Toyota's reasoning for 0w20 viscosity engine oil

[Artem]

Not sure if this has been posted yet but i found this on a new 2012 Camry while at the dealership.

I agree that 20 grade oils do not necessarily cause more engine wear but the reasoning behind it's use are clearly stated...

"improved fuel economy and to help meet emission standards"

 

[Gokhan]

0W-20 oils have magnesium, which means TBN retention for increased drain intervals. This is because car manufactures specify 10,000-mile drain intervals with 0W-20 and this requires high TBN retention. 5W-20 synthetics don't have magnesium unless they are labeled extended performance, such as Mobil 1 Extended Performance or Castrol Edge. Stay away from magnesium-containing oils unless you want to go more than 5,000 miles on your oil, as it's potentially corrosive and increases wear. Note that magnesium is standard in HDEO because HDEOs are long oil drain by definition and hence the need for TBN retention.

Otherwise, 0W-20 synthetic doesn't have any advantage over 5W-20 synthetic other than a tiny (small fraction of a percentage) increase in fuel economy and extreme cold starts (Canada, Alaska, etc.) Also, synthetic 5W-20 doesn't have any advantage over dino 5W-20 other than less volatility (slightly less oil top-offs).

If you use 5W-20 instead of 0W-20, make sure that you change your oil every 5,000 miles unless it's labeled extended performance (such as Mobil 1 Extended Performance or Castrol Edge), as otherwise, due to lack of magnesium, the TBN retention likely won't be enough to keep your TBN high enough for 10,000 miles.

 

[Zaedock]

Originally Posted By: Gokhan
If you use 5W-20 instead of 0W-20, make sure that you change your oil every 5,000 miles unless it's labeled extended performance (such as Mobil 1 Extended Performance or Castrol Edge), as otherwise, due to lack of magnesium, the TBN retention likely won't be enough to keep your TBN high enough for 10,000 miles.


There are are plenty of 5W20 oils which can exceed a simple 5,000 mile interval.

 

[Artem]

It's strange how magnesium causes corrosive and increased wear on bearing along with extended OCIs don't straight up kill engines.

BTW, i haven't seen any increase in wear from my UOAs with oils that have a bit of Mag.

 

[Gokhan]

Originally Posted By: Artem
It's strange how magnesium causes corrosive and increased wear on bearing along with extended OCIs don't straight up kill engines.

BTW, i haven't seen any increase in wear from my UOAs with oils that have a bit of Mag.

A bit of magnesium obviously makes no difference. We are talking about large quantities of the magnesium detergent, comparable to the calcium detergent. Even in that case, it's only potentially corrosive or wear-inducing. It doesn't mean that it will make a noticeable difference in corrosion and wear. But the main point is that if you're changing your oil every 5,000 - 7,000 miles, simply stay away from magnesium (all 0W-20 oils, Mobil 1 EP, Castrol Edge, and even HDEOs if you don't need them in your passenger car) for peace of mind. On the contrary, if you're going 10,000 miles on your oil, you're much better off with magnesium detergent than without, as your TBN can fall near or below 1 and the acidic oil can instantly corrode your engine.

Here is a scientific paper on magnesium, calcium, and TBN retention.

 

[chubbs1]

I knew they switched to Mag. for something. They want our engines to wear more.


I do agree though that we only used to see mag in Euro or HDEO oils. What gives?

ALL Mobil oils have magnesium now. Pennzoil has kept their formulations similar to their SM formulas.

 

[Artem]

I got cha. I'm slowly extending the OCIs in all my cars as per the UOA report so I need oils that can take the heat and go the distance. Most if not all of the Amsoil oils I use have roughly 12ppm of Mag. That's nowhere near the 200ppm+ I see in other oils.

Thanks for the informative post Gokhan.

 

[Artem]

Originally Posted By: chubbs1
I knew they switched to Mag. for something. They want our engines to wear more.


I do agree though that we only used to see mag in Euro or HDEO oils. What gives?

ALL Mobil oils have magnesium now. Pennzoil has kept their formulations similar to their SM formulas.


They realized that at this rate (10k+ OCIs) and long engine life, we're buying less and less oil / cars so its all a government conspiracy to get our engines to wear faster so we buy more cars and eventually switch back to the 3k rule, I tell you

 

[JOD]

Originally Posted By: Gokhan

A bit of magnesium obviously makes no difference....But the main point is that if you're changing your oil every 5,000 - 7,000 miles, simply stay away from magnesium (all 0W-20 oils, Mobil 1 EP, Castrol Edge, and even HDEOs if you don't need them in your passenger car) for peace of mind.


What are you talking about? The Mg levels in Toyota (XOM), Honda (Idemitsu), Conoco Phillips, Redline, Service Pro...ALL of those oils contain trace amounts of Mg, from 4-12ppm (and these Mg levels are similar to what is found in 5W20 oils?). Avoiding an oil based on 12 of an additive seems beyond ridiculous. The only high Mg formulations I've seen in a 0W20 are from XOM.

As far as 0W20's only providing a benefit in "extreme cold" starts, if you mean "extreme cold" to mean below 100F, then we're in agreement...because the high VI 0W20's are much thinner at start-up in pretty much all temperatures.

To the point of Toyota marketing the 0W20 oils as "fuel saving", here's the disconnect: some people automatically seem to want to assume that anything "fuel saving" must lead to reduced engine protection. This is pretty much the definition of false dichotomy. Engine protection and efficiency are simply not mutually exclusive, and many of the tests done to show thinner oil's suitability have shown it to protect BETTER, not worse. Yet, the deniers of thin oil often continue to dig in their heels on the subject.

 

[Gokhan]

Glancing over the scientific paper above, the oil with the initial TBN of 10 and a Ca:Mg ratio of 6:1 fared best in TBN retention, bearing wear, and oxidation. So, Mg can be a good thing after all.

Again, the primary reason for having Mg is TBN retention for long oil-change intervals. There is a lot of science that goes behind choosing the right balance of Ca and Mg detergents to find the optimal TBN retention and wear protection for used oil. You need Mg, probably a lot of it, for long-drain-interval oils. Can too much Mg be harmful? At one point, it certainly can but it is hard to say at what ratio of Mg:Ca and in what conditions and what formulations.

All said, the oil I use (Mobil Delvac 1300 Super 15W-40) has a Ca:Mg ratio of about 2:1.

I see that they went pretty crazy in Castrol Edge with a Ca:Mg ratio of 4:5.

 

[Gokhan]

Originally Posted By: JOD
What are you talking about? The Mg levels in Toyota (XOM), Honda (Idemitsu), Conoco Phillips, Redline, Service Pro...ALL of those oils contain trace amounts of Mg, from 4-12ppm (and these Mg levels are similar to what is found in 5W20 oils?). Avoiding an oil based on 12 of an additive seems beyond ridiculous. The only high Mg formulations I've seen in a 0W20 are from XOM.

Be careful there. Toyota started specifying 10,000-mile OCIs only recently and chances are that their new 0W-20 formulations have plenty of Mg. When more car manufactures specify 10,000-mile OCIs, you will see that the Mg levels will increase. It's all about TBN retention. Read the paper above in order to understand it.

For example Mobil 1 (except 0W-20, which is a 10,000-mile-OCI oil) SN formulations don't have high quantities of Mg but Mobil 1 EP SN formulations do. Again, it's all about TBN retention. It's the same thing with Castrol Edge, which is astronomical in Mg.

 

[ottotheclown]

Wow a point backed by research , it is right there to read. You do not need to know about an uncle in North Dakota doing 10k oci. You can read research. What is the world coming to???? Much thanks for your info,

why I check this site often you never know!!!

 

[rcy]

Originally Posted By: Gokhan
Originally Posted By: JOD
What are you talking about? The Mg levels in Toyota (XOM), Honda (Idemitsu), Conoco Phillips, Redline, Service Pro...ALL of those oils contain trace amounts of Mg, from 4-12ppm (and these Mg levels are similar to what is found in 5W20 oils?). Avoiding an oil based on 12 of an additive seems beyond ridiculous. The only high Mg formulations I've seen in a 0W20 are from XOM.

Be careful there. Toyota started specifying 10,000-mile OCIs only recently and chances are that their new 0W-20 formulations have plenty of Mg. When more car manufactures specify 10,000-mile OCIs, you will see that the Mg levels will increase. It's all about TBN retention. Read the paper above in order to understand it.

For example Mobil 1 (except 0W-20, which is a 10,000-mile-OCI oil) SN formulations don't have high quantities of Mg but Mobil 1 EP SN formulations do. Again, it's all about TBN retention. It's the same thing with Castrol Edge, which is astronomical in Mg.


VOA done in 2010 on the new silver bottle (Canadian) formula 0w20 from Toyota. This new silver bottle was after Toyota started spec'ing 10000 mile OCI. For comparison purposes, the numbers are also listed from 2009 when I had a VOA done on the original black bottle Toyota 0w20. It was 12ppm then.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1988891&page=1

Magnesium 11ppm (2010 silver bottle), 12ppm (2009 black bottle). Sorry to throw a wrench into your theory.

 

[tig1]

Originally Posted By: Gokhan
0W-20 oils have magnesium, which means TBN retention for increased drain intervals. This is because car manufactures specify 10,000-mile drain intervals with 0W-20 and this requires high TBN retention. 5W-20 synthetics don't have magnesium unless they are labeled extended performance, such as Mobil 1 Extended Performance or Castrol Edge. Stay away from magnesium-containing oils unless you want to go more than 5,000 miles on your oil, as it's potentially corrosive and increases wear. Note that magnesium is standard in HDEO because HDEOs are long oil drain by definition and hence the need for TBN retention.

Otherwise, 0W-20 synthetic doesn't have any advantage over 5W-20 synthetic other than a tiny (small fraction of a percentage) increase in fuel economy and extreme cold starts (Canada, Alaska, etc.) Also, synthetic 5W-20 doesn't have any advantage over dino 5W-20 other than less volatility (slightly less oil top-offs).

If you use 5W-20 instead of 0W-20, make sure that you change your oil every 5,000 miles unless it's labeled extended performance (such as Mobil 1 Extended Performance or Castrol Edge), as otherwise, due to lack of magnesium, the TBN retention likely won't be enough to keep your TBN high enough for 10,000 miles.


All M1 tagged oils, excluding their EP oils, have a 10K warranty. Also I have done 10K OCIs with various M1 oils with very good results. Here is the warranty link.
http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_Warranty.aspx

 

[tig1]

Artem,
Beside the two obvious claims they make on the bottle there are several other bennifits that are listed as well.

 

[Gokhan]

Originally Posted By: rcy
Originally Posted By: Gokhan
Originally Posted By: JOD
What are you talking about? The Mg levels in Toyota (XOM), Honda (Idemitsu), Conoco Phillips, Redline, Service Pro...ALL of those oils contain trace amounts of Mg, from 4-12ppm (and these Mg levels are similar to what is found in 5W20 oils?). Avoiding an oil based on 12 of an additive seems beyond ridiculous. The only high Mg formulations I've seen in a 0W20 are from XOM.

Be careful there. Toyota started specifying 10,000-mile OCIs only recently and chances are that their new 0W-20 formulations have plenty of Mg. When more car manufactures specify 10,000-mile OCIs, you will see that the Mg levels will increase. It's all about TBN retention. Read the paper above in order to understand it.

For example Mobil 1 (except 0W-20, which is a 10,000-mile-OCI oil) SN formulations don't have high quantities of Mg but Mobil 1 EP SN formulations do. Again, it's all about TBN retention. It's the same thing with Castrol Edge, which is astronomical in Mg.


VOA done in 2010 on the new silver bottle (Canadian) formula 0w20 from Toyota. This new silver bottle was after Toyota started spec'ing 10000 mile OCI. For comparison purposes, the numbers are also listed from 2009 when I had a VOA done on the original black bottle Toyota 0w20. It was 12ppm then.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1988891&page=1

Magnesium 11ppm (2010 silver bottle), 12ppm (2009 black bottle). Sorry to throw a wrench into your theory.

Thanks for the link. They are still old (SM/GF-4) formulations though. Also, I don't think Japan is as up-to-date in oil technology as US.

It looks like some, though not a lot, Mg is actually a good thing. The paper above found out that 6:1 Ca:Mg detergent ratio worked extremely well in reducing wear, oxidation, and retaining the TBN in used oil. The conclusion of the paper is that mixed (Ca & Mg) detergents work best in reducing wear, oxidation, and retaining the TBN in used oil, and the precise ratio and formulation should be determined according to the other additives in the oil and actual tests. It's quite complicated science and chances are that many oil blenders don't get it right when they choose the Ca & Mg mix.

 

[CATERHAM]

Here's a VOA on the latest SN GF-5 Toyota 0W-20.
Only 12 ppm of Mg but over 2800 ppm Ca:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2430500&page=1

 

[buster]

Notice Toyota acknowledges start-up wear, which their 0w20 should be great at reducing. I went with M1 AFE for winter. Cold pumpability is important.

 

[Garak]

Originally Posted By: Zaedock
There are are plenty of 5W20 oils which can exceed a simple 5,000 mile interval.


Agreed. However, I think Gokhan is making a valid point, or at least a valid generalization. OCIs are trending longer, and while plenty of modern (and even conventional) oils can exceed 5,000 mile intervals, we've seen changes in oil chemistry and will continue to do so, and a lot of changes will be driven by OCI length. It's already been done in Europe.

 

[buster]

Quote:
. The paper above found out that 6:1 Ca:Mg detergent ratio worked extremely well in reducing wear, oxidation, and retaining the TBN in used oil. The conclusion of the paper is that mixed (Ca & Mg) detergents work best in reducing wear, oxidation, and retaining the TBN in used oil, and the precise ratio and formulation should be determined according to the other additives in the oil and actual tests. It's quite complicated science and chances are that many oil blenders don't get it right when they choose the Ca & Mg mix.


Correct. Oil formulating is an art as much as a science they say.