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How exactly does the Oil Life monitor calculate remaining oil life?

If I put in standard (dexos1 approved) syntheitc-blend oil, that would give me like 5000-7000miles per change, versus (dexos1 approved) Mobil 1 Extended performance full synthetic that guarantees 15,000miles/1yr per oil change, will the car calculate oil life differently?

Basically, is remaining oil life based solely on driving habits, or do the effects on engine operation of differnt oils factor in as well?

I have a 2011 ECO MT.
 

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It is strictly a cycle counter that weights the cycles based on temperature and engine load... It doesn't know if you've got $12/qt Motul or $1.99/qt Formula Shell in it, but it is calculating based on the minimum Dexos1 specification...

Mike
 

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Driving habits, at least at this level of OLM. It's also monitoring other engine parameters like crazy to help refine that number. It's going to give a higher mileage for a car driven mostly highway over a car driven mostly city due to fewer cold starts and more time at temperature.

If you want to run over the OLM's recommendations, get your oil analyzed. There's no substitute for knowing how a certain engine is faring on a particular oil other than analysis. That will say if the oil is loaded up with wear metals, how the additives in it are doing, and how much life is left in the oil. Cost is about $30-45, depending on how extensive the requested testing is.

15k miles per oil change on a turbocharged gasoline engine is a bit of a stretch. That's why one needs the oil analysis.
 

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...sitting un-driven and slow, city driving drastically reduce the OLM estimated miles duration.

...conversely, steady, highway milage seems to lengthen the OLM estimated miles duration.
 

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It could be like an older BMW, and simply wait for 2200 liters of fuel to be burned. Less fuel burned on highway driving = longer OCI, more fuel burned in city driving = shorter OCI.
 

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It could be like an older BMW, and simply wait for 2200 liters of fuel to be burned. Less fuel burned on highway driving = longer OCI, more fuel burned in city driving = shorter OCI.
Yeah... or how it actually works...

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V

It is strictly a cycle counter that weights the cycles based on temperature and engine load... It doesn't know if you've got $12/qt Motul or $1.99/qt Formula Shell in it, but it is calculating based on the minimum Dexos1 specification...

Mike
 

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What cycle exactly is it counting? Crank shaft revolutions? The salesman told me it was key turns, but sounds like salesman barf to me.
 

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Engine cycles, aka engine revolutions...

Mike
Engine revolutions is only a small part of it. Operating temperature, number of starting cycles, and distance driven all factors into it. In the last 600 miles, I've supposedly only used 5% of my oil life, yet I drive close to 100 miles per day. Far more revolutions than someone who only has a ten minute in-town commute, but their oil life meter will drop far more quickly.
 

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Engine revolutions is only a small part of it. Operating temperature, number of starting cycles, and distance driven all factors into it. In the last 600 miles, I've supposedly only used 5% of my oil life, yet I drive close to 100 miles per day. Far more revolutions than someone who only has a ten minute in-town commute, but their oil life meter will drop far more quickly.
He stated this earlier in the thread.
 

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He stated this earlier in the thread.
Yep...

It is strictly a cycle counter that weights the cycles based on temperature and engine load... It doesn't know if you've got $12/qt Motul or $1.99/qt Formula Shell in it, but it is calculating based on the minimum Dexos1 specification...

Mike
You don't have to look at EVERYTHING, if you can look at certain things that tell you what everything else is doing, and use much less processing power and data storage to do it...

You don't need to count starts if you weight cycles based on temperature... Cold starts are about the only reason that engine temperature would be 50F... Warm restarts are fine, because the oil still has a good film on everything... City driving, you are also in lower gears, so there will be more cycles, and you are accelerating at higher RPM, so there are a lot of cycles that are weighted heavier, due to higher load... Towing is harder on the oil, but the oil temperature will be higher, and the load is higher, so it weights those cycles more than low load cycles; as well as the fact that you're usually at higher RPM because of downshifting more, or being in a lower gear what you tow...

Mike
 

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Engine revolutions is only a small part of it. Operating temperature, number of starting cycles, and distance driven all factors into it. In the last 600 miles, I've supposedly only used 5% of my oil life, yet I drive close to 100 miles per day. Far more revolutions than someone who only has a ten minute in-town commute, but their oil life meter will drop far more quickly.
I saw different results. The oil from the factory lasted to 7500 miles (still had 22% left) but when I got it changed the life went back up to 100% and I notice that I'm only at 10k now but I have 65% left. I should be closer to 75ish.

I had them put in Pennzoil Platinum 5W-30 Full Synthetic which is on the dexos approved list

I also drive 100 miles each day just to work.
 

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You can make it 100% anytime you want to by pushing reset. In fact if you don't you will start off with whatever percentage you were at originally. My personal opinion is 3000 for regular and 5000 for synthetic or blend. Longterm costs you more money but I just don't like driving around with contaminated oil for half the year because an electric gauage says it is good. at 5K I am getting some pretty nasty oil out of my car. It certainly can't hurt to get the dirt out of your engine :)
 

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I'll trust the oil life monitor. I drive far too much to change my oil every 5k miles. Color has nothing to do with oil life. The oil can be black as night with lots of active additive left, or golden amber and used up. The only time color correlates with life is when it looks like milkshake.

The filter also gets more efficient as it loads up, to a point. These engines have a large filter for their size.
 

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You can make it 100% anytime you want to by pushing reset. In fact if you don't you will start off with whatever percentage you were at originally. My personal opinion is 3000 for regular and 5000 for synthetic or blend. Longterm costs you more money but I just don't like driving around with contaminated oil for half the year because an electric gauage says it is good. at 5K I am getting some pretty nasty oil out of my car. It certainly can't hurt to get the dirt out of your engine :)
Actually, long term, per an SAE study that came out several years ago, 90% of the wear that happens in an engine happens in the first 1000 miles after an oil change, before the new additives really get working... So by changing at 5k, instead of 10k, you're putting twice the wear on your engine...

:question:
Yes, nearly all filters get more efficient at filtration (not flow) as they load up... Even Brita water filters... The notable outlier in this is oiled foam filters, that use the oil to grab dirt... They don't get much worse, but don't get better, either...

Mike
 

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Gotcha, i'll still stick with 5K changes and risk it. I'll give you the first 1000 miles an engine is run but I have a hard time believing the rest of it. Although I guess a 100 clogged filter would filter better than a clean one, but I will still stick with removing the dirt and keeping my oil pressure up. Not disagreeing with you without more info, but seems like it is kind of silly. I just don't see dirty oil at 10-15K and a partially clogged filter being better than fresh oil and a clean filter. maybe I'm wrong, but I'll keep risking it at 5K, call me old fashioned :). I'll concede you can get better friction resistance in a used oil since it has gone through some heat cycles which will make zddp bond to the engine faster but that in no way effects how much dirt and contaminants are in your oil. Nex Gen is used FILTERED motor oil and is very good for that reason. But the assumption with that is that the oil is used and clean, not with thousands of miles of dirt and grime in it. Also do not discard the cleaning effect of fresh oil, alot of the increased wear in these studies could be attributed to the fresh oil flushing out the contaminants in the old oil. Viscosity isn't the only battle in oil wear, contamination and resistance to heat are also huge factors to engine wear. A good read is below.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1528239&page=2
 

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Gotcha, i'll still stick with 5K changes and risk it. I'll give you the first 1000 miles an engine is run but I have a hard time believing the rest of it. Although I guess a 100 clogged filter would filter better than a clean one, but I will still stick with removing the dirt and keeping my oil pressure up. Not disagreeing with you without more info, but seems like it is kind of silly. I just don't see dirty oil at 10-15K and a partially clogged filter being better than fresh oil and a clean filter. maybe I'm wrong, but I'll keep risking it at 5K, call me old fashioned :)
I read the whole test report when I was an SAE member, and there were a couple good summaries about it (this was probably 5 years ago, so this isn't new info), but in 5 minutes of Googling, I can't find it... Regardless, it said the current motor oils had long-lasting additive packages, but they now take heat and pressure to fully activate, which takes ~1k miles, which is why the wear is so bad in the first 1k after an oil change... This was backed up with something like 10k UOA...

He did say "to a point" for a reason... Depending on the engine, a filter doesn't restrict flow until it's ~60-75% clogged... Regardless, if your engine is in good shape, a filter will last 20k with no problem...

Mike
 

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After finding many good UOA's on BITOG for syns being run 8-10k miles, and having my own data supporting that 8-10k is an appropriate interval on full synthetic oil for a car driven mostly highway, I'll stick with the OLM. Add in the slightly better filtration of an in-use (and not full) filter, and there's no reason why not to follow the OLM.

Our Honda's manual specifically says to change the filter every second oil change. The OLM on that car recommends 10-11k change intervals. After 50k miles of following the OLM and using full syn oil from 10k miles on, the engine is spotless inside.
 
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