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[ANSWERED] Clear up the oil confusion regarding aftermarket DEXOS 2?

 
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Old 03-01-2019, 01:04 PM
  #21  
Patman
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Originally Posted by AzDave47
Let me clarify, I was talking *F not *C, so even at 20*F, 0W-40 is thicker than 5W-30. 40*C is 100*F+-. Somewhere near or below 0*F the 0W-40 becomes less viscous than 5W-30
I know you meant F, but we're both agreeing on the same thing, that 0w40 won't really offer any cold start benefits over 5w30 until it gets to much colder temps that most C7s will never see. So when GM tries to say they chose to switch to 0w40 for better cold start protection, that's pretty much false.
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Old 03-01-2019, 01:51 PM
  #22  
AzDave47
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Originally Posted by Patman
I know you meant F, but we're both agreeing on the same thing, that 0w40 won't really offer any cold start benefits over 5w30 until it gets to much colder temps that most C7s will never see. So when GM tries to say they chose to switch to 0w40 for better cold start protection, that's pretty much false.
I agree.
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Old 03-02-2019, 08:22 PM
  #23  
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Any high quality synthetic oil would meet Dexos requirements,. the only difference is whether they paid GM to have the label on the bottle. The idea that Mobil 1 is the recommended oil for any reason other than a marketing agreement is silly.Same with Chrysler recommending Penzoil or some other brand I can't think of requiring Castrol. It's all nothing but who had the best offer to be a marketing partner.
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Old 03-02-2019, 09:22 PM
  #24  
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Why would anyone put any oil that is not the recommended in their Corvette, just makes no sense. Don't save money on your oil!!!!!!!!!
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Old 03-02-2019, 09:45 PM
  #25  
AzDave47
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Originally Posted by duanesZ06
Why would anyone put any oil that is not the recommended in their Corvette, just makes no sense. Don't save money on your oil!!!!!!!!!
If you think those that use Amsoil at $9/Qt are doing it to save money, you do different math.

My 09Z has M1 5W-30 recommended, but there is no way I'll run that with 280*F+ road course oil temps. I don't use 15W-50 for the track as I am not going to do an oil change before and after each track day. I use M1 0W-40 which was in Euro delivery Corvettes as Europe doesn't have M1 5W-30 as it cannot be advertised as a synthetic there. My engine builder always uses Amsoil 10W-30 Z-Rod, again not cheap oil.

Can you make sense of that?

Last edited by AzDave47; 03-02-2019 at 09:49 PM.
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Old 03-03-2019, 08:53 AM
  #26  
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Originally Posted by Yamoto
Any high quality synthetic oil would meet Dexos requirements,. the only difference is whether they paid GM to have the label on the bottle. The idea that Mobil 1 is the recommended oil for any reason other than a marketing agreement is silly.Same with Chrysler recommending Penzoil or some other brand I can't think of requiring Castrol. It's all nothing but who had the best offer to be a marketing partner.
Do you honestly think you'll get the same level of performance from Walmart's Supertech synthetic? It is dexos1 certified but I bet you it won't give you the same level of engine cleanliness in the long run as a high quality oil like Mobil 1, Pennzoil or Castrol will.
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Old 03-03-2019, 09:18 AM
  #27  
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Originally Posted by Patman
Do you honestly think you'll get the same level of performance from Walmart's Supertech synthetic? It is dexos1 certified but I bet you it won't give you the same level of engine cleanliness in the long run as a high quality oil like Mobil 1, Pennzoil or Castrol will.
At least early on, some Dealers were just putting generic Dexos oil in our Corvettes and some were trying to upcharge for using Mobil 1 even after GM sent a TIL indicating Corvettes take Mobil 1. If the customer got upcharged, GM would reimburse the Customer.
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Old 03-04-2019, 10:40 PM
  #28  
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I am not happy with Tadge's answer requiring it be above 45F before I can drive my 16 Vette with the factory recommended oil. I do not see this temperature requirement in the owners manual. I am wondering, with this statement, if Tadge is really the qualified person to be answering these questions as he is giving advice that contradicts the factory stated/document requirements.
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Old 03-04-2019, 11:29 PM
  #29  
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Originally Posted by RMS73
I am not happy with Tadge's answer requiring it be above 45F before I can drive my 16 Vette with the factory recommended oil. I do not see this temperature requirement in the owners manual. I am wondering, with this statement, if Tadge is really the qualified person to be answering these questions as he is giving advice that contradicts the factory stated/document requirements.
... but you do know that you are not supposed to drive on the PSC2s when it is below 40*F, right?
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Old 03-04-2019, 11:45 PM
  #30  
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Not everyone drives on the PSC2's. And there is still the temperatures between 40F and 45F.
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Old 03-05-2019, 08:51 AM
  #31  
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The manual guidance on MYs older than 2019 is not a contradiction, and neither was Tadge's advice.. Mobil 1 0W/40 ESP Dexos 2 has only recently been developed, and BGA started filling engines with the new oil in the 19 MY.

It offers better protection on both ends of the temp spectrum, and it's compatible with every MY back to 14. Technology marches on, and when a new and better product comes along, it makes sense to use it. Using 5W-30 is obviously fine for street use, and the engine will almost certainly outlast the the majority of ownership periods.
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Old 03-05-2019, 11:08 AM
  #32  
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Foosh your staement of "Using 5W-30 is obviously fine for street use," is not fine per Tadge's statement. Tadge's statement of "a SAE 5W-30 Dexos1 Gen 2 engine oil may be used for street use above 45F" is about my comment.

Sure 0W-40 will be better than 5w-30 of the same oil family, but some may infer from his statement that 5w-30, as per the manual, is not acceptable for street use.
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Old 03-05-2019, 01:07 PM
  #33  
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Originally Posted by Yamoto
...some other brand I can't think of requiring Castrol.
BMW did. But now they require/recommend Shell.
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Old 03-05-2019, 01:13 PM
  #34  
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Originally Posted by AzDave47
At least early on, some Dealers were just putting generic Dexos oil in our Corvettes and some were trying to upcharge for using Mobil 1 even after GM sent a TIL indicating Corvettes take Mobil 1. If the customer got upcharged, GM would reimburse the Customer.
I know MY dealer put in AC Delco Dexos 1 on my "free" 500 mile post break-in oil change even though the 0W-40 is available and the 5W-30 Mobil 1 is what's "recommended" in the manual. I believe their response to that, when I politely asked, was "you can choose what gets put into the engine when you pay for it."
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Old 03-05-2019, 02:11 PM
  #35  
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Originally Posted by The HACK
I know MY dealer put in AC Delco Dexos 1 on my "free" 500 mile post break-in oil change even though the 0W-40 is available and the 5W-30 Mobil 1 is what's "recommended" in the manual. I believe their response to that, when I politely asked, was "you can choose what gets put into the engine when you pay for it."
That may be your dealer's position but GM says M1 is reimbursed to the dealer, so the dealer is just screwing you.
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Old 03-05-2019, 03:45 PM
  #36  
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Originally Posted by RMS73
Foosh your staement of "Using 5W-30 is obviously fine for street use," is not fine per Tadge's statement. Tadge's statement of "a SAE 5W-30 Dexos1 Gen 2 engine oil may be used for street use above 45F" is about my comment.

Sure 0W-40 will be better than 5w-30 of the same oil family, but some may infer from his statement that 5w-30, as per the manual, is not acceptable for street use.
I see your point. I suspect that was probably a mis-statement. Obviously 5W-30 was fine for use below 45F before 0W-40 became available. I think what was actually meant is 0W-40 is better below 45.
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Old 03-05-2019, 04:56 PM
  #37  
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Originally Posted by Foosh
I see your point. I suspect that was probably a mis-statement. Obviously 5W-30 was fine for use below 45F before 0W-40 became available. I think what was actually meant is 0W-40 is better below 45.
Not true. It is better starting somewhere near 0*F and below, but 0W-40 is more viscus than 5W-30 from above 0* all the way up to 300*+.
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Old 03-06-2019, 04:26 PM
  #38  
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I’m not a petroleum engineer, but today 2/20/19 I took my 2017 2LT Z51 Corvette to Red River Chevrolet in Bossier City, La., for an oil change. VIN 1G1YK3D77H5100920 and when
I asked the Service Rep (Eddie) if the technician used Mobile 1 synthetic oil, he said “no” they used Dexos Full Synthetic. What is “Dexos Full Synthetic”? Is this anything I should be
worried or concerned about? Is this Dexos Full synthetic recommended by GM ? On my oil cap, there is a tag that reads “DEXOS”, not Mobile 1. I understand the GM has dexos
specifications, and now I have to assume that Red River Chevrolet uses this product. Unlicensed product quality and suitability for GM vehicles cannot be guaranteed and, therefore,
use of unlicensed products may result in lower levels of performance and could cause engine damage that may not be covered under warranty. I have 13,074 > miles on my Corvette.
Am I over reacting ? ( see response from Chevrolet Customer Assistance Center...)

Dear Mr. Parsons, Thank you for contacting the Chevrolet Customer Assistance Center. We appreciate you taking the time write us about the recommended oil on your 2017 Chevrolet
Corvette. We understand that you are worried about the performance of the vehicle. We know how important this is to you, and we appreciate you giving us the opportunity to assist.
Dexos full synthetic is safe to use and recommended by GM. Ask for and use engine oils that meet the dexos1™ specification. Engine oils that have been approved by GM as meeting
the dexos1 specification are marked with the dexos1 approved logo. See www.gmdexos.com. Use SAE 5W-30 viscosity grade engine oil.There are many authentic licensed dexos® products
readily available at retail outlets, service repair shops, quick lube operations, and GM service centers. dexos® licensed products are easy to identify. Simply look for the dexos® icon on the
front label and the 11 digit alphanumeric dexos® license number on the back label. Unless an oil package displays these two markings, the engine oil is not an authentic, licensed
dexos®product and is not recommended for use in GM vehicles.
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Old 03-06-2019, 07:05 PM
  #39  
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I went searching unsuccessfully for the letter from GM that specifically indicated Mobil 1 and they reimburse the dealer for M1 on under service warranty cars. Understand that if your car is under service warranty (free oil changes) then GM reimburses the dealer for M1 and the dealer is screwing you if they put in the generic Dexos that they buy in 50 gallon drums.

Last edited by AzDave47; 03-06-2019 at 07:06 PM.
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Old 03-13-2019, 12:59 PM
  #40  
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https://gsi.ext.gm.com/gsi/showDoc.d...044404&from=sm
The 3rd paragraph shows the reimbursement for Mobil 1.
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