# Oil Change Interval...



## McNeo (Dec 17, 2013)

3k miles was beat into me in school, too. Even though the newer synthetic oil may last longer, the filter may not. Not to mention, changing your oil is only half of whats happens when you change your oil - along with changing the filter, of course, you're also letting any other contaminants out of the system by draining it.

I've been going about 5,000 miles on my 1.4T, running Mobil1 Full Synthetic 5w30 and a Wix filter.


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## Vetterin (Mar 27, 2011)

I've been changing mine at 6000 - 6500 miles (DIC showing 20% - 30%) using only QS Ultimate. I have had no oil loss between changes and presently have 60,000 miles.


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## spacedout (Dec 7, 2010)

I change my oil once every 4 months or 7500 miles with mobil 1. March, July and November, that way I have fresh oil for spring, when the hottest part of the summer starts and before winter sets in.


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## GRIMland (Jun 1, 2014)

I've always done the 3 months 3k miles for regular oil and 5 months 5k miles for full synthetic oils. For the motorcyles it's once a year after getting it out of storage in the spring. I never put more than 1,000 miles on them a year anyway

I also like spacedout's idea of new oil in spring and before winter. That's about how I time mine too.


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## jblackburn (Apr 14, 2012)

> Chrysler 2.7L, you can change the oil religously on that engine and when you pull a valve cover, it will be sooooooooooooooooooo sludged up, it will look like you NEVER changed it, or the VW/Audi 1.8T, and some Toyota engines etc...


Those are all engines that suffered from poor design and are commonly referred to as "sludge pumps". I had the cam cover off a Toyota 3.0L, and it was quite the mess inside.

Get rid of the Dexos-1 blend, use a _*good*_ off-the-shelf synthetic oil, and stick to 6000-7500 mi oil changes or ~8 months, whichever comes first.

Pick one from this list:
http://www.cruzetalk.com/forum/10-powertrain/41385-tiered-oils-list-understanding-synthetics.html


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## XtremeRevolution (Jan 19, 2012)

jpr0204 said:


> Afternoon All,
> 
> Let me begin by saying "I know, I know..." this is a very sensative topic that can vary GREATLY by opinion.
> 
> ...





McNeo said:


> 3k miles was beat into me in school, too. Even though the newer synthetic oil may last longer, the filter may not. Not to mention, changing your oil is only half of whats happens when you change your oil - along with changing the filter, of course, you're also letting any other contaminants out of the system by draining it.
> 
> I've been going about 5,000 miles on my 1.4T, running Mobil1 Full Synthetic 5w30 and a Wix filter.


I'm going to respond to both of these. 

It's called oxidation. It occurs with mileage, time, and heat. Some engines are more susceptible to it than others. Some oils have a more robust antioxidant package. Making blanket statements about lubrication on a wide array of engines is not going to help anyone.

3k miles or 3 months is a waste of money unless you are on cheap dino oil. This engine requires an oil that meets dexos1 specifications. 

This topic varies greatly by opinion because very few people have even an elementary knowledge of engine oil formulation. This is further compounded by the fact that oils people used to trust are constantly being re-formulated to appease stock holders. Our oil analysis has shown that the dexos1 oil is good for up to 6k miles. I would add, or 6 months. 5k miles would be fine as well without turning this into a waste of money. 7500 miles is the point at which the additive package will be effectively depleted. 

Our filters are good for 6 months or about 7500-10000 miles. The problem is not so much clogging as it is media degradation, hence the 6 months. I wouldn't push it more than 9 months if you absolutely had to.

Synthetic oils can go anywhere from 7500 to 15000 miles in the 1.4L engine, with the actual mileage depending on the formulation. A filter change half way through an extended drain would solve that problem for $5-$7 and 5 minutes of your time. 

As you can tell, these are not opinions. This is information provided from oil analysis and my studies toward an STLE Certified Lubrication Specialist certification. Lubrication is a science, and when we have the means to test our oils for $25-$30, there isn't any room for speculation or guessing. 

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## q2bruiser (Jun 8, 2014)

If you take the time and money to have your oil analyzed at different mileage intervals, you will find the wear metals are often higher in the first 1000 miles. This is quite common across different vehicle manufacturers, oil brands, dino or synthetic. The point is, due to modern oil formulations, their cleaning and protection properties, and their tendency to bed in after initial cleansing, you may actually be wearing your engine more than if you ran oil to spec.


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## Blue Angel (Feb 18, 2011)

My personal preference WRT oil filters is to change them twice per OCI since they are so cheap. This is surely overkill, especially when using a good oil, but on the off chance there could be a mechanical failure of the media structure due to pressure difference across the filter due to loading, this will greatly reduce that risk.

WRT oil and OCI, pick a good consumer brand synthetic and run it for 7500 miles, or stick with regular Dexos1 oils and change them out at 5000 miles. Either is a very safe bet for a long lasting healthy engine.

Take a peek under the oil fill cap every now and then and make sure your engine bits are staying a nice clean silver color. If they start to turn yellow or orange, try a different brand of oil. Don't worry about black oil... dirty oil is doing its job of keeping contaminants suspended.

Also make sure to get the engine nice and hot on a regular basis. This will help burn off fuel and moisture, both of which reduce an oils lifespan.


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## jpr0204 (Jul 23, 2014)

Wow! All great feedback here. It looks like everyone goes by what they feel comfortable with in regards to oci's.

I have to admit that Xtreme Reveloution schooled me on oil breakdown, formulation, and analysis.  We all hear about it, we know that different weights exsist, we know it looses additive package over time, etc... But when put into perspective such as how it was put above, Definately gives a clearer understanding. what an excellent post!


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## CruzeEcoBlueTopaz (Jan 5, 2012)

Here is an example of the silver bits after 225k miles of using a quality oil.










Link to a slightly larger image http://www.cruzetalk.com/forum/memb...um2145-pictures-picture100010-silver-bits.jpg


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## money_man (Feb 25, 2014)

CruzeEcoBlueTopaz said:


> Here is an example of the silver bits after 225k miles of using a quality oil.
> 
> 
> 
> ...


And what are you using?

Also xtreme talked about the dexos 1 going for 7500miles but what about the dexos 2 in the diesels?


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## Rocco611 (Jan 19, 2013)

De xos is a GM licensed standard, there are now several oils out there that state on he back of the bottle that they meet or exceed the dexos standard,but don't sport the dexos logo they cost a little less and don't have to pay license fees to GM. Im using PartsPlus 5-30 synthetic, it exceeds the standard and is a bit cheaper. had oil analysis done at 6500 miles , oil tested fine. rockauto has a great price on oem oil filters. I am all for getting most out of expensive motor oils and conserving resources


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## XtremeRevolution (Jan 19, 2012)

CruzeEcoBlueTopaz said:


> Here is an example of the silver bits after 225k miles of using a quality oil.
> 
> 
> 
> ...





money_man said:


> And what are you using?
> 
> Also xtreme talked about the dexos 1 going for 7500miles but what about the dexos 2 in the diesels?


7500 miles is the point at which the additive package is depleted. I certainly do not recommend going that far. I wouldn't go past 6000 miles on the GM oil. The dexos 2 oil is an entirely different ball game because we are talking about a diesel engine, where drain intervals are very different. Drain intervals in diesel engines are dictated more by soot levels than total acidity. With bypass filtration, I've read of people going over 200k miles without draining the oil, topping off only when replacing filters to replenish additives.


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## CruzeEcoBlueTopaz (Jan 5, 2012)

Keep in mind this is my first new vehicle so within the past 2-3 years I just recently started to care about maintence and im still learning. With that being said I reget using the ac delco syn blend oil for the first 1 year and 100k miles replacing the oil every 5-6k miles. Since then I have graduated to m1 ep replacing the oil every 6k miles. It is a cost effective oil for me because of how often I replace the oil which is every 3-4 weeks. I will stay with it for the life of the cruze. My next new vehicle purchase I will invest in a higher quality group 4 " real " synthetic oil.


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## XtremeRevolution (Jan 19, 2012)

CruzeEcoBlueTopaz said:


> Keep in mind this is my first new vehicle so within the past 2-3 years I just recently started to care about maintence and im still learning. With that being said I reget using the ac delco syn blend oil for the first 1 year and 100k miles replacing the oil every 5-6k miles. Since then I have graduated to m1 ep replacing the oil every 6k miles. It is a cost effective oil for me because of how often I replace the oil which is every 3-4 weeks. I will stay with it for the life of the cruze. My next new vehicle purchase I will invest in a higher quality group 4 " real " synthetic oil.


With your driving conditions and how often you have to change oil, an oil analysis would be very beneficial. I have no doubt that you can extend that another 2k miles safely on even the standard Mobil 1. The Oil Analyzers Inc. report tests for TAN and TBN as well as the typical wear metals, additives, viscosity, and fuel contamination. You would make up the cost of the analysis very quickly. 

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## Burtess (Apr 7, 2011)

For the price of a decent and approved synthetic and a filter why push the change interval? In Canada on sale you're talking less than $40 and in the US probably less than $30. 

I changed mine every 5-6000 miles with QS Ultimately Durability and the engine is good.... To bad the rest of the car is falling apart around it lol....

Burt


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## money_man (Feb 25, 2014)

XtremeRevolution said:


> 7500 miles is the point at which the additive package is depleted. I certainly do not recommend going that far. I wouldn't go past 6000 miles on the GM oil. The dexos 2 oil is an entirely different ball game because we are talking about a diesel engine, where drain intervals are very different. Drain intervals in diesel engines are dictated more by soot levels than total acidity. With bypass filtration, I've read of people going over 200k miles without draining the oil, topping off only when replacing filters to replenish additives.


So 6000-7500 miles in diesel probably isn't so bad


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## XtremeRevolution (Jan 19, 2012)

Burtess said:


> For the price of a decent and approved synthetic and a filter why push the change interval? In Canada on sale you're talking less than $40 and in the US probably less than $30.
> 
> I changed mine every 5-6000 miles with QS Ultimately Durability and the engine is good.... To bad the rest of the car is falling apart around it lol....
> 
> Burt


It's not about pushing the change interval. It's about getting the most value out of the money you spent. If I have a synthetic that can go 10k miles, why should I go only 5-6k miles on it? 

QSUD just went through a bad formulation change in Q1 of this year. NOACK volatility went up from a previous 8.8% to 12.3%. DEXOS1 minimum is 13% just to put that into perspective. 



money_man said:


> So 6000-7500 miles in diesel probably isn't so bad


Not at all. Passenger diesels are not very hard on oil. Oxidation is probably your biggest problem. 

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## money_man (Feb 25, 2014)

Win!!!


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## Burtess (Apr 7, 2011)

XtremeRevolution said:


> It's not about pushing the change interval. It's about getting the most value out of the money you spent. If I have a synthetic that can go 10k miles, why should I go only 5-6k miles on it?
> 
> QSUD just went through a bad formulation change in Q1 of this year. NOACK volatility went up from a previous 8.8% to 12.3%. DEXOS1 minimum is 13% just to put that into perspective.
> 
> ...


For an extra $30 per year to make fully sure that oil is still doing its job is a no brainer to me, especially if the manufacturers are reformulating apparently for the worse without putting it on the bottle! I would rather do that than walk a thin line of a protected or not engine by trying to squeeze the last percent from my oil.

Burt


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## Blue Angel (Feb 18, 2011)

A member like CEBT is a prime example of someone who would really benefit from a higher quality oil's ability to go longer between OCIs. He has 225k miles on his Cruze already and changes his oil on a very regular basis. An oil analysis program for him would make sense even on his current Cruze as he is using the oil in near perfect conditions. IF a UOA was implemented showing him he could double his mileage between OCIs (not an unrealistic guess based on his driving), he would recoup any added costs almost immediately, and be saving significant money as well.

Some like to push limits just to see what's possible with little financial motivation at all, and others will do it for the money. The average driver may not get their money back as quickly, but a good plan will usually put you back in the black after some reasonable time period. Many people change their oil too soon, as discussed earlier in the thread.


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## money_man (Feb 25, 2014)

Here's a question. Will Blackstone labs do testing on oil from Canadians or is it only an american thing?


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## spacedout (Dec 7, 2010)

I have done oil testing in the past, but for the cost why not just change your oil? Sure your oil could go longer but wouldn't fresh oil be better than a somewhat broken down additive pack with 5000+ miles on it? 

I think changing the oil based on time(the 3 month part of the 3K typical oil change) is even more important than the actual mileage. Seems when more people started using full synthetic they forgot that part. The typical driver don't put on enough miles to go 7500+ to an oil change, that would probably be more than 6 months. An example is in the winter I put on less than 1000 miles a month, I certainly would not go 6 months or more on that oil that had tons of short trips, idling and longer winter warmup times. 

Already had my car in the dealer last January so had them change the oil, had only been around 2600 miles in 3 months. Could I have went longer? Sure but having dealt with sludge/condensation oil issues in the past, an oil change based on time is cheap insurance your car will last along time. 

BTW Synthetic oil is just as prone to condensation/sludge as anything else in short trip environments, which can block oil flow to key components. Have heard of a few turbo oil feed tubes getting coked up causing turbo failures in the cruze, why risk it when oil is cheap?


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## Blue Angel (Feb 18, 2011)

money_man said:


> Here's a question. Will Blackstone labs do testing on oil from Canadians or is it only an american thing?


I would just get a lab in Canada to do it. I used Wearcheck in Missassauga last time, this time I'm using Toromont CAT since they're much cheaper.


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## Blue Angel (Feb 18, 2011)

spacedout said:


> I think changing the oil based on time(the 3 month part of the 3K typical oil change) is even more important than the actual mileage. Seems when more people started using full synthetic they forgot that part.


I don't agree with that. Oil doesn't go bad just sitting in the pan unless it's full of fuel and moisture. The type of driving done before shutting the engine down will determine that. Surely making a half dozen short trips to grab milk in the middle of winter and then letting the car sit unused for six months probably won't do the oil any good, but unless that scenario applies I don't think it's worth worrying about. The OLM may even compensate for that, not sure.

Basically I think driving habits affect oil far more than time. My dad's Mazda calls for a synthetic oil change every 3k or 3 months, which in this day and age is absolutely laughable, unless you make your living running the service dept of a Mazda dealer.

I park my Corvette every winter and make sure I get he oil hot before shutting it down in storage, then I fire it up in the spring and don't worry about it. I change the oil in the fall about a month or so before it goes away since I'd rather have it sit with clean oil than dirty oil. I'm driving it now with the same oil I put in last October.


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## spacedout (Dec 7, 2010)

I guess your not understanding what I was saying, most peoples typical drive(based on 12K miles average a year) should not be going over 6 months to an oil change, especially in the winter. Thats only 32 miles a day average, however when below zero it takes my cruze most of that distance just to reach full operating temperatures. 

So acids don't build up in the oil? I would certainly change the oil in any car I store before it goes into storage for that reason alone. My typical winter driving is 95% city with 4-8 minutes of remote start daily. However my car is driven over half the time not fully warmed up, so yes condensation could be is an issue. 

Do you need to change oil every 3 months? No but I also don't think basing on mileage alone is a good idea. If you drive less than 1000 miles a month it certainly would be more beneficial to change oil every 3-4 months no matter the mileage just to avoid any sludge/condensation issues.


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## XtremeRevolution (Jan 19, 2012)

spacedout said:


> I have done oil testing in the past, but for the cost why not just change your oil? Sure your oil could go longer but wouldn't fresh oil be better than a somewhat broken down additive pack with 5000+ miles on it?
> 
> I think changing the oil based on time(the 3 month part of the 3K typical oil change) is even more important than the actual mileage. Seems when more people started using full synthetic they forgot that part. The typical driver don't put on enough miles to go 7500+ to an oil change, that would probably be more than 6 months. An example is in the winter I put on less than 1000 miles a month, I certainly would not go 6 months or more on that oil that had tons of short trips, idling and longer winter warmup times.
> 
> ...


There is nothing out there to suggest that 5000 mile oil protects better than brand new oil if the additives hold up. If you make the argument of not waiting too long, you are then required to specify just how long is too long. You threw out 5000. Why 5000? Why not 4000 or 3000 or 2000? What is the basis for 5000? Why not 5500? 

They didn't forget about the time aspect. Synthetic oils don't oxidize like conventional oils do when they sit. Furthermore, the antioxidant package in synthetic oils is more robust. For example, AMSOIL specifies OEM drain intervals or 3 months with the OE oil. 10k miles or 6 months with the XL oil. 15k-25k miles or 1 year with the SS oil. Those have varying base stocks and additive packages. We didn't forget; we simply used a better oil. 

There is an enormous difference between condensation and sludge. Sludge is due to oxidation. Condensation is due to a failure to bring the engine up to operating temp. The cooked oil in the feed and return lines used the dexos1 synthetic blend on way over 10k intervals. It doesn't even apply here. We shouldn't be making decisions and recommendations based on fear of the unknown, but based on knowledge of the known, and in that regard we know enough to recommend far more than 5k on a synthetic oil. 



spacedout said:


> I guess your not understanding what I was saying, most peoples typical drive(based on 12K miles average a year) should not be going over 6 months to an oil change, especially in the winter. Thats only 32 miles a day average, however when below zero it takes my cruze most of that distance just to reach full operating temperatures.
> 
> So acids don't build up in the oil? I would certainly change the oil in any car I store before it goes into storage for that reason alone. My typical winter driving is 95% city with 4-8 minutes of remote start daily. However my car is driven over half the time not fully warmed up, so yes condensation could be is an issue.
> 
> Do you need to change oil every 3 months? No but I also don't think basing on mileage alone is a good idea. If you drive less than 1000 miles a month it certainly would be more beneficial to change oil every 3-4 months no matter the mileage just to avoid any sludge/condensation issues.


Again, acid doesn't build up in oil when it sits. It simply oxidizes when exposed to oxygen. Oxygen, being a negative polarity, reacts with hydrogen in the hydrocarbon chains, being a positive polarity. The hydrocracking process in group 3 oils greatly reduces a synthetic oil's tendency to oxidize. Acidity is built up as a byproduct of the combustion chamber, which is neutralized by your detergent package, tested as TBN.

Most condensation issues can be resolved with a longer drive at operating temp. Changing the oil at the bottom of the pan won't solve the condensation on the components in the valvetrain. 

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## money_man (Feb 25, 2014)

Blue Angel said:


> I would just get a lab in Canada to do it. I used Wearcheck in Missassauga last time, this time I'm using Toromont CAT since they're much cheaper.


I didn't know there was labs in Canada that did this


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## Blue Angel (Feb 18, 2011)

money_man said:


> I didn't know there was labs in Canada that did this


Find your local CAT heavy equipment dealer and give them a call. My local dealer here in Ottawa sells a UOA kit including pre-paid shipping with Canada Post for around $22. Wearcheck was closer to $50 when it was all said and done since shipping is on you.


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## money_man (Feb 25, 2014)

Good to know!


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## TeckyWalla (Aug 30, 2019)

I know this is a bit of a legacy thread, but am curious as to the life of Dexos2, I thought a synthetic carried greater mileage between changes.
This is a 2 yr old Cruze LT (gas ver) and I had the last free oil change under the warrenty, since then I have only driven 2800Kms and get the change oil msge, and the display shows 3% oil life left.
3000kms seems heck of a low value to change oil at, in light of using synthetic.
What are the thoughts?
T.


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## jblackburn (Apr 14, 2012)

TeckyWalla said:


> I know this is a bit of a legacy thread, but am curious as to the life of Dexos2, I thought a synthetic carried greater mileage between changes.
> This is a 2 yr old Cruze LT (gas ver) and I had the last free oil change under the warrenty, since then I have only driven 2800Kms and get the change oil msge, and the display shows 3% oil life left.
> 3000kms seems heck of a low value to change oil at, in light of using synthetic.
> What are the thoughts?
> T.


Dexos 2 is a diesel oil.

Dexos-1 Gen 2 (synthetic that meets LSPI specs for GM's tests) is a more or less a semi-synthetic/full synthetic oil that has certain concentrations of additives to help prevent piston-destroying LSPI events. It isn't necessarily any better longevity-wise.


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## TeckyWalla (Aug 30, 2019)

Yeah, my bad, I meant Dexos 1.
So it wouldn't be considered oddly low mileage at 3Km?


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## jblackburn (Apr 14, 2012)

TeckyWalla said:


> Yeah, my bad, I meant Dexos 1.
> So it wouldn't be considered oddly low mileage at 3Km?


Oil life is calculated by time or mileage, whichever comes first. 1 year is typically what's recommended for continued protection as the oil/additives break down.

Both of our cars are coming up on ~1 year and I will be changing it, even though they've done <5000 miles this year.


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