A More Expensive Oil Change

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You may have heard/read about the new “Dexos” oil – the oil GM requires you use in all its cars built from model year 2011 forward (else risk voiding your warranty coverage in the event there’s an engine problem that can be attributed to using non-Dexos oil).Dexos 1

There has been some misleading coverage – and some omission of coverage – I thought it’d be worth getting into.

First, “Dexos” does not = “GM.” In other words, you do not have to buy GM (i.e., AC Delco) oil.

GM got some flack for – supposedly – creating a captive market for itself, by demanding that people who own GM cars use only GM oil. This is not true. “Dexos” is a standard – not a brand. Any oil – made/sold under any brand label is ok to use in your GM vehicle  . . . so long as it meets the Dexos standard specified by GM.Dexos 2

So, you can still use Castrol, Mobil1, Havoline (to name just a few; see here for a complete roster) and not risk voiding your new car warranty, provided the oil meets the specified GM Dexos standard. Look for the label, as in these photos.

The confusion arose because GM – rather than the American Petroleum Institute (API) issued the standard. Americans are used to seeing the API service rating sticker (see here for more) not a GM trade name. In Europe, it is common for car companies to issue their own “mandatory minimums” – and GM is just doing what’s routinely done in Europe.

So, the good news is GM hasn’t created a monopoly for itself; you can still cross-shop. There will still be price competition between brands.

The bad news is you do have to buy the higher-cost Dexos-spec. oil if you own a 2011 or newer GM car. And it’s becoming more expensive to change your car’s oil – GM car or not.Dexos 3

Dexos1 (the spec for gas-engined cars) costs about $5-$6 a quart, depending on where you buy (and depending on the label) vs. about $4 a quart for a high-quality non-synthetic such as Pennzoil. Most car engines need about 5 quarts at oil change, so you’ll be paying about $5 more at each oil change.

Part of the reason for the price difference is that Dexos is a semi-synthetic blend – and semi-synthetics cost more than conventional, non-synthetic oils. But the real reason for the increased cost is the additive package – which is what makes Dexos oil “Dexos” oil. The additive package was formulated for the latest generation new car engines, which have specific design characteristics and features that are rapidly becoming commonplace – such as variable cam timing, and turbochargers, which put extra stress on an engine and which also generate extra heat. The protective additives (and semi-synthetic blends) are great . . . if your car needs them. All 2011 and newer GM cars do.

But your car may not.wear and tear 1

And that’s the problem – or will be. Dexos – the standard – is probably going to become the new baseline standard for all motor oil. Because it’s not just GM that is equipping its new cars with engines that need Dexos-level/Dexos-equivalent oil in order to keep pace with federal fuel efficiency and emissions mandates – and to prevent or at least reduce some of the problems potentially attributable to these mandates. For example, excess wear and tear caused by the start-stop cycles of the “Auto-Stop” systems being fitted to many new cars as a way to improve their fuel economy. Or the need to reduce oil foaming (aeration) to nil – in cars equipped with engines that have hydraulically actuated (oil-activated) cam timing systems.

The new industry-wide API/ILSAC (International Lubricants Standardization and Approval Committee) standard is now GF-5, which superseded GF-4. GF-5 is not quite as high a standard as Dexos – but it’s close. And the relevant fact is that most new cars – regardless of make/model – already require GF-5 (or Dexos).api sticker pic Within a few years, all new cars will require these oils.

Existing (less expensive) oils that do not not meet the latest GF-5 (and Dexos) standard will be phased out. It will still be available, but as supplies decrease – as the companies that make oil shift production over to the new baseline GF-5 (or Dexos) – the older-spec (and less expensive) oil is going to become harder and harder to find. Eventually, it will be a specialty oil – and probably cost more than Dexos/GF-5 oil.

So, in the end, we’ll all be paying more for oil changes because the cost of oil is going up.

Put another way, it means we’ll all be paying more for the cost of government mandates. The mandates that “nudged” the car companies to design engines that require more expensive-to-make oil – which will in time become the only oil that’s mass-market available.Dexos ILSA

Something else, too. The latest formulations are supposedly better at helping prevent internal engine problems caused by the use of ethanol fuels, especially E85 (85 percent ethanol). That’s wonderful – except for the fact that it’s the ethanol that’s the problem. Get rid of the ethanol and the need for special oil to protect the engine from the consequences of burning ethanol rather than gas disappears.

One last thing: Dexos and GF-5 oils are touted as being ok to use in older car engines, but there is concern that the very low levels of certain additives in these oils (in particular, zinc and manganese) which have been removed or nearly removed in order to increase the service life of emissions related components (principally, catalytic converters) may increase wear and tear in older engines that need these additives. If your vehicle is newer than 1990, you are probably ok – as the worry is mostly about engines that have what are called flat-tappet camshafts, which have not been in widespread production since the ’80s. Still, no one really knows what the long-term effect of using oils formulated for 2011-up engines may do to engines made before then. We may enjoy increased oil-change intervals – one of the touted benefits. But we may also see increased wear and tear and shorter engine life.oil change pic

One thing’s for sure, though: The cost of changing your car’s oil is going up.

Throw it in the Woods?

* Kudos to Dom and Geo for this one.




  1. In fact, dexos1 can be *cheaper* than the older 4718M spec that it supercedes.

    That’s because dexos1 synthetic blend oils are actually high enough quality that they can be used in older (4178M) cars that required a full synthetic in the past.

  2. Does GM 6094M, or WSS-M2C934-A, or MS-6395 or HTO-06 or 506.1 diesel look familiar to anyone?
    These are all vehicle manufacturer oil specifications. In order they are: GM, Ford, Chrysler, Honda, Volkswagen. Anytime a manufacturer comes up with an engine that requires a higher quality oil, not only to protect the engine, but the emission system and environment – they will issue an updated manufacturer specific oil specification.
    When GM began the specification Dexos, they got away from the manufacturer specific numbering system and basically went to a logo that is becoming a recognizable household ‘brand’.
    Whether you drive a GM vehicle or not, you’re still likely a slave to a manufacturer specific oil specification and just haven’t equated the requirement in the owner’s manual to the number on the back of a quart of oil. GM just makes it easy by calling theirs Dexos with a recognizable logo.
    By the way, GM has paid back all government loans + interest, not only to the US government but the Canadian government as well. Also, people are back to work in the manufacturing business which helps our country to a great extent. Seems to me the investment of $ from our federal government was a great investment. But people are victims and unwilling to admit that the home team is doing something right.

    • Mark, I’m one of those who supported govt. helping of all the major auto makers simply because the supply line is so huge and employs so many. I didn’t go for BO replacing the CEO of GM since I think that’s govt. over-reach. Sure, it would be great to not have govt. involved in financing but it was govt. that caused most of the problem to begin with. It would be great to have a choice to drive any vehicle we wanted with insurance companies that choose to provide insurance for anything or anyone they want but we don’t…..and the insurance companies themselves are to blame as much or more than the politicians they buy to make everyone use their services. What a tangled web and all that.

      • The auto maker bailouts are what I consider a least wrong. Very wrong and shouldn’t have happened but they were a tiny tiny fraction of what was given to the banks. I consider all of QE nothing more than gifts to wall street and the big banks.

        Automaking has been circulating the crony capitalist drain since the 1930s. It’s difficult to tell the day to day corporate welfare from the outright bailouts. Much the same with the financial industry and wall street.

        But in total the amount going to auto making is trivial compared to what goes to wall street and the banks. Thus I can live with it being put aside until the gorilla in the room is dealt with, but that’s all. It too must be unwound.

        The trouble in unwinding it is that every government does it. Automakers expect it where ever they build a factory. Now why can’t an average guy get a few billion dollars? Well that’s what politics and regulation is for. To keep outsiders out.

        • Hi Brent,


          The octopus has tentacles that extend to every nook and cranny. I also feel for the individually innocent line workers, suppliers and so on just trying to earn their daily bread. But as you point out, the fact remains that because of crony capitalism, having (or not having) “pull” is often the key factor as to whether a given business succeeds or fails. The obstacles facing a start up – and here I refer to a nuts and bolts business that makes something physical such as a car or motorcycle – are almost insuperable. But a company like GM can obtain millions – even billions – in government “help”….

    • Subsitute “gang of armed thugs” for “government” in your next to last sentence and you may understand why so many of us here have a problem with it. It is not unknown for gangsters to do things in their neighborhoods that may actually benefit “the community.” But they are still gangsters nonetheless.

      Needless to say, I did not support the government bailout. There is also no way that I would consider a GM product if I were in the market for a new car. The American people were already forced at gunpoint to pay for GM once. I cannot imagine why anyone would voluntarily fork more over more of their hard-earned money to that turd of a company.

      • GM bailed out Chrysler long ago but I guess that’s not germane to this. Ford got bailed out in ’08 but that was kept hush hush. Like I say, I don’t like govt. of any sort. Since NAFTA and GATT we’re so screwed in this country for jobs it benefits the entire nation to not let Ford or GM either go bankrupt and stop literally millions of jobs. I don’t like it and like what created this problem even less.

        Ross was correct about that big sucking noise. We are trying to live with what we have now even if we completely disagree with everything that’s been done. I suspect if you had to have a light truck to make a living though you’d be more prepared to accept GM’s bailout. Really, it’s not even that. There’s such a huge supply chain that things would be much worse without that bailout. Compared to what we spend for really stupid crap like electrical wind generation, the military, the military, the military and all that entails, it was peanuts. Here in Texas we are booming with oil exploration. There’s a water depot for big rigs seems like every five miles no matter the direction. Soon we can drink oil, bathe with it and eat it if it doesn’t start raining soon. GM’s just another symptom for me, not a life-changer, but maybe a life-changer if it disappeared.

  3. Sorry about the reply to Harry P.’s message, I meant to put it in as a regular comment, not replying to his. This is my comment.

    “You missed a huge point about the cost thing. Yes, the oil will cost more per oil change, but you need to look at the oil change intervals for synthetic oils, either blend or full. The full synthetic oils have a typical interval between 8-10k miles, as per my cars OLM. Comparing this to the interval for non-synthetic of 4-6k. So if it costs 5 dollars more but in the end you do half the oil changes you will save alot of money. I buy a 5 quart jug of Quaker state ultimate durability full synthetic 5w-30 from Walmart for 21 dollars. That’s dexos and full synthetic for only 4 dollars and 20 cents. Lastly then you do get better gas mileage, trust me on this, especially in an older car with many miles on it, make the switch. It’s worth it.”

  4. GM is only doing the bidding of its master – the government, AKA the OBama administration. The government wants American citizens to live more like European citizens, pay the same high taxes, have less, and drive small crappy cars – just look at the new C7 Corvette – it reaks of “European” styling. Still can’t wonder why the Chinese are buying full size GM trucks? it’s the only thing “saving” GM……………just dawned on me, the Chinese will buy GM someday. DUH!

    • Why buy when we (US tax payers) are already paying to move them there, and with a 20 year guarantee of profitability should they mis-manage and loose money. That is what all the Free Trade Agreements is about. Rejoyce, we have been totally sold out comrades

      • Absolutely, Gary.

        “Free trade”is political speech, a slogan. It means: Labor arbitrage for the advantage of multinational corporations, using government force to obtain and enforce that advantage.

  5. When the patent for Dexron III expired, they came out with the new Dex IV. Do some research and you will find a product with little difference. Magical new additives for the new six speed transmissions. Did Dex IV help with the wave plate problem on the six speed. Save some cash if you have a 4l60 or 65 and use Dex III.

  6. On the other hand, if you wouldn’t buy a GM vehicle, and have been using synthetic oil in all your vehicles for years…this dexos deal doesn’t mean a damn thing. 🙂

    • MikeP, exactly. I’ve used Amsoil for a long time and it’s pure synthetics are well above the specs of any manufacturer. If you want to set a dealership straight, they have a number you can call where a rep will line out anybody who thinks they can force you to use a certain oil. But the truth is, so many vehicles made in the last 10-15 years are synthetic engine oil(and other fluids also)specific it doesn’t make a great deal of difference. Watching a race several years ago I heard a commercial say “Mobil 1, the finest oil money can buy”. I immediately noticed this and wondered out loud if I’d missed something since Amsoil puts their oil to tests Mobil 1 refuses to do since they can’t pass them. I learned in the next couple weeks Amsoil had taken Mobil to court and won over this. Mobil probably made enough more money off these commercials that it was a net effect but just the same, had to cease and desist. With Amsoil’s nanotech filters, you can use a by-pass filter and a full flow concurrently on a vehicle and may never had to change oil. And no, I don’t have any affiliation with Amsoil, just have been amazed by their oil and filters.

  7. I sure hope it works out better than DexCool did:


    I had that vile stuff in my 2002 Grand Am. 2 years ago I started smelling burning antifreeze. I figured it was the heater core and since it was summer just put up with it until the fall. When the shop told me the intake gasket was basically gone I started investigating. Turns out they started using synthetic (plastic) gaskets on engines at some point. Apparently they forgot to get with the DexCool department to find out if there’d be any issues. Funny thing… turns out DexCool will destroy synthetic gaskets (whoops!). The shop owner told me he was surprised that it came in on its own power, normally gaskets as bad as this one was would have destroyed the engine.

    GM was found guilty in a class action lawsuit, but you had to have done the repair and file a claim prior to 2008, so I ended up eating the entire cost.

    That, along with the plastic shaft on the power steering pump, the plastic gears on the power windows, and places I drive (the 4 corners area), told me it was time to move on.

    Of course now I have a car that also wants specific fluids, but they are easily found and once the warranty is up there are lots of equivalent substitutes available.

    • I had a 2001 Saturn L100 with the Dexcool. They said to leave it in 5 years or 150,000 miles. I removed the coolant after 100,000 miles and then changed it again at 165,000. Never had a problem even in the intense Florida heat. The coolant never gave me a problem. In fact the cooling system remains intact as I have never even replaced a hose after 200,000 miles. The hoses look good to this day.

      I have heard bad things about Dexcool, but never experienced them.

  8. Manufacturers have had oil specifications for ages, but usually they aren’t branded. They are in part/spec number form. For instance, the Ford spec for 5W-20 is WSS-M2C945-A.

    Two reasons older cars didn’t last so long was due to oil and gasoline of the time. Now there are some issues with particular additives going away but that’s nothing new either. The oil is getting better and that’s a good thing. If a particular additive is too low it’s often sold to add to the oil.

    To older cars there hasn’t been a big problem yet and I don’t think there will be going forward. The improvements in the oil will probably continue to outweigh the loss of the old additives. Furthermore, if there is an issue, rebuilding old engines will result in the substitution of modern materials to make the engines not need the old additives any more. For those already rebuilt it will just be buying a bottle of additive.

    This is all really a non-issue and no different than what’s been done for decades. The added cost of the oil pays back with what it does.

  9. Yeah, thanks for that. I didn’t know about the ‘dexos’.

    If it does turn out to be bad for older cars, hmm, just yet another backdoor way to force older cars off the road?

    One other thought, RE: “a high-quality non-synthetic such as Pennzoil.”

    Hmph, that oil, I’ve thought of that brand as low quality ever since I took an oil pan off a 1970’s Ford truck that had been exclusively run on the stuff for decades, the sludge on the bottom of the pan was like river muck. Ever since then, Pennzoil was last place.

    I’m off to finish watching an old black and white sci-fi film now: The Gamma People.


    So far it seems interesting from a Freedomista perspective and quite relevant to today. You guys might like it for that reason.
    I’m at the part where the behind-the-scenes-controller just ordered the town’s parade to be canceled. The people reacted by tearing down the order and they went ahead with the parade anyway.
    So cool.

    I think I saw a young Clover in the film. The Clover had an epiphany and saw the light. Do you think it;s possible today’s Clover can too? And return to normal, er, shake off the hypnotic effect from nationalism and collectivism.
    I have my doubts.

    • Hi Downshift,

      On the oil: I only mentioned Pennzoil because it’s a known name-brand. I’ve never heard anything to indicate it’s a bum product. But, maybe it is. I’ll look into it.

      On the clovers: We have a live one; see the comments of the badge-licker CNS.

    • No wonder nuclear power is so feared. If Hollywood doesn’t understand it, it must be only for evil uses!

      I wonder if Standard Oil and Gulf put up the money for that piece of trash?

    • The non synthetic Dexos Pennzoil was referred to as that because it is the only one of the premium oil manufacturers on the market that chose to also license a BLEND as opposed to only full synthetics. 1970 huh? You do know that there is NO Pennsylvania Oil in Pennz anymore, right? In fact now the full syn base is made in Qatar.

  10. Nice article, thanks. I just noticed the “dexos” labeling on the new Pennzoil jugs, and I wondered what it meant.

  11. I became well acquainted with zinc content — “ZDDP” — in motor oils when I owned and showed MGs. The little roadsters are all sold now (my motorcycle habit won the day), but I still have a nice stash of Valvoline VR-1 20W50 racing oil on the shelf in the garage.

  12. I woke up this morning feeling like my pockets were gonna get slightly lighter, seems I was right. Thanks for bringing this up, I actually hadn’t heard of Dexos until yesterday wehn a co-worker with a Cruze mentioned it and I inquired further.
    Time to stock up on “good oil” for my ’89 MR2.

    • You missed a huge point about the cost thing. Yes, the oil will cost more per oil change, but you need to look at the oil change intervals for synthetic oils, either blend or full. The full synthetic oils have a typical interval between 8-10k miles, as per my cars OLM. Comparing this to the interval for non-synthetic of 4-6k. So if it costs 5 dollars more but in the end you do half the oil changes you will save alot of money. I buy a 5 quart jug of quaker state ultimate durability full synthetic 5w-30 from walmart for 21 dollars. That’s dexos and full synthetic for only 4 dollars and 20 cents. Lastly then you do get better gas milage, trust me on this, especially in an older car with many miles on it, make the switch. It’s worth it.


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