Mobil1 0W20 Oil analysis reports

One issue I have with lower weight oils as the xw20 weights is when the engine runs hotter in summertime, the oil will breakdown quicker than say 30 or 40 weight no matter if it is synthetic or not. Main reason cars are now using 20 weight is strictly due to reducing emissions and fuel economy, nothing more than that. The first number of the weight is cold starting, the power the number the better. That being said, looking over your numbers, I am thinking the low TBN is mainly due to the light weight oil. If you were to compare your readings to what I get back from my diesel, I run 9000 between changed and always come back with a higher TBN. In fact they always came back saying run longer. This is using Rotella T non synthetic 15W-40 oil. Another thing to consider is the Prius engine takes longer to break in since it isn't run as hard or as long as a non hybrid engine is. I should probably get a balckstone on my next oil change since I do the double run of oil, I changed the oil at around 5500, then just the filter at 11000, then just changed both at 17000, next one at 22000 will be just the filter, I should send in a sample then and then another at the full change.

 

<div class='quotetop'>QUOTE(bwilson4web @ Nov 21 2007, 07:32 PM) [snapback]542766[/snapback]</div>

Taking Bob's good suggestion to heart, I am beginning to compile virgin oil analyses for all the (known) oils that have UOAs reported for Prius. Source is the BITOG forum, named for that other Bob. Will take some time for this to work its way through my buffer, so if anybody else posts it sooner I would not mind at all.

Jayman, if you are reading, what lab do you use for UOA? The VOAs I see at BITOG are all from Butler or Blackstone.

If anyone knows what oil Toyota uses as a factory fill in Prius, then I might be able to find a VOA for it as well. Or some brand-new Prius owner could just drain off 200 ml? It's probably overfilled anyway

 

<div class='quotetop'>QUOTE(tochatihu @ Nov 21 2007, 11:59 PM) [snapback]542813[/snapback]</div>

Due to cross contamination with the residual oil, it is better to capture 100 ml from the original oil container.

Bob Wilson

 

<div class='quotetop'>QUOTE(ACD @ Nov 22 2007, 12:25 AM) [snapback]542800[/snapback]</div>

I would like to correct a few comments you have made.

First of all, a low ending TBN must be compared to the virgin TBN to derive any sort of meaningful comparison, especially a blanket statement that "light weight oils" contribute to low end TBN.

As an example, according to the virgin tests I had done on Mobil 1 0W-30 and 0W-20 to track down some uoa issues (Turned out to be real crap dealer bulk oil), the TBN was in the 7-9 range.

In contrast, the crap dealer bulk oil had a virgin TBN of 5

Second of all, you absolutely cannot compare a heavy duty diesel engine oil to a regular passenger car oil. A HDEO is formulated to far higher standard than a regular passenger motor oil

Unlike the passenger oil, a HDEO must be overbased to resist acid buildup in the oil. It's not uncommon to find virgin TBN's of +12 for such oils. The HDEO also has far more potent detergent and dispersant additives, to deal with the high soot loads found in modern emission controlled diesel engines

Used viscosity increase, ring land deposit fill, and cold deposit formation are all strictly regulated for HDEO's, especially the newest ACEA E7 and DHD 3 standards. Such standards are specifically excluded from passenger motor oil specifications, unless the oil maker choses to include them. The better synthetics do.

In summer, your Rotella would probably work very well in the Prius, with minimal impact on fuel economy

<div class='quotetop'>QUOTE(tochatihu @ Nov 22 2007, 12:59 AM) [snapback]542813[/snapback]</div>

Toromont Caterpillar SOS labs in Missisauga, Ontario

http://www.toromontcat.com/sos_oilanalysis.asp

 

<div class='quotetop'>QUOTE(jayman @ Nov 23 2007, 09:49 AM) [snapback]543206[/snapback]</div>

No Argument there, but I think you mis read my point. Unfortunately I don't have any records of gas motor oil to compare to, just my truck, but the point I was trying to make is, due to the lighter weight oil, 20 vs 30, the TBN may lower quicker than the 30 weight over the same amount of usage. The rest was just as an example. I do understand oil quite well, was ASE certified back in the mid 90's. Now I am just certifiable.

 

<div class='quotetop'>QUOTE(ACD @ Nov 23 2007, 02:52 PM) [snapback]543315[/snapback]</div>

First I have heard of that. However I did send an email to Toromont SOS lab to get their opinion.

TBN is primarily "used up" by acidic combustion byproducts. There will be far more acidic buildup in short trip cold climate operation

I still believe that one can match an oil to the expected operating conditions and ambient conditions. Bitter cold temps usually justify the lightest possible viscosity, such as 0W-30 or 0W-20. At the opposite extreme, something with better HTHS such as a 15W-40, 5W-40, or 0W-40, may offer better protection

I do find it interesting that xW-20 oils are primarily used only in North America. Ford and Honda have "required" xW-20 oils here for over 10 years, with little negative impact on motor life. The same motors used in other countries usually run much heavier viscosity.

For example, 15W-40 and 20W-50 are popular and common viscosity oils in the Mid East, India, South Africa, and Australia. Haven't heard too much in the way of negative impact on motor life.

My Prius has fine UOA results running Mobil 1 0W-20. My FJ appears to badly shear conventional 5W-30 oils, but running a heavy duty 0W-40 I had good results with no noticeable impact on fuel economy. I just sent off a sample of the FJ running Mobil 1 5W-20 as a "winter" oil, around 3,500 km on it.

If the uoa indicates bad shear, out goes the 5W-20 and in goes the Esso XD-3 0W-40 again.

 

Would be interesting to know if its true.

 

I know it's old but: -

Idling? When does a Prius idle?
Oh nice oil reports.

 

In Adelaide with an average minimum low of 7C (45F), the first minute after starting if you don't move.
At -10C (14F): A WHOLE DAMN LOT!
And when it gets cold: A WHOLE LOT MORE!

You want to see a Prius that gets much WORSE City mileage than Highway? Drive it in cold weather.

 

This is about the highest %fuel I remember seeing in Prius. Your engine just never gets hot, does it?

At some % the fuel dilution reduces lubricity of the oil. Then we should worry. Then, the Al Cu and Fe would rise above your 'barely detectable' levels.

Hope the Si doesn't get much higher on your longer oil run next time. At some level that will act as abrasive and increase the metals also.

 

I wouldn't sweat the fuel dilution at that level. It is meant as a check on engine wear, but by itself is not going to thin the oil out that much from what I can tell. If the oil starts running hotter, it's going to flash off that extra fuel.

I had a pilot plant recip compressor that ran 24/7 in a hard service that it really wasn't suited for. The lubrication specialist swore we were using the right oil, but the bottom ended knocked like hell for the first shift after a fresh start up everytime (usually following a valve rebuild--needed a surge dampener, but that's another story.) I wanted to start up with thinner oil, but I never did. The reason? Enough of our very light product would end up dissolved in the oil after a day or so the oil would thin, the knocking would go away and it would run smooth after that every time. As long as the rings were okay the volatiles content would stabilize via venting. Acids produced by oxidation of the product were a problem for the rings however...which is why it had a gentle nitrogen bleed on the case and was hooked up to the vent system.

 

I may have missed it but do you have all the UOA record in an xls file to share as suggested in an earlier post? Thanks!

 

Sounds great. The twice a year change is in order for my use.

 

Is the boron coming from some additives in the Mobil-1?