Chevrolet Cruze Forums banner

1 - 20 of 48 Posts

·
Administrator
Joined
·
15,685 Posts
Discussion Starter #1 (Edited)
To shed some light on oil drain intervals and the marketing scam behind Jiffy Lube's "3000 miles for a well-oiled machine." (owned by Pennzoil, courtesy of Shell oil), I performed a quick search of some vehicles/engines used in the UK and their respective drain intervals through google.co.uk.

Fiat Multijet 1.3L: 20,000KM (12,500 miles) or 1 year
Opel 1.3L: 30,000KM (18,000 miles) or 1 year
Fiat 500 1.4L: 30,000KM (18,000 miles) or 1 year
Alfa Romeo 147 1.6 TS: 20,000KM (12,500 miles) or 1 year
Vauxhall Astra 1.4L: 18,000 miles or 1 year
Vauxhall Corsa: 20,000 miles or 1 year
Vauxhall Vectra C: 20,000 miles or 1 year
Peugeot 206 CC: 20,000 miles or 2 years
BMW 325i: 15,000 miles or 1 year
Renault Clio: 18,000 miles or 1 year
Renault Modus: 12,000 miles or 1 year
Ford C-Max 1.6: 12,000 miles or 1 year
Audi Q5: 20,000 miles or 1 year
Mercedes-Benz Vito Taxi: 18,000 - 24,000 miles
Toyota Corolla/Prius: 10,000 miles or 1 year
Nissan Juke 1.6: 18,000 miles or 1 year
Volkswagen Polo: 15,000km (9,300 miles) or 1 year
Ford Fiesta: 12,000 miles or 1 year
Citroen DS3 Cabrio: 20,000 miles or 1 year (check out the list at http://info.citroen.co.uk/.../caring.../service-intervals)
Dacia Logan: 30,000km (18,000 miles) or 1 year
Audi A1 (and all new audis): 9,000 miles fixed or 18,000 miles variable (oil life monitor) or 1 year. Most of the results I've seen have people changing at 14,000-18,000 miles or 2 years.

Audi A1 (and all new audies): 9,000 miles fixed or 18,000 miles variable (oil life monitor) or 1 year. Most of the results I've seen have people changing at 14,000-18,000 miles or 2 years. I've been trying to tell people for a long time now that there is a massive oil quality problem in the US, and that a longer drain interval with a quality synthetic oil such as the ones commonly found in the UK and most of Europe are not only perfectly safe, but advised for engine longevity and are capable of saving you quite a bit of money, maintenance, and downtime. Europe uses brands such as ELF, MOTUL, and TOTAL QUARTZ to name a few. You will notice that those are curiously not readily available in the US.

We do, however, have AMSOIL Signature Series as a true synthetic.
AMSOIL SAE 5W-30 Signature Series 100% Synthetic Motor Oil

We also have AMSOIL XL for those who don't want to push the car past 10,000 miles...
AMSOIL SAE 5W-30 XL Extended Life Synthetic Motor Oil

..and AMSOIL OE for those who want to stick to their manufacturer recommended oil drain intervals.
AMSOIL SAE 5W-30 OE Synthetic Motor Oil
 

·
Registered
Joined
·
191 Posts
I just changed the oil in my Cruze last week, the first time since switching to a synthetic (Mobil 1, 5W-30). The first few oil changes I used Dexos 1- approved semi-synthetics, and changed the oil at ~50% oil life monitoring (OLM). At 50% OLM, the semi-synthetic was black and had some burned-oil smell. The synthetic I changed out last week was at about 30% OLM, and looked nearly as clean as new oil. Went with Castrol Syntec 5W-30 this time since it was on sale at Autozone. I'll probably go to 20% OLM this time since the oil looked so clean at 30%.
 

·
Administrator
Joined
·
15,685 Posts
Discussion Starter #3 (Edited)
I just changed the oil in my Cruze last week, the first time since switching to a synthetic (Mobil 1, 5W-30). The first few oil changes I used Dexos 1- approved semi-synthetics, and changed the oil at ~50% oil life monitoring (OLM). At 50% OLM, the semi-synthetic was black and had some burned-oil smell. The synthetic I changed out last week was at about 30% OLM, and looked nearly as clean as new oil. Went with Castrol Syntec 5W-30 this time since it was on sale at Autozone. I'll probably go to 20% OLM this time since the oil looked so clean at 30%.
I've gone into details regarding this stuff in another thread, but I'll cut it short for this response.

Mobil 1, Castrol Edge (with Syntec) are not true synthetics. In the mid to late 2000s, the big oil conglomerates sold us out to a petroleum based oil and slapped a "synthetic" label on it. For some companies, it happened as early as 2006, but some of them waited till as late as 2011. In either case, they sold out and the numbers prove it. Around 2011, you will notice that Royal Purple came out with a "new" HPS oil. The truth is that their original Royal Purple formulation was re-badge as Royal Purple HPS, and their standard Royal Purple bottle sold out to a group 3 petroleum oil that thins down to a 20-weight oil within 3,000-5,000 miles and doesn't have their synerlec additive package.

These new "synthetics" are only called as such due to a legal loophole that allows them to bend the definition of the word. The base stocks are actually called group 3 hydrocracked base stocks, which are nothing more than heavily purified petroleum oils. Conventional oils contain lots of contaminants that are impossible to remove through the refining process, so what they do is put it under high pressure and heat so they can vaporize the oil and separate the lubricating hydrocarbons from the contaminants by molecular weight. They then blast it with ionized hydrogen and liquify it again into a pure oil.

It is a very pure oil, but it is still a petroleum oil from the ground, and its molecular structure is the same. This is what you now buy as a "synthetic" with a Mobil 1, Valvoline, Pennzoil, Quaker State, Royal Purple, Castrol, etc. badge. Some of these oils use a small percentage of true PAO synthetic base stocks as a blend, but none of them are true 100% synthetic base stocks. AMSOIL XL and AMSOIL OE are among the group 3/group 4 hybrids. AMSOIL Signature Series is a 100% group 4/group 5 PAO/Ester formulation. Redline is a 100% Ester formulation. The oils you are using are just purified petroleum oils sold as "synthetics." They are not true synthetics. It is the industry's biggest sellout, and the worst part of it all is that they didn't tell anyone. Everyone is still buying those overpriced bottles based on the reputation those companies had back when they were real synthetics.

The oil drain intervals I mentioned in the original post are based on true synthetics, as they do not use petroleum oils in any significant quantities in the UK as it is far more expensive. This is also the reason you see so many Diesels out there. It is simply cheaper than petrol (gas). If you want to see the numbers that prove that all of these oils sold out, I can show them to you as well.
 

·
Premium Member
Joined
·
906 Posts
Love it!! Keep posting info like this or links to articles that you come across doing your T-1 certification testing with Amsoil or even fwd said articles to me I would love to read all of them!!
 

·
Premium Member
Joined
·
6,918 Posts
One of my friends decided a few years ago with his then new chevy trail blazer to use amsoil and change once a year(less than 15,000 to an oil change). Motor was fine for 3 years, but ended up spinning a bearing at 70,000miles. He even swapped the filter at 6 months and did oil analysis.

As cheap as oil is there is absoutly no good reason to risk thousands of dollars in engine damage with such a long drain interval. Heck even oil analysis cost is not worth it, cost 3/4 the price of just changing your oil.

I change my oil every 6,000miles or 3 times a year with mobil 1. Total cost for oil changes is under $150 for the year and I don't even have to get my hands dirty as I have the dealer do the work. That also goes along way in building a relationship with the service department and getting a better level of service.
 

·
Registered
Joined
·
310 Posts
First of all, I'm a chemist. I've only recently starting researching the oils and their composition, but I do find all of it quite interesting. Hydrocracked means there are chemical reactions taking place to change (shorten) the carbon chain lengths of the molecules. According to the definition of synthetic, the group 3 oils are synthetic in the sense that the molecules in the oil are not the same as the ones in the original crude oil.

Group 4 and 5 start with purer substances (such as PAO (polyalphaolefins), although these substances still come from crude oil). Because of this, the synthesis reactions could in principal (and probably do in real life) give a product with a more controlled composition.

Despite these facts, there is nothing in either synthesis method that guarantees the group 4/5 oils are better or longer lasting lubricants. I'm also not saying the group 3 oils are better either, only that the most basic facts about their synthesis aren't a predictor of quality. I can certainly see why the group 4/5 oils are more expensive. Group 3 would almost certainly be easier/cheaper to make. If the tests and UOA's say that groups 4/5 are better, than so be it, but group 3 oil most definitely are synthetic according to any chemist's definition. The synthesis process is quite different however.

This is my understanding of how synthetics are made based on what I've been able to find and read and my experience as a chemist. I'm not for or against any type of oil. My 02 Oldsmobile ran for 212000 trouble free (from an engine standpoint) miles on valvoline max-life synthetic blend. My 08 Odyssey is at 105k with no issues using mobil 1. My Cruze only has 1000 miles on it and I'm not sure what oil I'm going to run in it yet. That's why I've been reading these types of threads.... :)
 

·
Administrator
Joined
·
15,685 Posts
Discussion Starter #8 (Edited)
One of my friends decided a few years ago with his then new chevy trail blazer to use amsoil and change once a year(less than 15,000 to an oil change). Motor was fine for 3 years, but ended up spinning a bearing at 70,000miles. He even swapped the filter at 6 months and did oil analysis.

As cheap as oil is there is absoutly no good reason to risk thousands of dollars in engine damage with such a long drain interval. Heck even oil analysis cost is not worth it, cost 3/4 the price of just changing your oil.

I change my oil every 6,000miles or 3 times a year with mobil 1. Total cost for oil changes is under $150 for the year and I don't even have to get my hands dirty as I have the dealer do the work. That also goes along way in building a relationship with the service department and getting a better level of service.
I strongly resent the implication that AMSOIL or his extended drain interval caused him to spin a bearing. Why? Because AMSOIL has a warranty that protects him from an engine failure. The fact that you did not mention AMSOIL repairing the vehicle for him suggests that there were other factors involved that he either did not tell you or that you aren't telling us. The warranty statement is pretty clear. If at the time of failure, the oil is tested and is determined to be out of spec, AMSOIL will cover the repair. If the oil is found to be out of spec and the correct interval was followed, AMSOIL will repair the vehicle.

There are millions of people across all of Europe that go a minimum of 10,000 miles on an oil change (as I very clearly outlined in the first post of this thread), and plenty of vehicles in the US that run well past 15,000 miles on an oil change using AMSOIL synthetic lubricants. There are in fact vehicles that run beyond 25,000 miles on a change of oil, although those are typically courier vehicles. Unless you have proof that the oil caused the failure, please refrain from suggesting that it did, especially when used oil analysis routinely proves that oil is suitable well past the 10,000 mile mark. I can't begin to tell you how many spun bearings I've personally seen with dino oil. A catastrophic oil-related failure is an extremely rare occurrence.
 

·
Administrator
Joined
·
15,685 Posts
Discussion Starter #9 (Edited)
First of all, I'm a chemist. I've only recently starting researching the oils and their composition, but I do find all of it quite interesting. Hydrocracked means there are chemical reactions taking place to change (shorten) the carbon chain lengths of the molecules. According to the definition of synthetic, the group 3 oils are synthetic in the sense that the molecules in the oil are not the same as the ones in the original crude oil.

Group 4 and 5 start with purer substances (such as PAO (polyalphaolefins), although these substances still come from crude oil). Because of this, the synthesis reactions could in principal (and probably do in real life) give a product with a more controlled composition.

Despite these facts, there is nothing in either synthesis method that guarantees the group 4/5 oils are better or longer lasting lubricants. I'm also not saying the group 3 oils are better either, only that the most basic facts about their synthesis aren't a predictor of quality. If the tests and UOA's say that groups 4/5 are better, than so be it, but group 3 oil most definitely are synthetic according to any chemist's definition. The synthesis process is quite different however.

This is my understanding of how synthetics are made based on what I've been able to find and read and my experience as a chemist. I'm not for or against any type of oil. My 02 Oldsmobile ran for 212000 trouble free (from an engine standpoint) miles on valvoline max-life synthetic blend. My 08 Odyssey is at 105k with no issues using mobil 1. My Cruze only has 1000 miles on it and I'm not sure what oil I'm going to run in it yet. That's why I've been reading these types of threads.... :)
I have discussed the basics of hydrocracking. The purpose of hydrocracking is to separate contaminants from hydrocarbons. At the end of the day, you still have a petroleum base stock. The oil is heated and put under pressure so it can be vaporized, where the hydrocarbons can be separated from the contaminants by molecular weight, thus the term cracking. The hydro part refers to the "blasting" of the remaining hydrocarbons by ionized hydrogen to reduce the effects of oxidization. The end result is an oil that will still be limited by the chemical properties of petroleum oils because it is not truly synthetic. It is more accurately defined as purified. PAO/Ester synthetics are most accurately compared to plastics. Nothing you purify from the ground will take the form of plastic. Like PAO/Ester base stocks, plastics are truly synthetic.

There is in fact a testing method that guarantees the Group 4/5 oils will last longer, which is called NOACK volatility. The oil is heated to 250C for one hour and then measured for weight loss. A good synthetic like AMSOIL Signature Series will come back at 6.9% weight lost. A "hydrocracked" synthetic will come back at 10-15%. NOACK volatility is quite important.

On top of that, you have a need for far more pour point depressants and viscosity index additives in group 3 base stocks than you do in Group 4/5 base stocks, which further affects volatility.

These topics have been discussed in great detail in this thread:
http://www.cruzetalk.com/forum/10-powertrain/41385-tiered-oils-list-understanding-synthetics.html
 

·
Premium Member
Joined
·
6,918 Posts
I strongly resent the implication that AMSOIL or his extended drain interval caused him to spin a bearing. Why? Because AMSOIL has a warranty that protects him from an engine failure.
I did not get into the hastle he had to go though even with their warrenty to get things covered, as it would have look like I was trying to make amsoil look bad. Thats not the case. Sure thing were eventually covered but not until he got a third party oil anaysis involved and was considering getting an lawyer if that did not do the trick.

Any oil on extended drain can be a problem, does not matter the brand. Some people can go 10,000-15,000 miles but to say it safe for everyones driving habbits is not the case. I too have done 10,000 mile oil changes in the past which is around one change a year with no ill effect, I drive 70% or more highway though.

To each his own, but to me why risk $8,000-10,000 engine relacement and being out your car for a month just to save $50 and 30 minutes on an oil change? Sure some oil breaks down slower but there is no way amsoil or anything else at 10,000+ miles is as good as fresh full sythetic oil. Any suspended soilds not trapped by the filter, metals that are accumilating & acids that are building will start causing more wear.

This can easily be shown, test fresh amsoil or anything else your running, then test the same oil at 10,000miles. Which one has better numbers? If you think driving around on oil that test ok is as good as changing with fresh oil your fooling yourself.
 

·
Administrator
Joined
·
15,685 Posts
Discussion Starter #11 (Edited)
I did not get into the hastle he had to go though even with their warrenty to get things covered, as it would have look like I was trying to make amsoil look bad. Thats not the case. Sure thing were eventually covered but not until he got a third party oil anaysis involved and was considering getting an lawyer if that did not do the trick.

Any oil on extended drain can be a problem, does not matter the brand. Some people can go 10,000-15,000 miles but to say it safe for everyones driving habbits is not the case. I too have done 10,000 mile oil changes in the past which is around one change a year with no ill effect, I drive 70% or more highway though.

To each his own, but to me why risk $8,000-10,000 engine relacement and being out your car for a month just to save $50 and 30 minutes on an oil change? Sure some oil breaks down slower but there is no way amsoil or anything else at 10,000+ miles is as good as fresh full sythetic oil. Any suspended soilds not trapped by the filter, metals that are accumilating & acids that are building will start causing more wear.

This can easily be shown, test fresh amsoil or anything else your running, then test the same oil at 10,000miles. Which one has better numbers? If you think driving around on oil that test ok is as good as changing with fresh oil your fooling yourself.
Getting a third party analysis done isn't what I would consider a big hassle, but without seeing the difference between the two testing results, I can't comment further so I won't.

Brand certainly matters. Not all oils are created equal as I have pointed out here in the past. Also, not all cars are created equal, which is why we test oil to begin with. The notion that those intervals are not safe for everyone is exactly why AMSOIL clarifies the difference between normal service (25k miles) and severe service (15k miles).

I disagree entirely. I do believe that AMSOIL at 10,000 miles with plenty of moly, boron, and a significant TBN remaining will be better than some other "synthetic" oils out there that lack the anti-wear and extreme pressure additives that the AMSOIL will still have by that point. Suspended solids are not a concern as it is the filter's job to trap any particles large enough to cause damage. That is the entire purpose of the filter to begin with. We are talking about particles that are mere microns in size. As for the acids, that is the entire purpose of testing for TBN. TBN (total base number) refers to the oil's remaining ability to neutralize acids. Some people opt to test TAN (total acidity number) as well. Acids will only begin to cause wear once the oil fails to neutralize them, which again is reflected by testing TBN. It is interesting that you bring this up, as TAN is exactly why I stay clear of Mobil 1. They use Mg-based detergents, which have been proven to be less effective at neutralizing acidity as Ca-based detergents.

It is obvious that fresh AMSOIL will test better than used AMSOIL. There is no doubt about that, but the problem comes when you try to put a specific mileage on exactly when that oil should be changed. The purpose of this thread was to raise awareness of what the rest of the world is doing. Compared to our marketing-driven 3,000 mile drain interval with dino oil, we are wasting billions of dollars. Why is it that we can't go past 3k miles and they can go 10k-20k miles?

If I gave you a sample of AMSOIL Signature Series at 10,000 miles, I guarantee you it would look better (assming there were no unusual external factors involved) than Mobil 1 at 6,000 miles. Sure, fresh oil will always test better, but where do you draw the line and why? Why 6,000 miles and not 7,000 miles or 8,000 miles or 9,000 miles. What data-driven metric do you use to follow that interval? Proximity to oil life monitor recommendations and previous experience with inferior designed vehicles using inferior oils? If all of Europe can go up to 20,000 miles normal service for an oil drain interval, why have you chosen 6,000 miles? One can respond the same way you have and say, "wouldn't the oil test better at 5,000 miles than it does at 6,000?"

We test for wear metals in oil testing analysis to see how well the oil protects that engine. Earlier in the week, I posted an oil testing analysis of an AMSOIL 0W-30 change of oil taken by a friend at 11,200 miles on his 1.4L Turbo Cruze ECO. Engine had ~100k miles on it. The oil had significant fuel contamination from his excessive idling (1-5 hours), which occurred at low (140 degrees) engine temperatures, and his liberal use of the throttle while being tuned by vtuner. Despite the oil thinning to a 20-weight and the anti-wear and extreme pressure additives showing signs of depletion, his wear metals were almost nonexistent, indicating that the oil was doing a perfectly good job at that mileage of protecting his engine. According to Blackstone, TBN becomes too low once it drops below 2.0. His TBN was at 5.6, which indicates that 15,000 miles would have been easily achievable had his conditions not subjected his oil to fuel dilution.

Again, where do you draw the line and why? I draw the line at 15,000 miles maximum with the 1.4T Cruze no matter what conditions are present. Given that our oil testing analysis with inferior oils such as Mobil 1 have suggested we can go well beyond 10,000 miles, I would say the sky-high TBN of AMSOIL Signature Series will have no problem going another 5k miles.

Since my vehicle is Trifecta tuned, I will get the analysis done at 10k miles.
 

·
Premium Member
Joined
·
6,918 Posts
where do you draw the line and why? Why 6,000 miles and not 7,000 miles or 8,000 miles or 9,000 miles. What data-driven metric do you use to follow that interval?
This is a great question but the answer should differ slighlty for everyone. I did my own oil testing with the dealer fill dexos blend and it was showing around 7500 miles I could safely go. However I decided to use oil analysys I have seen on cruzetalk(most worse than mine) and averaged 6,000 miles I could go on the dexos blend safely.

Most people forget the 3 month part of the 3,000 mile oil change and this is just as important. In the winter I idle a ton more and drive allot more short trips on a cold engine. december-april I will not typically drive 6,000 miles, but want to change once the weather warms. This how I chose the every 4 months(or 3 times a year) part of my oil change regiment.

Since we all know any full synthetic is better than the dealer dexos blend, I switched to mobil 1. Even with mobil 1 I follow the 6,000mile/4 month change interval. This ensures my engine is always running with fresh clean oil and never has broken down or accumilated to much condensation.


EDIT: I should add my DIC oil life monitor has never seen below 40%, on my 2012 it always indicates around a 10,000 mile oil change.
 

·
Administrator
Joined
·
25,372 Posts
The engine oils generally available in the US are not of the same quality as the engine oils in Europe. Our gasoline is also lower quality. Unfortunately retraining Americans to pay more for gasoline or engine oil in order to have better fuel economy and vehicle life simply isn't going to happen. Thus the wonderful 3,000 mile oil change stickers even on cars that are designed for longer oil changes. Even with the best engine oil on the planet the Cruze's Oil Life Monitor is still going to trigger a oil change request somewhere around 10,000 miles so this is effective upper limit for oil change mileage, even when using AMSOil. My concern is that ignoring the OLM will cause GM to try to void the power train warranty even when the problem wasn't engine oil related.

The good part of this is that the 2011s and 2012s should be able to safely go to their full OLM change oil trigger, unlike with the AC Delco dexos 1 blend.

Poking around the AMSOil web-site I noticed AMSOil sells different engine oils in Europe from those they sell in the United States. I'm assuming this is due to differences in the gasoline and subsequent burn characteristics.
 

·
Registered
Joined
·
310 Posts
I have discussed the basics of hydrocracking. The purpose of hydrocracking is to separate contaminants from hydrocarbons. At the end of the day, you still have a petroleum base stock. The oil is heated and put under pressure so it can be vaporized, where the hydrocarbons can be separated from the contaminants by molecular weight, thus the term cracking. The hydro part refers to the "blasting" of the remaining hydrocarbons by ionized hydrogen to reduce the effects of oxidization. The end result is an oil that will still be limited by the chemical properties of petroleum oils because it is not truly synthetic. It is more accurately defined as purified. PAO/Ester synthetics are most accurately compared to plastics. Nothing you purify from the ground will take the form of plastic. Like PAO/Ester base stocks, plastics are truly synthetic.
I'm not disagreeing with anything else you've said (especially all the bit about volatility which is very good info), but defining hydrocracking as purifying is not correct. Hydrocracking is breaking apart the molecules from the feedstock into smaller ones. This is a chemical reaction, not a purification which is a physical process. This is why group 3 oils are labelled synthetic.

Also, you say nothing that you purify from the ground will take the form of a plastic, but that's exactly what plastics are (except again, not purified). They are made (again chemically) from crude oil via polymerization reactions. These plastics (in this case PAOs) are then chemically reacted into the group 4 synthetics. As I said in my earlier post, there is far more chemistry (synthesis) involved in making the group 4/5 synthetics vs the group 3. Perhaps a better or clearer way to say it is that group 3 oils are synthesized DIRECTLY from crude oil (and may contain some unchanged molecules from the crude, I'm assuming there are limits here as to what can be labeled synthetic), whereas groups 4/5 are synthesized from crude oil derivatives (at least 2 steps). In groups 4/5, I'm assuming none of the molecules are in the same state as they were in the crude (for this you used the term "truly synthetic").

If we ever run out of crude oil from the ground, there will be no plastics or synthetic oils as we know them today as our raw material is gone in all cases.

I'm really not trying to be argumentative as I agree with everything you've said. It's just the chemistry teacher in me being particular about the terminology used to explain it. :)
 

·
Premium Member
Joined
·
6,918 Posts
Go study the Oil Analysis reports on bobistheoilguy.com . You'll see that most of the name brand synthetic oils sold in the US today have no problem making it to 10k and beyond.
Thats the problem though everyones drive is different. One should base thier change interval on their own oil testing. Thats not even taking into consideration how the same oil behaves differently in each engine, because of that only oil analysis done on the 1.4T should be used as reference.
 

·
Administrator
Joined
·
25,372 Posts
Thats the problem though everyones drive is different. One should base thier change interval on their own oil testing. Thats not even taking into consideration how the same oil behaves differently in each engine, because of that only oil analysis done on the 1.4T should be used as reference.
Part of the OLM algorithm in the Cruze monitors engine speed, road speed, acceleration and decelerations. Basically it tracks how you drive.
 

·
Premium Member
Joined
·
6,918 Posts
Part of the OLM algorithm in the Cruze monitors engine speed, road speed, acceleration and decelerations. Basically it tracks how you drive.
On that same note though it does not know what you actually put in your car and dos not actually test the oil. One could change oil based on the DIC reading but not without actually sending oil in for analysis, otherwise one would just be guessing.

Since we know none of the algorithum parameters I almost doubt its that complex. My drive is so different from my friend with a cruze, yet both our 2012 cars say around 10,000 miles on the oil life monitor. From this very small sample and what I have read on here it almost appear to be based soley on mileage. I can actually say I never heard of a 2012 cruze that did not indicate a 10,000 mile oil change.
 

·
Administrator
Joined
·
25,372 Posts
GM adjusted the algorithm for the 2013s to reduce the estimated oil life by about a third, but the underlying algorithm most likely hasn't changed in the past decade. My 2002 Montana had an OLM as well. Other than the oil itself, there simply aren't very many variables to monitor - engine temperatures, engine speed, vehicle speed, how hard you accelerate with regards to shift points, etc.

As for the oil quality I believe we can safely assume the OLM assumes the base level of dexos 1 certification.
 

·
Premium Member
Joined
·
4,645 Posts
From this very small sample and what I have read on here it almost appear to be based soley on mileage. I can actually say I never heard of a 2012 cruze that did not indicate a 10,000 mile oil change.
If that was true, everyone's car would report an oil change needed at exactly the same mileage which is not the case.

People who do long steady drives at highway speed will be easiest on oil per mile driven, and people who do many short trips without warming the oil properly will be hardest on their oil per mile driven. Mix that up with a variable based on time and you've probably got 90% of the info the DIC requires to estimate oil life.

My last oil change was done way before the OLM said it was necessary, but working it out the OLM would have gone to 0% somewhere above 18,000km (11,000+ miles) if my driving stayed consistent.
 
1 - 20 of 48 Posts
Top