Synthetics and Extended Drain Intervals

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How many of you after being on this site for awhile feel more comfortable changing the oil a bit more often, rather than extending the drain intervals?

I've noticed over the years that "rarely" do we see good reports beyond 10k miles, even with good oils like Amsoil or Mobil 1.

I would guess that less than 20% of the UOA's beyond 15k miles look decent. Every now and then one will come thru and look good, but for the most part, they don't. Or are we just too picky with the numbers?

I think the norm on here has become 5-7.5k miles using any brand of oil, usually API SM conventional oils.

Maybe the new Amsoil Eao filters will help improve the results. With Amsoil the wear is usually good, but low TBN and viscosity seems to be shot around the 15k mile mark on average.
 
The problem with me is the time (12 months) comes up first and I always want to try a different oil. What can I say? I have the disease. It just manifests it's symptoms in different ways....or I just have the disease worse.....
 
I've reduced my drains from the blind 1-year/15-20k Amsoil fills I used to run to 1-year or 10k fills on PP 5w20 for both cars now. It's still long to the majority here, however.
 
I usually do the timeline interval as well. It usually gets changed every 2000-3000 miles. I know the oil can go longer,but I do ALOT of very short everyday trips (to and from work) and plus I live in a very dusty climate.
 
If it's dino I like to change it between 3-4k, because it usually takes 6 months for me to get that mileage. If i'm running synthetic, I change it at 5-7k or 1 year.
 
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the reason why there aren't extended drain intervals on here is because you guys spend more time on this site posting than behind the wheel in your car
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Yeah, with me, I have one car that I don't dare extend, the SAAB. One the other, the CR-V, I just get bored and worried with one oil in there over six months.
 
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the reason why there aren't extended drain intervals on here is because you guys spend more time on this site posting than behind the wheel in your car
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I know that's the case for me
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I'm almost as addicted if not more to this site as I am my car itself.
 
I have a 95 Toyota Camry with 2.2l 5SFE engine now with around 130000 miles.

I bought it with 90000 miles about 1.5 year ago I think.

The car has regular oil charge prior to my ownership. After I get the car, I charged to M1 SL and do 5000 miles oil charge. I feel fine with this even before coming to BITOG.

After reading more from this site, I do a 7500 miles oil charge last time, heck! The oil comes out so so so dark that I can't withstand! I will go back to 5000 miles, or maybe 6000 miles.

I don't do UOA, even if the oil is still ok to use maybe up to 10000 miles, I still won't do it. I can't withstand the oil so dark in my engine!
 
I know that's the case for me I'm almost as addicted if not more to this site as I am my car itself.


I`m right there with ya ThirdYe! This site IS addicting!
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Amsoil has some old literature that shows the measured wear in taxi cab engines. The least wear was in the "I am almost positive" 6,000 mile and 12,000 mile oil change intervals. The wear with a 60,000 mile oil change with a bypass filter was about the same as 3,000 mile petro oil changes . Keep in mind that this is an old test .I think Amsoil used a better than pao base oil then.
 
I would run redline 1 year 10,000 miles with out a second thought if some one would buy it for me. Even the Amsoil HDD or the diesel marine oil
 
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"I've noticed over the years that "rarely" do we see good reports beyond 10k miles, even with good oils like Amsoil or Mobil 1.

I would guess that less than 20% of the UOA's beyond 15k miles look decent. Every now and then one will come thru and look good, but for the most part, they don't. Or are we just too picky with the numbers?"
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I wonder that through all the observations on the UOA data, that one tends to adjusted one's point's of view for what stands as "good" or "bad"? From what little I have looked at in terms of making UOA comparisions, it just seems to me that other than the few cases where issues are staring at you point blank (antifreeze, leaded fuel or low visc = high pb, Si from ingestion), the numbers seeming as close as they tend to be, lead one to be more discriminating.

Just a though.

Take care.
 
I can't honestly say I'd ever be super comfortable running any oil for longer than 10,000 miles, although if the UOAs showed it was ok I would go as high as 15k but that would be absolutely it. The only way I'd ever go 25k between changes would be if I was driving 1000 miles a week (which will never happen)
 
Yesterday I had the dino in our 4 banger switched out for synthetic.

I had gone 8400 kms (5000 miles) in 4 months on dino and wasn't comfortable taking it much farther, even though the OLM said there was 26% oil life left.
 
I do 15,000 mile changes on my Honda with Mobil 1 ep. UOA at 11,000 looked very good. I do 10,000 mile changes on the Miata with mobil 1 0w-40. My last uoa on it was good and I went over by 2000 miles. I would never have believed I could do this 4 years ago when I found this site. Oils can go the distance now and why waste time under your car for nothing.
 
I don't feel comfortable going super extended drains...I'd like to see a lab wear test (like 4 ball wear) with fresh oil and oil that's been in a car for 15,000 miles and see what the results would be...


My brother bought into the 25,000 mile Amsoil hype...He had to get his motor on his (tahoe I think) rebuilt with only about 100,000 miles on it....Don't know all the possible variables that could've led to that...Could've been just a factory defect, perhaps he ran low on oil, maybe some other issue caused the problem unrelated to the oil itself...All possible variables that could've led to the problem....But oil is responsible for protecting the engine and he runs those long drain intervals and had to get the motor rebuilt...
 
You know Buster, with the sales now and then on group III synthetic oils lately...Pennzoil, Valvoline, Quaker State, etc...I have switched up a bit... I have been doing the Amsoil EaO filter and changing the oil(one of the above) every 5K. After 3 oil changes or 15K on the Eao. I start all over. I have been a die-hard Amsoil oil user for years and have just started to try my latest method since I have been a BITOGER.
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I typically do 15k/1 year intervals in N/A engines and 10k intervals in my Audi turbo with Amsoil. I've been doing this since 1978 and have yet to wear out a motor, or even have one get to the point where it was using much oil. I'd be very comfortable doing these kind of intervals without the benefit of oil analysis, given my past experience. I think you'd be very surprised on what's considered "normal" wear by powertrain engineers.

As for TBN retention, it's very non-linear. The TBN can stay in the 2-4 range for thousands of miles, depending on conditions.
 
Hmm, I just don't understand the 3k interval at all. In Europe the standard interval have been 8k/1yr since the 70s. There's no talk of engines wearing out.
Lately the intervals have been prolonged, some vehicles up to 30k miles. No reports of failures other than for vehicles that run low on oil (year long interval without checking the stick.) Some Audis are notorious oil-users and the longer interval doesn't work if you are more than a quart low.
So basically, you should be ok with 10k in any situation, 15k surely, 25k if the manual states that.
 
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