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Has anyone seen or heard of this? dexosD for light duty diesels 0w-20 oil?

Licensed dexosD® brands


Brand NameSupplierSpecificationViscosityLicense NumberRegion
ACDelco Light Duty DieselGeneral MotorsdexosD™0W-20DD0751IA015Global
Mobil Super 3000 XE2ExxonMobil Oil Corp.dexosD™0W-20DD0752IA015Global
 

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Yes, I noticed that showed on on the dexos website when GM is introducing the Duramax 3.0 engine (inline-6) in new vehicles:
1. Chevy & GMC 1500 pickups
2. Chevy and GMC SUVs (Tahoe, Yukon)

The engine is also coming to the Cadillac Escalade, so it will be a return to Cadillac vehicles with a diesel engine! That's the first time since the 1980s!

I think that engine MIGHT also be coming to the Chevy Suburban, maybe. I don't see a reason it wouldn't be an option if it's in all of the above-listed vehicles.

If more oils get added to the list and become available near you, you could probably use them for the Cruze. They are diesel oils that have all the necessary specs for DPF-equipped vehicles, and the lower viscosity might give you better fuel economy. As a 0W-20 you would also get better winter performance if you want to do oil changes on a seasonal basis. Those cold starts from November through about March might go better with a 0W-20 oil instead of a 5W-30.
 

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For a heavy-duty engine (and that can be one in "light duty" pickups), I would avoid 0W-20 oils for a while. The Nissan Titan XD was introduced with an exclusive 5.0 V-8 Cummins diesel engine that used 0W-20 oil. After a notable number of the engines had bearing problems, Nissan changed the oil spec to 5W-30 and that wiped out a lot of the fuel economy advantage of the diesel engine.

That engine was a huge mis-match for the truck it was in, and really isn't a good Cummins product anyways. For the displacement, it doesn't make lots of power. The V-8 is more complicated than an inline-6. And the truck it was in had limited GVWR to where you couldn't effectively use it as if it were a 3/4 ton pickup. No one bought that truck with the Cummins engine other than some posers who wanted a Cummins-powered pickup that wasn't a Ram.
 

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DexosD as mentioned is a spec released for the 3.0L inline 6.

Of course the 0w20 is for fuel economy purposes, the engine goes in only heavy vehicles, and this is just where oil and engines are going, nothing we can really do, except run what we want and hope for the best. No way I'd run 0w20 in my 3.0, I'd be far more likely to run a Dexos2 product and make sure I had receipts for DexosD. DexosD is a low HTHS midSAP oil. Low HTHS oils are designed for fuel efficiency not ultimate protection. I'd be finding a midSAP oil with a higher HTHS and running and monitoring oil temps (LM2 has an actual temp sensor) and as long as I didn't see dramatic oil temp increases, I'd be happy and keep running some 5w30 euro that's much easier to source than DexosD and should protect better.
 

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After reading up on multi-viscosity oil numbers.. you are fine to go lower on the "W" number, as in 0W-30 is FINE, for a 5W-30 spec car, but NOT go lower on the second number, as others have mentioned you put your engine at risk of damage, for maybe a tiny MPG gain. Keep in mind, due to fuel dilution of modern emissions diesels, you likely already are running something with viscosity less than 30 for most of the time, especially close to oil change time. The fuel dilution will lower viscosity over time in even the best oils. One thing to keep in mind, the new 3.0 I6 engine, from what I read has significant improvements in it's emissions system.. for starters it uses POST DPF EGR gas, so much less soot going back through the intake (as in basically NONE), which means far less regens and problems with sticking EGR valves.. now the 6.6L Duramax also does a HC injector in the exhaust for Regens (instead of an 8th post injection event in the cylinder, like the Cruze and most other diesels), that also mitigates fuel dilution, I'm not sure if that is also in the 3.0L but, if it is, that would be even better! Know that your Cruze does not have these fuel dilutions mitigation improvements, and as such your oil is limited by fuel dilution due to post injection events (which is not just during regen, though that is when most fuel is pumped in the post injection mode), and that means you are asking for trouble going long on any oil change, and even more trouble going to a lower viscosity oil.
 

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it uses POST DPF EGR gas, so much less soot going back through the intake (as in basically NONE)
I can't figure out why this wasn't done from the start of DPF-equipped diesel engines. To me (and I'm certainly no professional engineer) it would have been better to take post-DPF exhaust gas to use for EGR. Get rid of as much soot as you can and then put the gas right into the compressor intake so it goes through the intercooler to cool it as much as possible. Maybe you have to upsize the intercooler to get that hot exhaust gas chilled down, but better than the complications of having an engine coolant heat exchanger.
 

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They dont want any exhaust in the intercooler system.
Post DPF EGR flow is only possible on the LM2 due to its packaging envelope. The DPF is close coupled and in the engine bay. And the intercooler is air-water and on the engine .
There's also a pressure difference between pre turbo gas and post DPF gas, and this is part of of the engineering solutions involved in the LM2.
 

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I can't figure out why this wasn't done from the start of DPF-equipped diesel engines. To me (and I'm certainly no professional engineer) it would have been better to take post-DPF exhaust gas to use for EGR. Get rid of as much soot as you can and then put the gas right into the compressor intake so it goes through the intercooler to cool it as much as possible. Maybe you have to upsize the intercooler to get that hot exhaust gas chilled down, but better than the complications of having an engine coolant heat exchanger.
It's all about the $$$. Interesting to note, in places where retrofit emissions were added, like CA (this is all HD and larger vehicle), the post DPF EGR was pretty common. In those cases, there is a different cost dynamic at work. Just think, VW cheated emmissions to save about $300 per car.. Don't think they are the only OEM to make cost driven decisions. You can bet there was an analysis done on cost, and they assumed the cost of under warranty repairs of dirty EGR would be less than the cost of post EGR on vehicles... I should add, most of the dealerships live off the revenue from service (If the vehicles are too reliable and free of service issues, that's another type of economic driver). BTW, another example.. the 3.0 I6 Duramax has a BELT driven OIL PUMP.. that one shocked me frankly, otherwise it looks like a great engine.. but a belt drive OIL PUMP, that is odd, and it requires pulling the transmission to replace, from what I've read! I've come to realize the reality that the OEM looks to make it good enough to get out of warranty in most cases, but not much better.. because of cost. There are certainly ways to make cars more reliable and require less service, but how far do you expect the OEMs will push that envelope? I'm sure there is a limit.
 

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There's also a pressure difference between pre turbo gas and post DPF gas
Isn't the pressure difference beneficial? Pre-turbo is drawing a vacuum and post DPF is positive pressure exhaust, so the turbocharger would be drawing that EGR right into the intake.
 

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the 3.0 I6 Duramax has a BELT driven OIL PUMP.. that one shocked me frankly, otherwise it looks like a great engine.. but a belt drive OIL PUMP, that is odd, and it requires pulling the transmission to replace, from what I've read!
I did research on that. It's fine, really.

The engineers doing the driving of the test engines specified a 180,000 mile interval to change that belt. From their experience with the development engines in the real world, at 180,000 miles there was basically no wear on the belts. Turns out having the belts in the oil sump give them longer life. Ford did something similar with their 1.0 EcoBoost engine (inline-3) where the timing belt is in the oil sump. It's a lifetime belt because timing belts just don't fail nowadays, and the oil keeps the artificial rubber very soft and supple to where it doesn't really wear out. You'll junk a Fiesta or Focus for other issues (primarily rust in the salt belt states!) long before the engine is garbage from the timing belt wearing out.

As for dropping the transmission to change the oil pump drive belt or the timing chain, meh. The Cummins B-series engine has a reputation of longevity and they specify about 180,000 miles as a major service interval, so if you're going to use a GM 1500 pickup with the Duramax engine for real work it will be about 180,000 miles to do major service.
 

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I did research on that. It's fine, really.

The engineers doing the driving of the test engines specified a 180,000 mile interval to change that belt. From their experience with the development engines in the real world, at 180,000 miles there was basically no wear on the belts. Turns out having the belts in the oil sump give them longer life. Ford did something similar with their 1.0 EcoBoost engine (inline-3) where the timing belt is in the oil sump. It's a lifetime belt because timing belts just don't fail nowadays, and the oil keeps the artificial rubber very soft and supple to where it doesn't really wear out. You'll junk a Fiesta or Focus for other issues (primarily rust in the salt belt states!) long before the engine is garbage from the timing belt wearing out.

As for dropping the transmission to change the oil pump drive belt or the timing chain, meh. The Cummins B-series engine has a reputation of longevity and they specify about 180,000 miles as a major service interval, so if you're going to use a GM 1500 pickup with the Duramax engine for real work it will be about 180,000 miles to do major service.
Got me curious about this technology, and found a good article on it here:

That said, I would not push for 180K on one of them in any case.. the Gen 1 Diesel Cruze was supposed to have a "lifetime fill" of AW-1 special transmission fluid.. yeah, about that. at about 45K the cars starts shifting in strange ways, change out the dark as coal thin as water "lifetime" fluid, and it begins to shift well again.. In other words, the OEMs are stretching intervals out quite a bit, some of that is due to better technology, some of it wishful thinking. The Gen 1 auto runs some very high fluid temperatures under normal conditions, there isn't a fluid made that can withstand that for a "lifetime" of the vehicle.

Time will tell how well these belts hold up, but after looking into them, I'd be less concerned about them given what I found.
 

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Got me curious about this technology, and found a good article on it here:
That article says "rubber" at lot in it. Modern timing belts are synthetics that don't degrade like rubber.

Also, it mentions belts snapping. Modern timing belts have things like Kevlar fibers in them and the tensile strength of those is so unbelievably high that belts do not ever snap.

They also say stretching. Kevlar does not stretch.
 

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That article says "rubber" at lot in it. Modern timing belts are synthetics that don't degrade like rubber.

Also, it mentions belts snapping. Modern timing belts have things like Kevlar fibers in them and the tensile strength of those is so unbelievably high that belts do not ever snap.

They also say stretching. Kevlar does not stretch.
Ummm, Did you read the same article I read? The mention of rubber was for old traditional belts and used to demonstrate that change in technology... Read the rest of the article, and perhaps you'll see this supports the use of these new belts... Just saying.
 

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It was the lifetime of the warranty!
Yeah, it might make 60K PT warranty before the transmission was seriously damaged,, might.. but I get your point!
 
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GM had to have known the AF40-6 couldn't go 100k miles or more on factory fill of fluid. It is and was widely known that the Aisin trans doesn't like to go more than 30k before a fluid change. GM just ignored this most likely in order to line it's service intervals up with their practices and the warranty (100k at the time)
 
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