Mazda FF 0W20, 5,017 mi oil/car, 2.0L Gas, US

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First post. Blackstone report on factory fill 0W20, 2015 Mazda 3i Sport, Auto, 2.0L gas, US. Refilled with Castrol Magnatec 0W20. 5,017 miles on both the oil and the vehicle. Cold sample. Vehicle purchased late November 2015 with 55 miles on it. Think it was manufactured early 2015. Oil changed late March 2016. Decent mix of driving but mostly short trips in city.
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Blackstone comments: "Your first sample from your new Mazda has a lot of metal and silicon in it, but don't worry - these results aren't problematic. The extra metal is from new parts wearing in and silicon is from harmless sealers used to put the engine together. It'll take a few oil changes to wash everything out, so we'll just watch for progress until things look more like universal averages, which show typical wear for this type of engine after 6,800 miles of oil use. The 2.3% fuel is cautionary, but some of it may be from cold sampling, idling, or even city driving. Check back for progress"
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MI/HR on Oil 5,017
MI/HR on Unit 5,017
Sample Date 3/28/16
Make Up Oil Added 0 qts
Code:


Aluminum 3

Chromium 1

Iron 39

Copper 44

Lead 0

Tin 1

Molybdenum 608

Nickel 0

Manganese 2

Silver 0

Titanium 0

Potassium 8

Boron 178

Silicon 63

Sodium 9

Calcium 2015

Magnesium 10

Phosphorus 629

Zinc 721

Barium 16



SUS Viscosity @ 210 deg F 48.4 46-57

cSt Viscosity @ 100 deg C 6.78 6.0-9.7

Flashpoint in deg F 340 >385

Fuel % 2.3
Antifreeze % 0.0 0.0

Water % 0.0 0.0

Insolubles % 0.3
TBN

TAN

ISO Code
 
Originally Posted By: atxmazdahonda
Yes, a lot of trips were short. Pardon the new guy- what does "KV" stand for?

KV = kinematic viscosity.
I forget, does your ride have an OLM? If so what did it indicate? Just curious.
BTW, - welcome to BITOG.
welcome2.gif

Kevin
 
It does, but I switched the mode it was in to specific interval rather than the OLM mode. I guess I should switch it back if I know I am going to change it every 5,000 miles anyway.
 
Originally Posted By: Dyusik
That fuel did a number on the KV. short tripper?


It is just what happens if you don't run premium in a skyactiv engine. Not a big deal.
 
Originally Posted By: badtlc
Originally Posted By: Dyusik
That fuel did a number on the KV. short tripper?


It is just what happens if you don't run premium in a skyactiv engine. Not a big deal.

What is it about premium fuel that reduces fuel dilution of motor oil in Skyactiv engines? Does this assertion apply to other engines?
Kevin
 
Originally Posted By: ag_ghost
Originally Posted By: badtlc
Originally Posted By: Dyusik
That fuel did a number on the KV. short tripper?


It is just what happens if you don't run premium in a skyactiv engine. Not a big deal.

What is it about premium fuel that reduces fuel dilution of motor oil in Skyactiv engines? Does this assertion apply to other engines?
Kevin



It is prevalent in just about very modern DI engine. These modern engines have very advanced diagnostic and controls when it comes to combustion. Typically, the DI engines have much higher compression ratios than you'd see pre DI days. In order to maintain compatibility with 87 octane and prevent predetonation, the engine has to run pig rich to keep the combustion temps down. This extra fuel finds its way to the oil.

When you run higher octanes, the ECU can detect it and not only adjust timings but also adjust the A:F and lean it out. I tested this on my skyactiv mazda3. I posted the UOA on this site as evidence to support my claims. On 91 premium, I had no signs of fuel dilution and 0W20 oils stayed perfectly in grade.

This also has the trickle down affect of decreasing risk of intake valve deposits as the less fuel you get into the oil, the less volatile the oil becomes. the less oil volatility means less oil vapors going back through the PCV and creating deposits on intake valves.
 
I don't think they should spec a thin oil like that in a di engine. Too much fuel dilution. I'd put 30 weight in. They would never know it if there was a warranty claim anyway.
That's my advice to you but you.
 
Originally Posted By: badtlc
Originally Posted By: ag_ghost
Originally Posted By: badtlc
Originally Posted By: Dyusik
That fuel did a number on the KV. short tripper?


It is just what happens if you don't run premium in a skyactiv engine. Not a big deal.

What is it about premium fuel that reduces fuel dilution of motor oil in Skyactiv engines? Does this assertion apply to other engines?
Kevin



It is prevalent in just about very modern DI engine. These modern engines have very advanced diagnostic and controls when it comes to combustion. Typically, the DI engines have much higher compression ratios than you'd see pre DI days. In order to maintain compatibility with 87 octane and prevent predetonation, the engine has to run pig rich to keep the combustion temps down. This extra fuel finds its way to the oil.

When you run higher octanes, the ECU can detect it and not only adjust timings but also adjust the A:F and lean it out. I tested this on my skyactiv mazda3. I posted the UOA on this site as evidence to support my claims. On 91 premium, I had no signs of fuel dilution and 0W20 oils stayed perfectly in grade.

This also has the trickle down affect of decreasing risk of intake valve deposits as the less fuel you get into the oil, the less volatile the oil becomes. the less oil volatility means less oil vapors going back through the PCV and creating deposits on intake valves.

So you get higher gas mileage too?
Kevin
 
I read about the potential for deposits on fuel injectors on direct injection engines. I purchased a case of Chevron Techron fuel injector cleaner to use at each oil change (5k mile interval). I can't imagine that the cost difference between 87 octane and 92 octane gasoline is worth the added expense for a couple percentage points of fuel in the oil if I am going to keep changing the oil at a relatively short interval at 5,000 miles. it's something to keep an eye on, however, I wonder if there would still be fuel in the oil with a lot of short trips/city driving if I used premium fuel.
 
This is why I run Mobil 1 EP in mine - it's a much thicker 0W20 and doesn't disappear due to poor NOACK, it's cheaper than the Mazda Moly, and it stands a chance against fuel dilution thanks to the added viscosity. I have had a quieter running engine with just as good fuel economy. You might consider it, since it has a KV of 9.0 instead of a 6.5 range like this wound up being.
 
We have a 2012 Mazda with Skyactive, never did a UOA on it, knowing what to expect from the UOAs of others in here. Thanks for posting.
Brand new engine, Original fill oil, I think it looks pretty good.
Yes, typical Skyactive fuel in oil, they all do.

Interesting theory posted about using premium fuel, I guess something I would have to see and do myself to believe. Just for the fact the motor gets over 30MPG on the highway makes me think the theory of running pig rich using reg fuel vs premium doesnt make sense.

My own theory is that it is the highest compression mass produced engine in the world and some fuel gets by the rings. I dont consider it an issue.

Back to your UOA, bottom line, all this talk about fuel dilation, the viscosity of the oil on your sample is still within its grade!
Anyway, for me, think I would discount the known fuel thing and just look at the metals in your UOAs. Which are not bad for a brand new engine on the original fill of oil.

... just this mornings "thoughts" ....
 
Last edited:
Originally Posted By: alarmguy
Back to your UOA, bottom line, all this talk about fuel dilation, the viscosity of the oil on your sample is still within its grade!


It dropped a grade...we've been over this before, [censored]'s ranges aren't related to J300.

As to the premise that the world's highest compression ratio causes fuel to be forced past the rings... if it's direct injection, there should be no fuel anywhere near the rings.

And pressures during combustion are way higher than that.
 
Originally Posted By: badtlc
Originally Posted By: ag_ghost
Originally Posted By: badtlc
Originally Posted By: Dyusik
That fuel did a number on the KV. short tripper?


It is just what happens if you don't run premium in a skyactiv engine. Not a big deal.

What is it about premium fuel that reduces fuel dilution of motor oil in Skyactiv engines? Does this assertion apply to other engines?
Kevin



It is prevalent in just about very modern DI engine. These modern engines have very advanced diagnostic and controls when it comes to combustion. Typically, the DI engines have much higher compression ratios than you'd see pre DI days. In order to maintain compatibility with 87 octane and prevent predetonation, the engine has to run pig rich to keep the combustion temps down. This extra fuel finds its way to the oil.

When you run higher octanes, the ECU can detect it and not only adjust timings but also adjust the A:F and lean it out. I tested this on my skyactiv mazda3. I posted the UOA on this site as evidence to support my claims. On 91 premium, I had no signs of fuel dilution and 0W20 oils stayed perfectly in grade.

This also has the trickle down affect of decreasing risk of intake valve deposits as the less fuel you get into the oil, the less volatile the oil becomes. the less oil volatility means less oil vapors going back through the PCV and creating deposits on intake valves.


I think you're right about fuel choice in DI engines. My 2015 CRV beat the heck out of viscosity (0w-20 down to 6.8 @ 100C) in only 2,000 miles of Interstate driving. But this included a lot of high-speed driving into a very strong headwind while in "Eco" mode, all of which may have conspired to create detonation on 87-octane fuel and the over-fueling you describe.

Worse, if I understand the concept correctly, is that the viscosity doesn't completely recover after the fuel has evaporated: the fuel compromises the VIIs in the oil and the damage is more-or-less permanent.

My octane conclusion is that, while a spec'd 87 may be perfectly fine for most driving, more demanding conditions call for an octane upgrade. And perhaps staying out of "Eco" mode.
 
Last edited:
I've run 0W-20 (M1 AFE) 30,000 miles in my Skyactiv using three microGreen filters. I used only 87 octane. The oil was still quite serviceable at the end according to the UOA. I don't have evidence to disagree with the premium gas argument, but it hardly seems worth the extra money. I ran a few tanks when I read about it on BITOG and found no significant fuel economy increase, either.
 
Originally Posted By: Shannow
Originally Posted By: alarmguy
Back to your UOA, bottom line, all this talk about fuel dilation, the viscosity of the oil on your sample is still within its grade!


It dropped a grade...we've been over this before, [censored]'s ranges aren't related to J300.

As to the premise that the world's highest compression ratio causes fuel to be forced past the rings... if it's direct injection, there should be no fuel anywhere near the rings.,

And pressures during combustion are way higher than that.


So the question is, if it dropped a grade, what grade did it drop to?
I guess the rest is speculation if all oils do this in the skyactive engine? If so, Mazda is ok with it, if not, switching brands and doing UOAs I guess would make sense.
Or,
Do what I do and use a 5/30, at least for warm weather driving, as in my owners manual, 5/30 is acceptable outside the USA.
 
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