Dexos 2 discontinued in 2025

[DanDeLaVega]

Web link. Saw the following on the GM Dexos website:
“Please note: GM dexos 2 is being discontinued in 2025 and replaced by GM dexos D and GM dexos R. Vehicles equipped with diesel engines that used GM dexos 2 engine oil will use GM dexos D licensed engine oils, while vehicles equipped with gasoline engines will use GM dexos R licensed engine oils of the of the appropriate viscosity grade at their next oil change.”

I’m curious to see how Dexos D gets used in applications where an xW-30/xW-40 Dexos 2 was original spec. Maybe GM will allow the higher viscosities for D. That might be interesting to the 3.0 Duramax owners looking for a D approved oil but want more viscosity than 0W-20.

 

[ctechbob]

Makes sense. The old ratings were confusing. Dexos 2 has to be better than Dexos 1 right?

 

[DanDeLaVega]

Makes sense. The old ratings were confusing. Dexos 2 has to be better than Dexos 1 right?

Yes, confusing. And to think, someone in marketing got paid to create that. And then however many years later, someone else in marketing got paid to work up the transition over to DexosD.

I will say, it’s still easier than most everyone else’s jumble of letters. Ford WSS-1234-C-3PO, and I’m a Ford guy!

 

[ctechbob]

Yes, confusing. And to think, someone in marketing got paid to create that. And then however many years later, someone else in marketing got paid to work up the transition over to DexosD.

I will say, it’s still easier than most everyone else’s jumble of letters. Ford WSS-1234-C-3PO, and I’m a Ford guy!

Tell me about it, my Ranger owners manual has a spec in it that you can't find anywhere and you have to dig deep to realize that the new spec is just fine to use. I'm sure they sent a fax out to their dealers somewhere that told them that.

 

[ATex7239]

I guess Dexos D for diesel and Dexos G or P for gasoline or petrol would have been too easy and straightforward… They just had to throw an R in there so people can think it is racing oil or something.

 

[79Subaru]

In Europe, the Opel 1.6 diesel (Cruze 1.6 diesel in the US) oil spec was changed from 5W-30 to 0W-20 because of timing chain tensioner issues. Not enough oil flow in low pressure mode to put enough pressure on a worn out die cast tensioner. The fix in Europe was change the tensioner, add a special gasket behind it that holds oil in on shutdown, and change to 0w-20 oil (not Dexos D but a different similar Opel spec with a long number because this was after Opel was bought by PSA). And this seemed to fix the issues with that tensioner. I repaired one in the US where I did a similar thing. I ordered the gasket from Europe, but I used a 3.0 Duramax lower timing chain tensioner, which is the same size but much better quality and materials. I also changed the oil cap for the 3.0 Duramax one that says Dexos D and recommended Amsoil 0W20 diesel oil. Still running now, 50,000 miles later. Used oil analysis over the entire time period didn't look any worse than with 5w30 Dexos 2. He also used some FA-4 5w-30 with similar results, it is not that different viscosity wise from the Amsoil after all. So I wouldn't doubt that at least for that engine, that the spec wouldn't just change to 0W-20. That engine does fine on it. In Europe they are running even thinner oils in the same engine, equivalent to Mobil 1 ESP X2 0W-20 or thinner. Doesn't seem to affect longevity and even seems to prolong the life of the timing chain tensioner.

 

[kschachn]

In Europe, the Opel 1.6 diesel (Cruze 1.6 diesel in the US) oil spec was changed from 5W-30 to 0W-20 because of timing chain tensioner issues. Not enough oil flow in low pressure mode to put enough pressure on a worn out die cast tensioner. The fix in Europe was change the tensioner, add a special gasket behind it that holds oil in on shutdown, and change to 0w-20 oil (not Dexos D but a different similar Opel spec with a long number because this was after Opel was bought by PSA). And this seemed to fix the issues with that tensioner. I repaired one in the US where I did a similar thing. I ordered the gasket from Europe, but I used a 3.0 Duramax lower timing chain tensioner, which is the same size but much better quality and materials. I also changed the oil cap for the 3.0 Duramax one that says Dexos D and recommended Amsoil 0W20 diesel oil. Still running now, 50,000 miles later. Used oil analysis over the entire time period didn't look any worse than with 5w30 Dexos 2. He also used some FA-4 5w-30 with similar results, it is not that different viscosity wise from the Amsoil after all. So I wouldn't doubt that at least for that engine, that the spec wouldn't just change to 0W-20. That engine does fine on it. In Europe they are running even thinner oils in the same engine, equivalent to Mobil 1 ESP X2 0W-20 or thinner. Doesn't seem to affect longevity and even seems to prolong the life of the timing chain tensioner.

That makes no sense. Flow is not dependent on viscosity and pressure is higher with a greater viscosity.

And grade isn't a "spec".

 

[79Subaru]

That makes no sense. Flow is not dependent on viscosity and pressure is higher with a greater viscosity.

And grade isn't a "spec".

Variable displacement oil pump. ECU varies cavity size in the pump to maintain a certain pressure. Thinner oil, more flow to maintain the same pressure. And I didn't mean the grade when I said Opels spec. I meant Opel OV0401547 spec, which is similar to US Dexos D.

 

[kschachn]

Variable displacement oil pump. ECU varies cavity size in the pump to maintain a certain pressure. Thinner oil, more flow to maintain the same pressure. And I didn't mean the grade when I said Opels spec. I meant Opel OV0401547 spec, which is similar to US Dexos D.

Yes the old "thinner oil is required because of the variable output pump". How is the output controlled?

Must be heck in cold weather with failures everywhere.

 

[bmwtechguy]

Would there be any disadvantage other than slightly lower fuel economy using a high quality 5W-30 Dexos D oil in the 3.0 Duramax vs the factory recommended 0W-20 Dexos D? It had dealer oil changes at 5 or 6000 miles with factory recommended oil while under warranty. It's in South Carolina year round, so it gets slightly below freezing only a couple three months per year. I'm a bit concerned about using such a low viscosity oil 0W-20 in such a powerful engine, especially when worked hard in hot weather on 95-100 degrees F days.

 

[Bill7]

Would there be any disadvantage other than slightly lower fuel economy using a high quality 5W-30 Dexos D oil in the 3.0 Duramax vs the factory recommended 0W-20 Dexos D? It had dealer oil changes at 5 or 6000 miles with factory recommended oil while under warranty. It's in South Carolina year round, so it gets slightly below freezing only a couple three months per year. I'm a bit concerned about using such a low viscosity oil 0W-20 in such a powerful engine, especially when worked hard in hot weather on 95-100 degrees F days.

If you google: "HTHS wear chart", it becomes obvious that higher HTHS oils protect better.
About 3 years ago I switched to 5W-30 oil for all my vehicles, even though the owner's manual specs the vehicles for 20 weight oils.
Higher HTHS oils (HTHS 3.1+) are the only oils I will ever use. HTHS 3.5+ oils protect the best, such as any Euro oil with ACEA C3 or A3/B4 spec. If your vehicle burns oil, I would use an ACEA C3 oil which is lower in phosphorous. If your vehicle doesn't burn oil, then an ACEA A3/B4 oil might be best due to it's increased phosphorous / zinc anti-wear additives.

 

[edyvw]

Variable displacement oil pump. ECU varies cavity size in the pump to maintain a certain pressure. Thinner oil, more flow to maintain the same pressure. And I didn't mean the grade when I said Opels spec. I meant Opel OV0401547 spec, which is similar to US Dexos D.

I would say there is more to it regarding additive composition.
What PSA did was band aid at the expense of the life of an engine.

 

[53' Stude]

Makes sense. The old ratings were confusing. Dexos 2 has to be better than Dexos 1 right?

DEXOS 1 is for gas engines. DEXOS 2 is for diesel

 

[Pablo]

I thought Dexos D already exists?? I clearly admit I don't baby sit these specifications.

https://amsoilcontent.com/ams/lit/databulletins/g3713.pdf?zo=515729

 

[Bailes1992]

Variable displacement oil pump. ECU varies cavity size in the pump to maintain a certain pressure. Thinner oil, more flow to maintain the same pressure. And I didn't mean the grade when I said Opels spec. I meant Opel OV0401547 spec, which is similar to US Dexos D.

The change to OV0401547 was just down to PSA's acquisition of Opel/Vauxhall and nothing to do with the tensioner on the 1.6CDTi engine.

I bought a brand new 2021 Vauxhall Insignia 1.5CDTi that had been sat in a dealer lot for over 6 months before I bought it that specified a 0w20 Dexos D oil. My colleague around 8 months later had a new Insignia 1.5CDTi as a company car and his specified a 0w20 OV0401547 oil. Same engine, same car.

 

[DerFahrer]

Isn't the only GM car that requires Dexos R is the C8 Corvette? I believe it is Mobil 1 ESP 0w 40. Correct me if I'm wrong???

 

[DanDeLaVega]

DEXOS 1 is for gas engines. DEXOS 2 is for diesel

I’m not 100% sure, but I think his comment was meant to prove the point that Dexos 1 vs 2 is confusing. You can’t tell that 2 is diesel & 1 is gas based on the name. At least Dexos D makes you stop and think “what’s the D for?” Then that average Joe customer reads the bottle a little closer to see it’s for diesel engines.

 

[Cary]

I’m not 100% sure, but I think his comment was meant to prove the point that Dexos 1 vs 2 is confusing. You can’t tell that 2 is diesel & 1 is gas based on the name. At least Dexos D makes you stop and think “what’s the D for?” Then that average Joe customer reads the bottle a little closer to see it’s for diesel engines.

Imagine if they got really creative and named it “Dexos Diesel” or canned the marketing people and called it “GM Approved Diesel Oil”.

 

[53' Stude]

I’m not 100% sure, but I think his comment was meant to prove the point that Dexos 1 vs 2 is confusing. You can’t tell that 2 is diesel & 1 is gas based on the name. At least Dexos D makes you stop and think “what’s the D for?” Then that average Joe customer reads the bottle a little closer to see it’s for diesel engines.

Dunno, this is all confusing. My jug of M1 0w30 AFE says clearly DEXOS 1 GEN 3 and meets API SP


Only oil I have saw that is DEXOS 2 (which again, is for DIESEL engines is PP EURO L 5w30. Please, let’s not confuse the two.


Thank You

 

[53' Stude]

This will make it so simple it’s not even funny.

Dexos 1 vs Dexos 2 Engine Oil: 7 Key Differences - MrOilGuy

Explore the vital contrasts between Dexos 1 and Dexos 2 engine oils. Understand what sets them apart and decide which is best for your vehicle.

mroilguy.com