I would use any synthetic oil for the changes, if you want to save money, use super tech synthetic or kirkland oil over a conventional oil. Any Dexos Gen 3 oil is what I look to buy.
5k OCI- does oil choice really matter?
- Thread starter BTLew81
- Start date
With DI fuel dilution during the winter and short trips you might not even be able to make it to 5,000 miles.
From my perspective, I prefer using a low cost Dexos 1 Gen 3 approved high mileage full synthetic 5W-30 oil.
The Dexos 1 Gen 3 specification sets stricter limts for sludge/varnish deposits than API SP.
High mileage oils contain seal swellers to prevent oil leaks, and also more phosphorous and zinc anti-wear additives and calcium detergent additives as well.
My oil change interval is 5,000 miles or 6 months (whichever comes first).
The 6 month time component is very important, to protect against sludge/varnish from short tripping in cold weather,
or from fuel dilution.
The Dexos 1 Gen 3 specification sets stricter limts for sludge/varnish deposits than API SP.
High mileage oils contain seal swellers to prevent oil leaks, and also more phosphorous and zinc anti-wear additives and calcium detergent additives as well.
My oil change interval is 5,000 miles or 6 months (whichever comes first).
The 6 month time component is very important, to protect against sludge/varnish from short tripping in cold weather,
or from fuel dilution.
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Patman
Staff member
Let’s be real here though. Dexos1 Gen3 sets the bar pretty low. It’s really not that difficult for an oil to get that approval. That’s why I started using M1 ESP Formula in my Corvette right from the very beginning. It has much harder to achieve approvals on it and I felt confident that it would do a much better job at keeping intake valve deposits at bay (as well as the rest of the engine internals)
I also like to change my 6 month interval in early spring to get the oil contamination from the winter out. Not only does the fuel dilute the oil, it also sucks in salt dust off the road. So spring and fall oil changes for me.
Patman
Staff member
Getting back to the original question here, if 100k is your goal, then you should have no trouble with 5k intervals with any synthetic oil.
But if 200k and beyond is your goal and you want to avoid having higher oil consumption and reduced fuel efficiency as the engine ages, then your choice of oil becomes a lot more critical. That’s where you will want to avoid the more basic low cost synthetics and go for the higher tier stuff
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FWIW, and from my personal experience:
1. In the old days, two friends had the same Toyota Camry, bought at the almost same time
2. One with M1 Synthetic and DIY, the other one conventional, cheap $29.99 oil change
3. Similar driving (70% highway) style and after 100K or so
4. The engine sounds were night-and-day - synthetic = smooth as ever, conventional - louder with some ticking
5. Your OCI seems to be more than adequate (given the low prices of synthetics these days, I would stay with synthetics)
6. Other daily cars' OCI is 6 month / 6-8k miles
7. Another data point I posted here last year for your reference - https://bobistheoilguy.com/forums/t...st-uoa-m1-0w-40-5-000-miles-11-months.382788/
1. In the old days, two friends had the same Toyota Camry, bought at the almost same time
2. One with M1 Synthetic and DIY, the other one conventional, cheap $29.99 oil change
3. Similar driving (70% highway) style and after 100K or so
4. The engine sounds were night-and-day - synthetic = smooth as ever, conventional - louder with some ticking
5. Your OCI seems to be more than adequate (given the low prices of synthetics these days, I would stay with synthetics)
6. Other daily cars' OCI is 6 month / 6-8k miles
7. Another data point I posted here last year for your reference - https://bobistheoilguy.com/forums/t...st-uoa-m1-0w-40-5-000-miles-11-months.382788/
I worked with Mobil 1 engineers, years ago when Mobil 1 was becoming more entrenched in the consumer marketplace. They showed that M1 would last 10k miles and still have solid viscosity numbers. It was dirt and MOISTURE that caused issues with keeping it in an engine that long. They said it probably doesn't matter what you use (as long as in spec for the motor) if you did 3K OCI. I know people that have done 10k OCI with M1 (before you could buy 10k rated M1) and changed their filter every 3K. I'm not going to say "with great results", like many people seem to like to say here with no empirical evidence of what that means, but they drove their cars over 200k with no engine failures. I doubt things have changed that much - moisture is moisture and depending where you live that will hurt the engine and exhaust faster than a place with moderate temps/humidity. Condensate is nasty on oils/metals. So, short drives would contribute to this, as would bad engine designs.
I had checked Lubrizol's website, and Dexos 1 Gen 3 scores 2 grades higher for sludge and 1 grade higher for deposits (varnish) than API SP.
Honestly, we should all be using oil that passes the Mercedes Benz specs, that consistently scores higher than the ACEA and Dexos specs.
Also fine if you plan for 300,000 miles.
Patman
Staff member
Moisture really isn’t an issue unless you’re doing entirely short trips though. The first time you go out on a long drive you’re going to get rid of all of that moisture. The simple thing to do if someone does a lot of short trips is to just take the car out for a 50+ mile drive once a week. Problem solved.
I guess the M1 engineers were clueless, gotcha.
That "moisture burn off" has some truth to it, meanwhile you're ignoring that I did caveat about short trips and I disagree that it's only for "entirely short trips". Once the moisture oxidizes the oil, that's contributing towards getting residue/sludge. That "burn off" is after the fact, but, sure, will help prevent more of it.
That "moisture burn off" has some truth to it, meanwhile you're ignoring that I did caveat about short trips and I disagree that it's only for "entirely short trips". Once the moisture oxidizes the oil, that's contributing towards getting residue/sludge. That "burn off" is after the fact, but, sure, will help prevent more of it.
Exactly right. Folks talk about how their oil has 10k miles and still does well on UOA, blowing off the fact that the oil is absolutely filthy, 5k miles OCIs guys, it’s what God asks of you.
Patman
Staff member
Or maybe you misunderstood what they meant, because excessive moisture isn’t really a factor that we’re seeing in the UOAs here.
Exactly! Even some syn blends are Dexos approved. The bar is low.
They said moisture was a contributing factor towards sludge. What's to misunderstand? High AN's in an analysis would show it, but come on - the people sending their oil in for analysis usually aren't the people not maintaining their engine, right?
Good stuff, and thanks for your service.
Partially. Moisture in the oil accelerates acid and sludge formation. Going for a long drive periodically doesn't fully negate that.
Patman
Staff member
The part where you misunderstood them is simply the fact that moisture isn’t the reason why labs are condemning an oil for future usage.
Yes, excessive moisture is a contributing factor for sludge, but it’s simply not a big reason why a UOA would be flagged. We’re just not seeing it here on the site. You’re new here so take a look in the UOA section and see if you find a report where the oil has been flagged for excessive moisture.
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