# Oil Change Interval Lengths for Synthetic



## BradHerr (Sep 29, 2013)

I am on Amsoil. I get the oil analyzed about every 13,000 miles. I am at about 30,000 miles on this oil. The last sample was still at level 1, which is the best rating. I change filters after a "good" sample reading. 


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## BradHerr (Sep 29, 2013)

The oil life monitor doesn't use the quality of the oil to determine the life. I have to reset mine when it starts giving the warnings. 


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## Merc6 (Jun 8, 2013)

BradHerr said:


> The oil life monitor doesn't use the quality of the oil to determine the life. I have to reset mine when it starts giving the warnings.
> 
> 
> Sent from AutoGuide.com Free App


Yes, either reset it or just clear the message upon start up and reset when you actually change it. If you have an active OnStar account a red X is marked on the miles whenever you reset it. It's apart of the online stats not shown in the mobile app.


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## diesel (Jun 8, 2013)

After getting several oil analyses done, I determined that 15K miles is a good interval. I basically reset the OLM and run through it twice before I change oil. Still zero noticeable oil consumption close to 200K miles.


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## diesel (Jun 8, 2013)

BradHerr said:


> I am on Amsoil. I get the oil analyzed about every 13,000 miles. I am at about 30,000 miles on this oil. The last sample was still at level 1, which is the best rating. I change filters after a "good" sample reading.
> 
> 
> Sent from AutoGuide.com Free App


Interesting. When I got my oil tested, the tests showed some abrasion after about 18K miles, that was why I backed down to 15K.

Here's where I posted details:

http://www.cruzetalk.com/forum/201-...ssion/48818-oil-testing-anayslis-diesels.html


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## starspangled6.0 (Apr 16, 2016)

Totally agree on the oil life indicator. It does provide a useful tool to see how you are driving over the past few thousand miles though. 

30k is definitely the longest I've heard of. I may just get it tested now and then see what they say. Would love to push it out that far, if the oil holds up.


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## MP81 (Jul 20, 2015)

I usually run my Mobil 1/AC Delco filter on the Cobalt to about 10,000 miles - but this being a diesel/direct injection, who knows. 

I've been wanting to switch to synthetic here for a bit, but haven't had the time to take care of changing the oil on this car myself (since I'll have to "learn" a new car), so I've been having the dealer do it - also because they do it for so cheap ($40 for Dexos2).


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## KpaxFAQ (Sep 1, 2013)

It depends is the best answer....With a lot of short tripping/idling/interrupted regens fuel dilution will get you. 

The people going with the big intervals are putting on real miles.

7,500mi is my max confirmed with UOA because of fuel dilution due to my driving habits.


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## XtremeRevolution (Jan 19, 2012)

diesel said:


> Interesting. When I got my oil tested, the tests showed some abrasion after about 18K miles, that was why I backed down to 15K.
> 
> Here's where I posted details:
> 
> http://www.cruzetalk.com/forum/201-...ssion/48818-oil-testing-anayslis-diesels.html


Bear in mind we have people going MUCH longer on diesel oils in other diesel engines than even 18k. I wonder if that analysis report was an outlier. Just saying; if the filtration is up to par, and the oil didn't oxidize, you should be good to go. 



KpaxFAQ said:


> It depends is the best answer....With a lot of short tripping/idling/interrupted regens fuel dilution will get you.
> 
> The people going with the big intervals are putting on real miles.
> 
> 7,500mi is my max confirmed with UOA because of fuel dilution due to my driving habits.


We see very high levels of fuel dilution in big rigs and other light diesel trucks. It never really leaves any cause for concern unless it gets above around 5%. As long as the wear metals are low, you won't have a problem. Your fuel dilution is likely setting in very early; I'll bet you'd see significant fuel dilution even at half that interval.


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## magnusson (Jun 15, 2014)

diesel said:


> Interesting. When I got my oil tested, the tests showed some abrasion after about 18K miles, that was why I backed down to 15K.
> 
> Here's where I posted details:
> 
> http://www.cruzetalk.com/forum/201-...ssion/48818-oil-testing-anayslis-diesels.html


Brad has his EGR blocked off if I remember correctly. His oil should last twice as long as those running EGR's.


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## IndyDiesel (May 24, 2015)

The oil capacity is around 4.5 quarts, to each his or her own, the engine costs around $5000 plus labor to replace. Amsoil for all I read is some of the very best oil on the market, I see little reason to run for more than 15k miles, the cost of sending oil in to determine how its doing is close to the cost of just replacing the oil. Filtration I would expect is very important, the AC Delco filter is probably designed for the oil life monitor not 15-30k miles. If I had the desire to drive that long on the oil I would be changing the filter more often. I don't currently drive enough miles in a given year to worry about extended intervals, 18k miles or so.


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## jblackburn (Apr 14, 2012)

IndyDiesel said:


> The oil capacity is around 4.5 quarts, to each his or her own, the engine costs around $5000 plus labor to replace. Amsoil for all I read is some of the very best oil on the market, I see little reason to run for more than 15k miles, the cost of sending oil in to determine how its doing is close to the cost of just replacing the oil. Filtration I would expect is very important, the AC Delco filter is probably designed for the oil life monitor not 15-30k miles. If I had the desire to drive that long on the oil I would be changing the filter more often. I don't currently drive enough miles in a given year to worry about extended intervals, 18k miles or so.


Not to mention that even their rated intervals are for 15K or *ONE YEAR*, whichever comes first.


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## cruze01 (Mar 25, 2011)

starspangled6.0 said:


> Totally agree on the oil life indicator. It does provide a useful tool to see how you are driving over the past few thousand miles though.
> 
> 30k is definitely the longest I've heard of. I may just get it tested now and then see what they say. Would love to push it out that far, if the oil holds up.


Why? Oil changes are cheap! About as cheap as taking a sample and sending it off. Good insurance in IMO and you dont have to argue with GM about a 30k OCI if something goes wrong....


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## BradHerr (Sep 29, 2013)

cruze01 said:


> Why? Oil changes are cheap! About as cheap as taking a sample and sending it off. Good insurance in IMO and you dont have to argue with GM about a 30k OCI if something goes wrong....


There is no real advantage to what I am doing. I still go to the dealer every 3 months for filter changes, oil sample and tire rotations that are about the same price if I had the oil changed. I also have to pay to send the sample in. There is no cost or time savings in my technique. I just enjoy doing it this way. 

Like I've shown before, the emissions delete is not a cost effective modification either. It was going to take an absurd amount of miles to save enough in fuel costs to break even on the cost of the mod. 

Somethings I do just to make me happy and not for any other reason. 


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## diesel (Jun 8, 2013)

cruze01 said:


> Why? Oil changes are cheap! About as cheap as taking a sample and sending it off. Good insurance in IMO and you dont have to argue with GM about a 30k OCI if something goes wrong....


They are not that cheap in the diesel.


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## IndyDiesel (May 24, 2015)

diesel said:


> They are not that cheap in the diesel.


To do it yourself is appx $50-60, at my Chevy dealer $75-90, I will probably just do my own.


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## starspangled6.0 (Apr 16, 2016)

I'd rather do it once a year than twice or three times. Don't get me wrong-I love working on my Cruze- but if analysis shows I can push my OCI to 15,000 or 20,000 miles, I definitely will. 2 oil changes saved = several tanks of diesel, or a cheap air intake, etc.


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## oilburner (Jun 13, 2013)

IndyDiesel said:


> The oil capacity is around 4.5 quarts, to each his or her own, the engine costs around $5000 plus labor to replace. Amsoil for all I read is some of the very best oil on the market, I see little reason to run for more than 15k miles, the cost of sending oil in to determine how its doing is close to the cost of just replacing the oil. Filtration I would expect is very important, the AC Delco filter is probably designed for the oil life monitor not 15-30k miles. If I had the desire to drive that long on the oil I would be changing the filter more often. I don't currently drive enough miles in a given year to worry about extended intervals, 18k miles or so.


bingo!!! exactly........oil change is cheap maintenance.


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## MP81 (Jul 20, 2015)

IndyDiesel said:


> To do it yourself is appx $50-60, at my Chevy dealer $75-90, I will probably just do my own.


Our dealer does CTD oil changes for $40, which is what has made it hard for me to pick out a synthetic to do myself - too **** convenient and cheap (and I already have three other cars I do the oil changes on myself).


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## IndyDiesel (May 24, 2015)

MP81 said:


> Our dealer does CTD oil changes for $40, which is what has made it hard for me to pick out a synthetic to do myself - too **** convenient and cheap (and I already have three other cars I do the oil changes on myself).


What oil are they using?


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## MP81 (Jul 20, 2015)

IndyDiesel said:


> What oil are they using?


Dexos2.

Listed on the invoice.


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## XtremeRevolution (Jan 19, 2012)

cruze01 said:


> Why? Oil changes are cheap! About as cheap as taking a sample and sending it off. Good insurance in IMO and you dont have to argue with GM about a 30k OCI if something goes wrong....


Sending oil samples has the added advantage of showing you how the engine is operating and allowing you track or find problems before they show up. Oil analysis reports are cheaper than oil changes. In your own words, good insurance, IMO. 

I'd never tell GM at what interval I change my oil. I had a long back and forth e-mail with a warranty representative a year or two ago on this subject and despite my very clearly worded questions, he refused to state that GM would void a warranty simply due to the drain interval alone. I'd just tell them I changed it according to the oil life monitor with oil I bought from a buddy for cash because he works at an auto store and gets it cheap. Otherwise, you're at the mercy of sales advisers that are generally ignorant on the subject of drain intervals and will give you a deer in the headlights look if you show them an oil analysis report. 



MP81 said:


> Our dealer does CTD oil changes for $40, which is what has made it hard for me to pick out a synthetic to do myself - too **** convenient and cheap (and I already have three other cars I do the oil changes on myself).


With that many cars, (shameless plug coming), AMSOIL makes a lot of sense. Once a year oil changes, and repeated oil analysis reports have proven the oil can do it. It's awfully convenient when you have more than one vehicle to worry about (I have three, and various lawn equipment as well). It takes just as long to drive to the dealer, get an oil change, and come back as it does to change it yourself (if not more), and you know you're using a product that's much better than the stuff GM puts in these cars. Admittedly not as big of a deal in the diesel, which is much easier on oil than the 1.4T, but still a difference nonetheless.


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## IndyDiesel (May 24, 2015)

With all due respect to Extreme, I think having actual records of oil changes are very important. If done at Chevrolet dealer you will never be asked to produce records in the very rare event you have an engine failure of some sort. For those that want to use any oil with extended change intervals while under warranty I think you may be doing it is possible you are giving GM or any manufacture a reason to not honor power train warranty. After warranty has expired I see really no reason to keep receipts and all other than maybe resale value to a future buyer. I know I will get blow back on my view, hey wont be the first time. I will probably do my own changes after my last free one, but maybe not, haven't decided yet.


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## XtremeRevolution (Jan 19, 2012)

IndyDiesel said:


> With all due respect to Extreme, I think having actual records of oil changes are very important. If done at Chevrolet dealer you will never be asked to produce records in the very rare event you have an engine failure of some sort. For those that want to use any oil with extended change intervals while under warranty I think you may be doing it is possible you are giving GM or any manufacture a reason to not honor power train warranty. After warranty has expired I see really no reason to keep receipts and all other than maybe resale value to a future buyer. I know I will get blow back on my view, hey wont be the first time. I will probably do my own changes after my last free one, but maybe not, haven't decided yet.


I think having actual records is important as well, but a dealer cannot make your warranty contingent on your ability to produce those records. They cannot say "we need to see what oil you used or we will void your warranty." As you noted, in the very rare even that you have an engine failure of some sort, but if I may clarify, an engine failure that is related to lubrication that shows clear and obvious signs that an oil failed to do its job. 

It wouldn't be GM refusing to honor the warranty, but the ignorant dealer, and there is a valid case to be made for not wanting to go through that hassle, especially with a vehicle crippled by a plethora of emissions control devices. I get that, but I also know that you can double your interval and run one oil analysis every time for the same cost as running OEM intervals, so in the event that your dealer does ask for documentation, you can provide the trending oil analysis reports. 

I'm not giving you blow back; your view has valid points.


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## IndyDiesel (May 24, 2015)

I guess I will state my position in a slightly different manner. If in the terrible position of having a engine failure, I would personally prefer to have detailed records to support my position that I did the necessary maintenance that should have prevented the failure and not give any manufacture wiggle room to deny my claim. I don't want to be gamble that by not having good records to have a possible deny of claims. I have driven several hundred thousand miles and only had one engine failure, ironically in a 1981 Buick Diesel, go figure, the engine locked up, it was a faulty design and not difficult for GM to understand they had a problem, it was out of warranty and they replaced the engine, I paid or my dad paid the labor, I was in college.


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## starspangled6.0 (Apr 16, 2016)

I think one question that begs to be asked is this: Do we actually have access to any kind of record that shows that oil was the direct cause of an engine failure? I think it's safe to say that we all know if you run no oil or too low of oil, the engine will fail as a direct result, but in my meager 9 years of driving and maintaining cars, personally and professionally, I've never came across such a case where Billy-Bob bought O'Reilly brand oil and it caused his beleaguered GM 3600 V6 to seize up.


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## diesel (Jun 8, 2013)

I have heard of cases where people were able to provide documentation of oil changes and still had warranty claims denied. This was related to the Toyota engine sludge issues. So, having records doesn't guarantee you'll be covered.


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## justin13703 (May 2, 2016)

diesel said:


> I have heard of cases where people were able to provide documentation of oil changes and still had warranty claims denied. This was related to the Toyota engine sludge issues. So, having records doesn't guarantee you'll be covered.


Toyota is notorious for being a bunch of assholes as far as warranty goes. They will screw you with a smile on their face. They screwed me BAD on the last Toyota I had. Needless to say, that will be the last Toyota I will ever own. Most American carmakers are not like this. Toyota just doesn't give a **** about you once they have your money and won't even try to make anything right.


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## XtremeRevolution (Jan 19, 2012)

justin13703 said:


> Toyota is notorious for being a bunch of assholes as far as warranty goes. They will screw you with a smile on their face. They screwed me BAD on the last Toyota I had. Needless to say, that will be the last Toyota I will ever own. Most American carmakers are not like this. Toyota just doesn't give a **** about you once they have your money and won't even try to make anything right.


Subaru is not much better either. Just another reason I've resorted to purchasing used cars that are just barely out of their warranty period from now on.


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## IndyDiesel (May 24, 2015)

I have been pretty lucky, never really had very many warranty issues to date. I have driven mostly GM and some Fords. I kinda think the warranty is almost more of a peace of mind sales tool vs something that is used on a regular basis, or at least that has been my experience, maybe I have just been lucky.


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## XtremeRevolution (Jan 19, 2012)

IndyDiesel said:


> I have been pretty lucky, never really had very many warranty issues to date. I have driven mostly GM and some Fords. I kinda think the warranty is almost more of a peace of mind sales tool vs something that is used on a regular basis, or at least that has been my experience, maybe I have just been lucky.


I think you've had some decent luck. Under warranty on my Cruze, GM replaced:

- flywheel
- intake manifold
- valve cover
- front shocks
- oil pan seal
- washer spray nozzles
- HVAC box (due to odor when running heat)

The HVAC box smell may have eventually gone away, the washer spray nozzles were cheap, but the oil pan seal is a PITA job that requires lowering the exhaust, the intake manifold is a $350 part from GM, and the flywheel requires dropping the transmission out of the car.


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## IndyDiesel (May 24, 2015)

XtremeRevolution said:


> I think you've had some decent luck. Under warranty on my Cruze, GM replaced:
> 
> - flywheel
> - intake manifold
> ...


Had two Cruzes, 14 Eco Manual, which at 5000 miles I had a squeaky Clutch in the Pedal Assembly, they removed that and replaced some bushing, drove that car 22k miles, driven 15 Diesel for 18k miles and zero issues so far. So 40k miles between two, one warranty issue, I think that is pretty good. Like many on the Forum, I pay close attention to my cars, if something doesn't act right I get it fixed whether in warranty or not.


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## XtremeRevolution (Jan 19, 2012)

My friend Brad Herman, who I believe is also a member here, has been taking trending oil analysis reports of his run with AMSOIL 5W-30 European Formula engine oil. 

How long can AMSOIL 5W-30 European Formula engine oil go in a Cruze Turbo Diesel?


According to Polaris Labs, an ASTM Certified lab, approximately 40,000 miles.


Last sample had 32,921 miles on it and Polaris Labs recommended another 7,000 miles.


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## MP81 (Jul 20, 2015)

What kind of filter is that using, and how long can the filter be used?


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## BradHerr (Sep 29, 2013)

I am using the GM filter. I change the filter every 10,000-13,000 miles. 


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## BradHerr (Sep 29, 2013)

MP81 said:


> What kind of filter is that using, and how long can the filter be used?


I am using the GM filter. I change the filter every 10,000-13,000 miles. 


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## IndyDiesel (May 24, 2015)

That's putting a lot of trust in someone being able to evaluate the oil. Pretty cool I guess. I couldn't do that but interesting that others can. The part I find so interesting is the capacity of this little diesel engine for the oil is modest at 4.5 quarts. That's amazing an oil can meet specs for that long given that capacity.


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## IndyDiesel (May 24, 2015)

BradHerr said:


> I am using the GM filter. I change the filter every 10,000-13,000 miles.
> 
> 
> Sent from AutoGuide.com Free App


I haven't changed my oil on CTD yet, I assume you may have to add a small amount of oil when just changing the filter between changes?


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## BradHerr (Sep 29, 2013)

IndyDiesel said:


> I haven't changed my oil on CTD yet, I assume you may have to add a small amount of oil when just changing the filter between changes?


I haven't had to add oil at every filter change. I will run it as long as it is in the operating range on the dipstick. 

I have been pulling a sample before each filter change.

I just add oil when it gets a full quart low. 


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## IndyDiesel (May 24, 2015)

BradHerr said:


> I haven't had to add oil at every filter change. I will run it as long as it is in the operating range on the dipstick.
> 
> I have been pulling a sample before each filter change.
> 
> ...


Hope your engine never fails, but if the car quits at 500K or something like that, would be very interesting to tear the engine down and see the internals of engine and see how clean it is and how the tolerances are, etc. Or if it has an impact on turbos and the like... Happy Motoring!


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## BradHerr (Sep 29, 2013)

IndyDiesel said:


> Hope your engine never fails, but if the car quits at 500K or something like that, would be very interesting to tear the engine down and see the internals of engine and see how clean it is and how the tolerances are, etc. Or if it has an impact on turbos and the like... Happy Motoring!


I agree. But, It is hard to do side-by-side comparisons to see if my technique netted different results to someone using a shorter drain interval. I would like to see what it looks like though. We'll see how it goes. 


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## XtremeRevolution (Jan 19, 2012)

IndyDiesel said:


> That's putting a lot of trust in someone being able to evaluate the oil. Pretty cool I guess. I couldn't do that but interesting that others can. The part I find so interesting is the capacity of this little diesel engine for the oil is modest at 4.5 quarts. That's amazing an oil can meet specs for that long given that capacity.


We had another AMSOIL dealer send out duplicates of tests for a company to the same lab and record which they marked. These guys were sending out a hundred or more analysis reports. The consistency came back perfect. Polaris Labs is a very trustworthy and reliable lubricant testing facility. I'll find the post where the guy explained the testing they did. 

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## XtremeRevolution (Jan 19, 2012)

Here, I found it. 



> Several years ago I was working on a large fuel additive study with a food distribution company (not an AMSOIL fuel additive). We decided to deploy oil analysis to better baseline all of their power units (120+) and several refers. We had no history with the product and didn't know if it may get into the sump and damange the lubricant or otherwise change drain interval. Before collecting 100's of samples over months and months I decided that we needed to go above and beyond to ensure that we could hang our hat on this data. A tech and I randomly picked a candidate unit and collected a few quarts from the sump, blended it in a nice new container and sealed it with a very descriptive label (CRITICAL OIL SAMPLE HAND MAY BE CUT OFF IF YOU DISTURB IT). From that point I split it into 8 individual sample bottles and blind coded the labels and equipment descriptions so they looked no different than the others, but we could identify them later.
> 
> I sent 3 to Polaris labs with our first batch of 45 tests. All analytics were well within the stated measurement error for the methods and displayed very good autocorrelation. We made Individual and Moving Range Control Charts for each type of test from this data. It was a beast of a study because we also did extensive statistics to trend each result for each type of Engine class too. There was extensive load leveling, route planning, idle time monitoring, randomly assigned drivers (that p!ssed them off)...it was a bear to manage. During each sample period we would send one of the 5 remaining control jars in- blind coded to be analyzed along with our other engine sump samples. This was a 9 month long study so there was plenty of opportunity for error to be introduced. After the final sampling period we looked back at the data and saw no trending or unacceptable deviation within our blind controls. At that point we pretty much decided that Polaris had a solid process in place and that we could trust their results.


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## MP81 (Jul 20, 2015)

So it sounds feasible that I could probably run the AMSOIL 5W-30 synthetic to 15k, along with one filter. I don't have an issue not pushing the oil that far, but if I'm changing the filter, I might as well be doing the full oil change. I'd imagine it should last to 15k without issue.


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## BradHerr (Sep 29, 2013)

MP81 said:


> So it sounds feasible that I could probably run the AMSOIL 5W-30 synthetic to 15k, along with one filter. I don't have an issue not pushing the oil that far, but if I'm changing the filter, I might as well be doing the full oil change. I'd imagine it should last to 15k without issue.


I changed my filter at 13,000 miles and it showed no signs of deterioration. I was worried about it collapsing, but from limited sampling, I feel the stock filter should be able to handle 15,000 miles. 


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## MP81 (Jul 20, 2015)

BradHerr said:


> I changed my filter at 13,000 miles and it showed no signs of deterioration. I was worried about it collapsing, but from limited sampling, I feel the stock filter should be able to handle 15,000 miles.


Cool. The newer cartridge filters seem to retain a good amount of rigidity, even when swapped out. I've been running my Cobalt to 10k for years, and that filter (also a cartridge) always look good, so it's good to see it applies here too.


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## diesel (Jun 8, 2013)

This is all making me think that my 15-16K intervals may be too short.


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## XtremeRevolution (Jan 19, 2012)

diesel said:


> This is all making me think that my 15-16K intervals may be too short.


To be fair, I think it's worth reminding that Brad's driving was 90% highway and he has an emissions delete, both of which help significantly. 

That said, I'd evaluate using an analysis from Polaris Labs so you can see oxidation at your intervals, as that was the only relevant thing flagged on his.


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## IndyDiesel (May 24, 2015)

diesel said:


> This is all making me think that my 15-16K intervals may be too short.


The true test really is longevity without engine or turbo issues, not a report from a company testing the oil. Time and miles we should know more. I find it encouraging tho that oil can protect for that long.


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## IndyDiesel (May 24, 2015)

XtremeRevolution said:


> To be fair, I think it's worth reminding that Brad's driving was 90% highway and he has an emissions delete, both of which help significantly.
> 
> That said, I'd evaluate using an analysis from Polaris Labs so you can see oxidation at your intervals, as that was the only relevant thing flagged on his.


Can you elaborate on his higher oxidation results and what that means to a consumer, I don't have enough knowledge what that means per say. I assumed it may mean moisture of some sort, but honestly just a guess on my part. Thx


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## XtremeRevolution (Jan 19, 2012)

IndyDiesel said:


> Can you elaborate on his higher oxidation results and what that means to a consumer, I don't have enough knowledge what that means per say. I assumed it may mean moisture of some sort, but honestly just a guess on my part. Thx


Oxidation is the reaction between lubricating hydrocarbons and the oxygen in the air. Oxidation occurs due to time and due to heat. Severe oxidation is what we refer to as sludge. Polaris Labs has triggers for certain oils for what oxidation levels are deemed acceptable before it should be changed. Oxidation has a thickening effect, which in Brad's analysis report appears to be negated by some fuel dilution. 

Side note: ester based oils typically read oxidation high even when brand new due to the testing method. You'll see oxidation anywhere between 45 and 100, so the metric used there is the oxidation increase, not the base oxidation.


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## Badbird (May 13, 2017)

Wow, I can't imagine going 20k or 30k on the same oil but that's just me....I have a family member that does it with every vehicle he buys. I currently use Amsoil with an AC Delco or Wix filter and change at 7k to 8k and as someone said above, if I'm going to change the filter I may as well replace the oil too. After mid July when my bumper to bumper is over, I'll install my deletes and will increase my intervals to 10k or once a year, whichever comes first.


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## Diesel Dan (May 18, 2013)

There was a guy over at TDR (dodge diesel site) who went 200k+ on amsoil with a dual bypass kit. Fuel contamination from a bad lift pump is what made the change necessary.


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## BDCCruze (Jul 12, 2017)

BradHerr said:


> I am on Amsoil. I get the oil analyzed about every 13,000 miles. I am at about 30,000 miles on this oil. The last sample was still at level 1, which is the best rating. I change filters after a "good" sample reading.


Do you get free oil analysis? If not, $30-40 for the analysis is about the cost to change your oil. I would think the money is better spent on new oil if the cost is the same.


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## XtremeRevolution (Jan 19, 2012)

BDCCruze said:


> Do you get free oil analysis? If not, $30-40 for the analysis is about the cost to change your oil. I would think the money is better spent on new oil if the cost is the same.


You can get dexos2 synthetic and filter for $30?

You're assuming oil analysis has no other value other than validating extended drain intervals.

He spends $30 every 13k miles for oil analysis. Go ahead and run the math for me to show how much it would cost to change oil at OEM intervals by comparison. Note that he's now at over 40k miles on the same oil...

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## BDCCruze (Jul 12, 2017)

XtremeRevolution said:


> You can get dexos2 synthetic and filter for $30?
> 
> You're assuming oil analysis has no other value other than validating extended drain intervals.
> 
> ...


You can get 5qts of 5w-30 Dexos2 and a filter for about $35 (buy in bulk to save shipping on filters).

So, even if you stretch out an oil change and go through 2 100% cycles (about 15,000 miles) on the DIC, you are spending $35 for an oil change compared to spending $30 to just have the oil analyzed. Plus consider an analysis takes a bit of the oil so you may have to add more in after 2 analysis (buying at least a quart, which is $5-7).

So you are right, you can save a couple dollars by doing the analysis only. I would rather take the new oil and spend $5 more. To each his own.


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## XtremeRevolution (Jan 19, 2012)

He has a preferred customer account with AMSOIL. I can't advertise the pricing publicly but it's about $30 for the analysis, so an oil change costs more than an analysis. 

Again, you missed the fact that he has not changed the oil for 40,000 miles. He has ONLY done oil analysis and filter changes for that period (and topping off oil), which is why he does oil analysis every 13,000-15,000 miles. Otherwise, you'd only do the oil analysis once at 15,000 miles, verify that it's good, and continue changing oil every 15,000 miles thereafter knowing the oil is fine at that interval. Note, I am not referring to GM's cheap semi-synthetic here, to be clear. I am referring only to oils that are actually capable of those intervals. 

An analysis takes approximately 3-4oz of oil from the system. A quart is 32oz, so at worst, you're taking 1/8 of a quart. If you even notice it on the dipstick, I'll be surprised. 

Oil analysis tells you more than just the condition of the oil. It can clue you into other problems that allow you to investigate root causes before they become catastrophic. While oil analysis is limited in scope, it does give you a glimpse of what's happening inside your engine. Bad injector? You'll see the fuel dilution. Coolant issue? You'll see traces in the oil analysis. EGR issue? You'll see elevated soot levels. Those are just a few of the potential issues you can identify early on with an oil analysis report. 

A jug of *good* dexos2 synthetic will run you $35-$40, excluding filter.


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