Mobil 1 0W20; Mazda 6i 4 cyl; 5000 mi (6K~11K)

[Ashu]

So ... here's my second UOA ...

http://www.therealashu.com/auto/mazda6/UOA/uoa_2nd_2_23_04.pdf

And in image form ...

They (Blackstone) like it, in their little analysis blurb. Iron is apparently consistent with mileage, and reduced copper is a good thing. As is the reduction in silicon. I've highlighted the (few) things that may be of interest, and am wondering whether I should be concerned about the traces of lead and nickel.

To reiterate the background ...
This is the 4-cylinder Mazda 6i with the 2.3l Duratech with Variable Valve Timing Intake Valves. NOT the 6s with the V6 Duratech engine we're seeing WAY more UOAs from!

Oils used:
Original Motorcraft 5W20 oil through 1200 miles
Mobil 1 0W20 from 1200 through 5200
Mobil 1 0W20 from 5200 through 11200

The Motorcraft Cartridge style paper filter from the Mazda dealership was used every time (so this is not some fancy-schmancy after-market oil filter either!).

This vehicle sees occasional auto-crossing, semi-frequent redlining, lots of winter use (heat etc) of course.

Also, it was parked in a semi-heated garage for almost a month, during winter, in the middle of this oil analysis period. Oil was changed within a 1000 miles thereafter.

Expert opinions and observations appreciated. Please do comment on the highlighted stuff, if any of it is relevant beyond normal owner paranoia!

 

[Ashu]

Notwithstanding that Blackstone has already replicated the previous UOA results ... I'm still including a link to all you good folks' observations after the first UOA and previous oilchange ...
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=000985#000000

I'm thinking I'll stick to or around this OCI (5K-6K), considering no better filters are avaible (yet), and the observed marginal insolubles and viscosity. Sound about right?

 

[TR3-2001SE]

This is an excellent report. Mazda builds some great engines and with mobil 1 you can't loose. Wish I had started my Miata on mobil 1 but didn't find this site till later. I'm now doing the 6000 mile mobil 1 thing too.

 

[buster]

This oil is what has me thinking less and less of HT/HS. It's 2.6 cSt. How are their oils not shear down?

Great report BTW.

 

[Ashu]

quote:

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Originally posted by buster:
This oil is what has me thinking less and less of HT/HS. It's 2.6 cSt. How are their oils not shear down?

Great report BTW.

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He he - I only understood the "Great report BTW" part. What language is the rest of your post in?

I'm guessing you're saying the oil seems to be holding up very well in terms of properties?

Newbie question alert!
So is a measured viscosity in the high end of the range BETTER? Like my 58-ish when the normal range is 53 through 59? And here, I thought it had almost crossed PAST the safe range?

 

[buster]

quote:

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I'm guessing you're saying the oil seems to be holding up very well in terms of properties?

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I like oils with good HT/HS but what I am saying is why are oils with 2.6 cSt showing such good wear? I understand (I think) the significance of the HT/HS but when I look at some of these UOA's I start to wonder how important that spec is.

 

[G-MAN]

quote:

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Originally posted by buster:
This oil is what has me thinking less and less of HT/HS. It's 2.6 cSt. How are their oils not shear down?

Great report BTW.

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It's a shear stable oil with an HT/HS of 2.6. That's what it boils down to, basically. The HT/HS numbers don't correlate to how "shear stable" an oil is, i.e., how well it recovers from massive shearing. You can have an oil with an HT/HS of 3.5, but if the base oil and/or VI improver is crap, it's not going to be very shear stable.

 

[TooSlick]

The wear pattern of this engine is already nice and stable, which is what I like to see....

If I wanted to pick nits, I'd say that 3.2-3.4 ppm/1000 miles of iron wear is high for a 2.3L, four cylinder engine. I'd try some of the Mobil 1R, 0w-30 and I think you can reduce the rate of iron wear by 1/3 ....You should be able to run 50% longer than this with the M-1R, so your oil cost will be about the same.

TS