By Eric Peters, Automotive Columnist
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).
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.
So, you can still use Castrol, Mobil1, Havoline, to name just a few, 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.
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.
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).
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.
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.
One thing’s for sure, though: The cost of changing your car’s oil is going up.