Conventional oil = semi synthetic?

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I don’t refuse to be educated. When I was in school that is what we learned and that’s what I stuck with. I respect what everyone says but my habits will never change.
You do realize that industry practices evolve over time due to findings and newer technology, right?
 
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I don’t refuse to be educated. When I was in school that is what we learned and that’s what I stuck with. I respect what everyone says but my habits will never change.
I took Auto classes all the way through highschool. Never in our classes were we taught that there was a some specific mileage number to change oil, synthetic or otherwise.

Now I can point to one instance where it's important to have the oil changed early and that's in racing. After highschool I was helping a friend of my dad's work with a late modified dirt track racing car at our local dirt-track. That car being used for racing purposes,we changed the oil the next weekend before the races again that Saturday night.
 

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Yep and we all learn all the time in this industry.

But that runs entirely contrary to your earlier statement:

AutoMechanic said:
When I was in school that is what we learned and that’s what I stuck with. I respect what everyone says but my habits will never change.

Those two statements are not compatible; they are contradictory. You aren't learning if you aren't accepting new information and changing your behaviour based on that. It would be like me installing 3COM 10-baseT hubs now and demanding my customers use ISA NIC's because that's what was current when I learned networking.
 
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But that runs entirely contrary to your earlier statement:



Those two statements are not compatible; they are contradictory. You aren't learning if you aren't accepting new information and changing your behaviour based on that. It would be like me installing 3COM 10-baseT hubs now and demanding my customers use ISA NIC's because that's what was current when I learned networking.
Well it’s just my opinion. To me anyone that goes over 5k on an oil change is crazy. Have you seen some of the under valve cover photos here recently that have went over 5k the engines were dark and sludgy that’s why I don’t stand to the manufacturer of the oil or car recommending going 10,000 miles. And on those everyone says to shorten the interval including some people here who are saying I’m wasting oil changing at 5 months or 5,000 miles.
 
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Because don’t want it to start going bad and it’s synthetic so a general rule of thumb is 5000 or 5 months.
I know Project Farm gets a lot of hate on here, but he did a used oil analysis on his diesel truck oil after having it in the sump for a year and everything came back fine.

BITOG in general seems to be a land of extremes, but I think modern oil in a modern engine will be fine at yearly to 18 month changes. And personally I'd go with 4000-6000 mile OCIs regardless of the "science" behind longer ones just as a gut instinct/feeling. In my case I do a lot of short trip and city driving, so that's probably where my opinion comes from. I guess it's theoretically possible some car with 80% highway running could get 10K comfortably on oil changes, but I don't drive that way.

One kind of weird situation I did that was still stupid was when I was a teenager I ran fabric K&N style cone filters on my cars to be a ricer and to make "woosh" noises with my intake and feel cool. I noticed running those my oil would get absolutely black much faster compared to the OEM paper ones. With most of my cars with paper filters unless there was some pre-existing sludge, my oil took 3000ish miles to get darker brown, with fabric cones it would be there at 1500 or so miles. Now I just run an OEM filter as the (mostly nonexistent) power gains aren't really worth it, but if I had a recreational car with a cone filter on it again (I've actually heard AEM Dryflo filters are the best at actually filtering vs K&N, so likely I'd go with one of those...) I'd probably be changing my oil at 2500 or so miles, just because of the amount of dust that gets into your oil and stays in suspension. So the higher oil change frequency might save some bearings/etc in that case. Of course the better thing is not run that kind of filter, but if you had some sort of sporty car where it was worth it to run a filter like that, then it's also probably worth it to do 2000-2500 mile short OCIs.
 

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Well it’s just my opinion. To me anyone that goes over 5k on an oil change is crazy. Have you seen some of the under valve cover photos here recently that have went over 5k the engines were dark and sludgy that’s why I don’t stand to the manufacturer of the oil or car recommending going 10,000 miles. And on those everyone says to shorten the interval including some people here who are saying I’m wasting oil changing at 5 months or 5,000 miles.

Yes, and there have been plenty of oils going longer than 5K where the engine is spotless. You can't just bring up the one side of the anecdotal data that supports your opinion and ignore the other.

Some engines are not tolerant of longer drain intervals, some engines are extremely tolerant of longer drain intervals. Some engines will look absolutely awful no matter what the interval is because they are simply hard on oil. The Honda 3.5L VCM engine is an example of that.

Have you seen the pictures @tig1 has posted of his Mobil 1 engines?

What about this engine on Ravenol:

10K OCI's.
 
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Yes, and there have been plenty of oils going longer than 5K where the engine is spotless. You can't just bring up the one side of the anecdotal data that supports your opinion and ignore the other.

Some engines are not tolerant of longer drain intervals, some engines are extremely tolerant of longer drain intervals. Some engines will look absolutely awful no matter what the interval is because they are simply hard on oil. The Honda 3.5L VCM engine is an example of that.

Have you seen the pictures @tig1 has posted of his Mobil 1 engines?

What about this engine on Ravenol:

10K OCI's.

I think it depends on pre-existing factors. Notably, that car has a 5.5qt sump for a 2L 4 cylinder engine, which is a slightly larger sump than average. Something like newer Mustangs having a 10qt sump, I could totally understand going 10K on an oil with, as they have double the oil capacity overall. A 1990s Honda or a Nissan with a 3.5qt sump probably wouldn't do as well with the oil just because there's less oil circulating. The car is also new, and he was the one servicing it with some of the best oil he could buy. On a used car with questionable maintenance history and possibly pre-existing sludge, not all of it will ever wash away, and you're going to have more sludge and junk in suspension every oil change for quite a long time.

He's also using $55 a jug oil, and his total oil change comes to probably about $70, whereas if I use Valvoline or Supertech my oil changes are in the mid $20 range all said and done. So I could do 3 oil changes for the price of one 10K one with said Ravenol oil. So 3x5000, 15K for the same price. Sure, it's more time under the car and dropping off used oil at Advance, but all of my vehicle fleet basically gets about 10-12K miles per vehicle, so it's twice a year for a 20-30 minutes under my car and dropping off oil before/after some other errand. I will freely state that I am broke and am not a CEO where "my time is more valuable than that!" where I could be using that combined hour or so of oil changes to work on a thesis, more than likely I'd probably spend it on a forum like this or playing video games.

I think if people are making an informed choice and using an appropriate oil with 10K oil changes that's great, but I still would not feel comfortable recommending a 10K oil change as a rule for the majority of people. You also need to understand if you tell people 10K, they may take it 15, etc. If you tell them 3, they'll do 5, tell them 5, they'll do 8, etc. I've always been a 3-5K person, but I've taken some oils to 6000-8000 before, and I think that doing that with 10K and taking it to 12-15K could be disastrous.
 

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I think it depends on pre-existing factors. Notably, that car has a 5.5qt sump for a 2L 4 cylinder engine, which is a slightly larger sump than average. Something like newer Mustangs having a 10qt sump, I could totally understand going 10K on an oil with, as they have double the oil capacity overall. A 1990s Honda or a Nissan with a 3.5qt sump probably wouldn't do as well with the oil just because there's less oil circulating. The car is also new, and he was the one servicing it with some of the best oil he could buy. On a used car with questionable maintenance history and possibly pre-existing sludge, not all of it will ever wash away, and you're going to have more sludge and junk in suspension every oil change for quite a long time.

He's also using $55 a jug oil, and his total oil change comes to probably about $70, whereas if I use Valvoline or Supertech my oil changes are in the mid $20 range all said and done. So I could do 3 oil changes for the price of one 10K one with said Ravenol oil. So 3x5000, 15K for the same price. Sure, it's more time under the car and dropping off used oil at Advance, but all of my vehicle fleet basically gets about 10-12K miles per vehicle, so it's twice a year for a 20-30 minutes under my car and dropping off oil before/after some other errand. I will freely state that I am broke and am not a CEO where "my time is more valuable than that!" where I could be using that combined hour or so of oil changes to work on a thesis, more than likely I'd probably spend it on a forum like this or playing video games.

I think if people are making an informed choice and using an appropriate oil with 10K oil changes that's great, but I still would not feel comfortable recommending a 10K oil change as a rule for the majority of people. You also need to understand if you tell people 10K, they may take it 15, etc. If you tell them 3, they'll do 5, tell them 5, they'll do 8, etc. I've always been a 3-5K person, but I've taken some oils to 6000-8000 before, and I think that doing that with 10K and taking it to 12-15K could be disastrous.

Sure, there are myriad factors, which I touched-on earlier in the thread. I use Ravenol in my SRT and change it via the OLM, I use M1 EP 0w-20 in our RAM and change it via the OLM too. I historically ran longer (10-12,000km) OCI's on Mobil 1 in numerous Ford Windsor engines that were exceptionally clean when torn-down, so I'm comfortable with intervals longer than some being discussed here.

My point was that there's no universal standard for 3 months/3000 miles; the oil doesn't "go bad" in that amount of time, and Synthetic doesn't go bad in 5 months/5000 miles, which are the intervals the poster in question is adhering to. That could mean the oil gets changed at 500 miles if the car isn't operated much in that period, which is ridiculous and a waste of resources.

No, not everyone is going to fine-tune their OCI length based on UOA's, and that's understandable, but there's gotta be a bit of thought put into what length makes sense. Most modern vehicles have OLM's at this point, and these are, in many cases outside of specific demanding Euro approvals, often calibrated for the cheapest oil that meets the spec, which, depending on the age of the vehicle could be a conventional oil. That's the case for the HEMI, so I have absolutely no problem following the OLM with a premium extended drain lubricant which I'm likely under-utilizing if I were to get it tested.

My last two OCI's in the truck, using the OLM, were 10,478km (6,508 miles) and 11,673km (7,253 miles), respectively.

My Jeep OLM will call for shorter OCI's, despite factory-spec'ing a synthetic 0w-40, because the SRT engines are expected to be harder on oil.
 
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Wait, so if you only get 500 miles on in three months you change the oil? o_O Dude, that's a shorter OCI than what people did in 1950.
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Yes and I visit it frequently. My conventional goes to 3 months or 3,000 miles. The synthetic goes to 5,000 or 5-6 months for me usually. I’m old school.
In many ways I'm old school also. For the last 43 years I have done 10K (miles) OCIs with M1 oils in various engines. That's old school for me. All engines remained very clean, even some with high miles, none ever increased in oil consumption, and none never showed signs of unusual wear.
 
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I am very stubborn and stuck with 6/7000 km OCI until recently too, my main fear being timing chain stretch due to soot contamination with longer drain intervals, always thought clean oil was the key to long timing chain life even if i have no doubt the engine will remain spotless. This is probably the only reason i've always preferred shorter drains with dino but now i feel like 13/15 000 km OCI with a good synthetic are still safe and i'm trying my best to limit waste of any kind to help my wallet as well as the planet. I'm still asking myself what's best for timing chains, clean cheap dino/semi vs dirtier high end 229.5 synthetic.
 
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I am very stubborn and stuck with 6/7000 km OCI until recently too, my main fear being timing chain stretch due to soot contamination with longer drain intervals, always thought clean oil was the key to long timing chain life even if i have no doubt the engine will remain spotless. This is probably the only reason i've always preferred shorter drains with dino but now i feel like 13/15 000 km OCI with a good synthetic are still safe and i'm trying my best to limit waste of any kind to help my wallet as well as the planet. I'm still asking myself what's best for timing chains, clean cheap dino/semi vs dirtier high end 229.5 synthetic.
In my 43 years of using M1 oils at 10K OCIs (miles) I have never had timing chains stretch (actually wear). I have put some 885K in the last 25 years on engines with OHCs that had chains, and never had a chain noise or any indication of wear.
 
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I don’t feel it adds any benefit really plus my cars don’t get driven a lot and I change the oil every 3000 miles or 3 months. Except my moms car we do 5000 or 5 months because it has to have synthetic.
Regular oil is full of sulfur. When a car is driven short distances and doesn't warm up enough to evaporate the condensate the water combines with the sulfur and makes sulfuric acid.
 
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