161
Hey Gib

Sounds like a good mix, mongo. I have no doubt it and your planned winter mix will serve you well.

 

[ronrackley]

Originally Posted By: gib
They certainly put the scientific-ness of my one run to shame. heh


I didn't mean to do that. I just wanted to acknowledge that you added another data point to the analysis of MMO in Rotella.

Looking at all our data points, the trends of somewhat reduced viscosities and TBNs - but yet excellent wear metals - emerge very clearly. I think the combination is just excellent for long-term cleaning without much risk of harm. I don't run MMO all the time, but I'm not afraid to use it when I think some cleaning might be a good thing.

 

[gib]

Originally Posted By: ronrackley
Originally Posted By: gib
They certainly put the scientific-ness of my one run to shame. heh

I didn't mean to do that. I just wanted to acknowledge that you added another data point to the analysis of MMO in Rotella.

I was just joking, really. Your tests were excellent, changing each variable to see the effect, but everyone who posts a UOA or VOA adds a little something to the collective knowledge bank. I'm glad you ran your tests and, since I hadn't previously seen them, directed my attention to the results. I appreciate it.