SkyActiv Oil Analysis Thread
- Thread starter Kedis82ZE8
- Start date
I am in the interesting position of not having done my first oil change yet (2025 CX-5),
so I am hoping to borrow the community wisdom on lubrication matters.
I do not know what it will be like with a 'Skyactive' engine, but in other cars that I have owned, the long intervals that I read about on this and other forums might not be wise.
After five thousand miles the oil in my wife's car has undergone a change of color and has an easily observed viscosity difference. I think that if you expect maximum protection from an oil, it should remain observably the same over the period of use.
Do the CX-5 people who go 5, 6, or 7k miles have oil that looks the same as it did when it was first poured?
so I am hoping to borrow the community wisdom on lubrication matters.
I do not know what it will be like with a 'Skyactive' engine, but in other cars that I have owned, the long intervals that I read about on this and other forums might not be wise.
After five thousand miles the oil in my wife's car has undergone a change of color and has an easily observed viscosity difference. I think that if you expect maximum protection from an oil, it should remain observably the same over the period of use.
Do the CX-5 people who go 5, 6, or 7k miles have oil that looks the same as it did when it was first poured?
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- 2024 CX5 Akera G25
Oil colour doesnt tell the full story by a long shot.
Have a look at the video I linked in post #715.
Mr Speed convinced me, on hard facts and evidence, that changing the oil early, a couple of times before the first factory recommended change on new cars, is well worth doing.
And this one is even more to the point on how to treat new engines.
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Visual appearance means nothing. The viscosity and additives will be fine for way more than the 7500mi interval in the manual. If you want to do the 1st change "early" just do it at 5k. From the factory it has a high-moly oil from Idemitsu (assuming it's the NA engine).
N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
It may hold its viscosity in a test chamber but not when fuel dilution happens. And some of the additives don't last long, at least not the LSPI prevention.
I wouldn't worry about losing this. There are other ways oils can achieve the effects of molybdenum without seeing a high count for it, especially if they are using a version that is 2-3x more effective at the same level, which isn't apparent from an oil analysis. And if they are using boron, that also achieves the same thing but is even better because it works from a colder temperature.
If fuel dilution is a problem, it's an issue with the engine not operating correctly or the sample being taken after lots of short trips and not getting the engine up to temp
Here is my oil test @ 7k mi from 3 years ago on page 23. Oil was regular Idemitsu, not high moly
N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
All of our engines will have fuel dilution, even if they are perfectly operated by a knowledgeable technician. Of course, some people will accumulate more than others due to their driving habits.
Can't tell much on this topic from your oil analysis because we don't know what the viscosity was of the fresh oil. But I can guarantee you there is a steady drop as the miles are added and you approach 2-4% fuel in the oil (which is not apparent from Blackstone's standard test, as it always comes in lower than Oil Analyzers).
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- 2024 CX5 Akera G25
Fuel dilution is a if, but, maybe. Might or might not happen or reach a level that concerns, and the kind of regular use the car gets will be a important factor in that. Eg Predominantly short trips vs highway running.
Metals contamination that WILL happen when a new engine is breaking in, is the primary reason for early oil changes on a new car.
Metals contamination that WILL happen when a new engine is breaking in, is the primary reason for early oil changes on a new car.
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- 2024 CX5 Akera G25
A very courageous statement!There is not a single direct-injected CX-5 that does not have fuel in the oil.
You measured them all?
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- CX5 GT
Based on my experience and oil analysis the Turbo always has more fuel vs the NA engine. Thus changing the oil on Turbo trims more frequently is better idea. It also runs rich by design most of the time even if the car is at operating temp.
The non-turbo can go to 7500 or more if not driven short distances all the time and this engine is less of a problem in ref to fuel in the oil.
The non-turbo can go to 7500 or more if not driven short distances all the time and this engine is less of a problem in ref to fuel in the oil.
N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
Mazda explains why this happens on direct-injected engines. See "making oil", or, why you shouldn't fill your oil to the max level.A very courageous statement!
You measured them all?
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- 2024 CX5 Akera G25
I understand why oil dilution can happen.
MAY is the word used in the Mazda Service Bulletin Number SA-026-18. Is there another SB that says all 2.5 SkyActives WILL suffer oil dilution?
MAY means that something might, or might not happen.
I am not nitpicking with words here either. I guess this is due to my experience in writing employment contracts, industrial agreements and interpreting employment law for many years. That taught me to carefully read all documents and to understand the very important difference between words like “May” and “Will” or “Must”.
Some quick googling suggests that oil dilution is less prevalent in the SkyActive 2.5 NA, particularly more recent years, than many other brands such as Honda, that seems to get a bad rap. Some suggestion that the turbo can suffer dilution a bit more often. My Mazda manual doesnt mention it, but it does mention oil consumption.
Anyway, carry on…
I also noticed that the owners manual recommends a higher viscosity for the Turbo vs the non-turbo for the 2019 models.
These manufacturer suggested longer oil change intervals are having a negative effect (in the long run), specifically where oil sludge build-up is concerned. While the actual oil itself may still have a good lubricating factor, the longer it runs, the more dirt it will circulate around with it through critical moving parts. We are doing 4K miles in our NA 2024. The auto industry is lying to us by saying that some engines can up to 10K miles between oil changes. It's simply a marketing ploy to make you think you are saving money in maintenance in the long run. Take any two same model engines, any make at 100K miles and open them up. The one with 7-10K oil change intervals will be stained dark brown under the valve and the other engine with shorter oil change intervals (say 3-5K miles) will be considerably cleaner (I've watched hundreds and hundreds of tear-down videos and the difference is shocking). Now pull the cams off of the dirtier motor and you will see more wear on the bearings and journals. A worn motor is closer to failing and it is not supplying the fuel economy it once was.
It's even worse in a forced induction motor. The turbo is heating up the oil more than a NA motor would experience. The smart move is to allow the engine to idle for at least 30 seconds before you turn it off once you've parked. Doing so will preserve the bearings inside the turbo because the oil passing through, while the engine idles, will cool it down some. Not doing so will not only slowly cook the bearings, it also cooks the motor oil. Oil coming out of a forced induction motor is always darker than it is out of a NA engine. A 3K mile oil change interval is optimal for turbo charged motor.
And worse even still is the fact that most engines now use the Direct Injection design which eliminates the gasoline washing effect that Port Injection once supplied to the backs of the valves. Today it's all about maximum efficiency. Never mind that these longer interval oil changes and sludge building up behind the valves are slowly shortening the life of your engine. So many things in this world are "disposable" now. It makes me sad.
It's even worse in a forced induction motor. The turbo is heating up the oil more than a NA motor would experience. The smart move is to allow the engine to idle for at least 30 seconds before you turn it off once you've parked. Doing so will preserve the bearings inside the turbo because the oil passing through, while the engine idles, will cool it down some. Not doing so will not only slowly cook the bearings, it also cooks the motor oil. Oil coming out of a forced induction motor is always darker than it is out of a NA engine. A 3K mile oil change interval is optimal for turbo charged motor.
And worse even still is the fact that most engines now use the Direct Injection design which eliminates the gasoline washing effect that Port Injection once supplied to the backs of the valves. Today it's all about maximum efficiency. Never mind that these longer interval oil changes and sludge building up behind the valves are slowly shortening the life of your engine. So many things in this world are "disposable" now. It makes me sad.
N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
You can also just rely on an easy cruise to your house. The airflow coming through helps. There is no airflow when parked.
Not air flow, oil cooling. Besides, a Mazda turbo is positioned behind the block so there is never any air flow cooling on it.
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- 2023 CX5 turbo
yea but it does have the intercooler getting air flow
