BigVette427

Would you run M1's new 0w-40 ESP in your C6 Corvette calling for dexos rated 5w-30? M1 is now calling their new 0w-40 ESP an upgrade to the previous recommendation of their 5w-30 viscosity. 5w-30 to 0w-40 is a big step, usually GM is fairily adament about sticking with one oil viscosity.

What is the better oil if I have no plans to track my Corvette?

If my 6.2L L86 in my Yukon is calling for dexos 0w-20, is this new oil better for it as well, since M1/GM is pointing new LT1's in that direction?

Dirty Howie

Thanks for posting this.
Many of us have been using Mobil1 0w40 for a very long time.
Anybody going to switch from regular 0w40 to the ESP version????


DH

BigVette427

What I don't get is it's almost taboo that an automaker will tell you that you can go from oil viscosity to another. On the trucks where fuel economy is a big deal to the automakers, I can see where they are probably more concerned with EPA fuel mileage ratings than they are the durability (hence the lower powertrain warranty,) and that is why they call for a 0w20 over the previous 5w30 in the LT1's. GM is adament on the 0w20 for the L86 6.2L V8, but it's essentially an LT1 with slightly different intake/exhaust manifolds. Now I'm wondering if I shouldn't be using this new 0w40 ESP?

ESP literally stands for Emission System Protection, which for most Corvette owners is way down the list as to the reasons they bought a Corvette. (Most Corvette guys don't shed a tear at ripping out the mid cats or what not for a little extra power.)

The big difference between this new ESP 0w40 and the currently available 0w40 FS is that the new ESP variant is low SAPS, (sulfated ash, phosphorus, and sulfur.) Note the difference in TBN right off the bat. In modern diesels with diesel particulate filters (DPF's,) low SAPS oils are a must because SAPS plug them up.

In DI engines you have to worry about carbon build up, especially on turbocharged DI engines, so low SAPS there is a must. Not sure how the new Gen V LT motors are handling excess carbon buildup with their DI, and it remains to be seen how supercharged DI engines (LT4) handle excess carbon build up. Note that the new LT5 is GM's first dual DI and PI engine; Ford has been doing this with their 2nd Gen EcoBoost engines for a few years now.

Mordeth

Few things:

1) This information has been widely available for a while.

2) It is not Mobil 1 saying that all Corvettes should use this oil. It is GM, who co-developed/tested it with Mobil 1 that is recommending that this oil is now used as a replacement for M1 5w30 in C7 Corvettes. Tadge Juecter, the Chief Engineer of Corvette already commented on this. This certainly does not mean it cannot be used in a C6 (it is just 0w40 oil with less phosphorous/sulfur and some other agents to help with emissions/cat life and is therefore backwards compatible). However, it is not directly and specifically recommended by Mobil 1 or GM for all Corvettes. (as this thread suggests)

3) Selection of oil, including weight, additives and ZDDP levels are application dependent. 0w40 will provide better cold start protection, and has other positive attributes. Overall, I think this oil will be a good choice.

Here is the ask Tadge thread for those interested: https://www.corvetteforum.com/forums...fill-0w40.html

And attached is a data sheet on the oil from Mobil 1 directly. You will find no mention of C6 Corvettes or LS7s in this data sheet (or any Corvette for that matter).

BigVette427

You missed the point (above in the marketing and below in the YouTube video from the 2018 Rolex 24 Corvette Corral) that they are saying it is recommended for any Corvette that previously called for a dexos rated oil. Backward compatible going back to early 2000's which means C5's.

Check out the 4:40 mark.

Mordeth

It is "backwards compatible" in that it is simply 0w40 oil with a change to the additives. But it was formulated for the emissions systems found in C7 Corvettes. So again, it is simply 0w40 oil. It isn't magic pixy dust.

I am a guy who thinks alot about oil, and my oil is changed pretty much every 2 weeks during the track season. But I don't think there is anything revolutionary going on here. This is simply a refinement to the Euro M1 0w40 to meet current emissions and provide a little bit better cold start protection than 5w30.

BigVette427

Are there really any differences in the emissions between a C6 and C7? M1 could have easily put this new oil under the regular M1 label (already a low SAPS oil as I understand it as far as Sulfated ash and P,) and it would have satisfied Corvette requirements. Why the ESP label?

As far as protection is concerned, particularly in the LS7, which is better - a 5w30 or a 0w40 that covers a broader spectrum?

The big-big thing that I see here is that GM is changing its tune on oil viscosity. I had a diesel Jeep where FCA went from 5w30 to 5w40 after two years of telling folks to run the 5w30, but you don't see this very often and I can't recall an instance of GM doing it before. It can't help but make you think they were perhaps wrong in the past?

As well as their steadfast direction to only use 0w20 in the trucks, where I believe their interests lie more with the EPA than they do the longevity of the motor past 60k miles, (evident with the new shorter warranties.)

At operating temperature (~100°C), the oil in your Corvette with M1's 5w30 is around 11 cSt, but in the new 0w40 it's up to 12.9 cSt. All the more so, how can GM tell you to run 0w20 at 8.7 cSt at 100°C, in the same LT1 motor but in a truck (L86) with slightly different intake/exhaust manifolds and maybe a different ECU tune?

In Texas where it gets in the 100°F realm in the Summer, to me a 0w20 oil sounds inadequate in a 6.2L V8.

Mordeth

Yes there are differences in the emissions systems between model years. And these types of changes occur due to emissions and fuel economy regulations, that get worse (or better depending on who you are asking) each year. Direct injection, active fuel management etc also play a role. Research FE9 Emissions, NE1 Emissions and YF5 Emissions. Also research API SN specs. Often times it fundamentally alters how a car is built, how the PCV system functions, how efficient and durable the catalytic converters are, what fluids are needed and what additives are allowed and at what levels, at what point in the compression stroke fuel enters the combustion chamber and so on. Then it is spun as a marketing tool. The ESP stands for "Emissions System Protection" and was developed and designed on LT1 and LT4 motors found in C7 Corvettes and Camaros that now "require" 0w40. But sure, it could be used on our cars.

I do agree with you that it is interesting that GM is adjusting their stance on viscosity. They basically took M1 0w40 Euro and lowered the phosphorous and zinc to meet emissions and made it dexos2. Euro 0w40 has 1000ppm phosphorous and 1100 ppm zinc. The new ESP 0w40 has 900 ppm phosphorous and 990 ppm zinc. I do wonder though what, if anything they have done to the viscosity improvers. The VIs are how they make 0 weight base stock oil into 0w40. They are important because as the oil heats up it not only loses measured viscosity but it also loses viscosity grade. This means that the oil does not return to its appropriate viscosity when it cools down. So as the viscosity improvers shear down with temp the oil loses its base viscosity grade, which means 0w40 can literally become 0w30 or 0w25 worse. So the quality of the VIs are important and it is why a quality oil should be used. This doesn't typically happen to street driven cars though that don't see oil temps high enough to shear down the improvers.

And to answer your question, for street applications in unmodified LS7s it won't matter whether you use a quality 0w40 or a quality 5w30.
Both will work in my opinion and both will maintain proper viscosity in street applications. But once you start modifying the engine and pushing the oil to temps above 260 degrees in a racing environment it starts to become more critical to maintain higher measured viscosity levels to protect the bearings. It is also important to maintain hydrodynamic lubrication on the bearings. It doesn't matter if it is 100 degrees outside. It matters what is going on inside the engine, what the bearing clearances are, what temperatures the oil reaches, what grade the oil is, the quality of the viscosity improvers, additives and what the ZDDP levels are. The cold start protection is also important. So if you are regularly starting your car in extremely low temps then the 0 grade is likely better. I myself prefer Amsoil, and I have torn my engine down examined the bearings.

SonnyAK

I've been running the M1 0w40 in my '09 for a few years now and have been very happy with it...I'll be sticking with it but will probably keep the original formula as long as it stays available.

MTPZ06

I’ve had M1 0-40 in my 09 C6Z for the last couple years...need to change the oil soon, but I think I’m going Amsoil 5-30.

P.A.J.

I use Mobil1 ESP 0w40 Dexos2 since 2012 in all my GM Models (Opel & Corvette) here in Europe.

Too-Fast

same here, I run the M1 0W40 in mine, switched over three years ago due the high speed events and roll racing.

danziger

I've been using the regular M1 0W-40 for quite a while now. Haven't used the new stuff yet...

Mordeth

Yep. Signature Series 5w30 for you Mike.

LT5 John

Been using M1 0w40 for years...

reasonable suspicion

This is what I've always used. Research had me convinced.

BigVette427

I get what you're saying about the VII's and the rate of which oil begins to break down and longer provide the desired protection. I just came across a cool video earlier in the week where it specifically talked about the ability of a motor oil to maintain it's desired viscosity over the desired span. The video below shows how M1 Annual Protection retains it's viscosity through 20,000 miles, validated by oil samples taken every 5k miles from a test vehicle on mileage accumulation dynamometers. (Around the 17:50 mark)




So help educate me here, please. The big question that I have remaining is, what is the desired viscosity for my street driven Corvette LS7 and Yukon L86 6.2 who's oil temperatures will rarely exceed 100°C for anything more than short durations? Now that it has become apparent that GM was not exactly "on-target" with their 5w30 recommendation all of these years, I'm wondering if I can trust anything they say given as we all know, their allegiance is to the EPA and long-term durability has taken a distant second. (As evident by the shorter powertrain warranty and the fact that we wouldn't be seeing all these things like start/stop and AFM/DOD if they weren't trying to meet chimerical fleet mileage goals set by bureaucrats.) And yes, this acknowledgment is coming from an LS7owner who has paid out of his own pocket to fix the valve guide issue, so I almost feel silly asking if it's okay to F what GM says!

For GM to have gone from 5w30 to 0w40, using M1's published numbers for comparison's sake, they are going from an 11 cSt at 100°C for the M1 5w30 to 12.9 cSt on the new 0w40 ESP. At 40°C, the difference is going from 61.7 cSt to a 69 cSt. Maybe that difference isn't much and if they are both low SAPS oils, maybe the 0w40 is the wiser selection simply because it covers a wider band from 0w out to 40 grade and using modest OCI's, it's a moot point?

And if that is the case, what am I supposed to make of GM's adamant instruction to use ONLY 0w20 in their new trucks, in my case the 6.2L L86 which is virtually identical to the LT1 save for intake/exhaust manifolds and maybe a tune? If it's the same long block as the LT1 and retains the same AFM and DOD, the M1 0w20 AFE, for example, has a much lower 8.7 cSt at 100°C and a very low 44.8 cSt at 40°C. How can GM say to run two such drastic kinematic viscositys in what is essenitally the same engine? Wouldn't the 0w40 ESP be the wiser choice than the 0w20 AFE? I mean, there is no way GM or M1 is going to tell you that it's okay to run 0w20 in your Corvette or Camaro LT1?!

Mordeth

I understand everything you are saying and I appreciate your dedication to the research. However, you are over thinking this for a street driven Corvette. And this is coming from an oil dealer and race car driver who is maniacal about my oil.

For your application (Corvette LS7 with stock bottom end that is street driven) you are safe to use quality oil of 0w40 or 5w30 or 10w30 grades. All provide appropriate viscosity at your operating temp. That said, and to answer your question, it is my opinion that a mostly stock or mildly modified LS7 with stock bearing clearances that is driven regularly on the street prefers a cSt of 10-12 at 212 degrees oil temp. I have no data to back this up, but I have torn apart my own engine and other engines and examined the bearings on both street driven and raced LS7s. Additionally, this is quite literally what the engineers who designed the LS7 (and set the bearing clearances) called for (cSt of ~11 at 212 degrees). Which means a 30 grade oil. You want to argue with them? Once the oil temp rises or falls significantly beyond this number or once the engine is modified then things change. And if GM is changing their mind on C7 Corvettes regarding viscosity then lets wait to see the results. In the meantime, tens of thousands of Corvettes with millions of miles on them are evidence enough for me (as well as personal examination and experience).

Personally, if I were you I would go with Amsoil Signature Series 5w30 or Zrod 10w30. More ZDDP, proper viscosity at both 100 degrees F and 212 degrees F and less pumping friction loss for daily driving due to the 30 weight. And don't be afraid of ZDDP harming your cats. An oil's ZDDP maximum ppm content should be decided by the NOACK Volatility test (percentage) as opposed to the same arbitrary phosohorous ppm cap for all lubricants that API uses. Put it another way, an oil with a high NOACK (>15%) and lower ZDDP could be more harmful to the cats that an oil with a low NOACK and high ZDDP.

So I would look at one of these two oils. Signature 5w30 if the car is mostly stock, street driven and you change the oil once or twice a year. ZRod if your car is modified, driven hard and you change the oil more frequently.

Signature 5w30: 10.3 cSt at 212 F. 59.7 cSt at 104 F. NOACK volatility of 6.7%

Or ZRod 10w30: 11.8 cSt at 212 F. 74.9 cSt at 104F. Higher ZDDP (1320ppm phosphorous and 1440ppm zinc). And NOACK volatility is 5.5%.

By the way, 30 grade oils, by definition, have a measured viscosity range of 9.30-12.49 cSt at 212F. Whereas a 40 grade has a measured viscosity of 12.50-16.29 cSt at 212F. So a 30 grade will typically work better in my opinion for a street driven LS7 that lives most of it's life at ~212 F. The 40 weight becomes better once oil temps go above 260 degrees and is slightly better during extreme cold starts. But again, both weights will work and are a fine choice, if using a quality oil like Mobil or Amsoil. So don't over think this unless you quite literally have nothing better to do or plan to race your car. Pick one and enjoy.

SweetZO6

Bryan91SE

Which oil would hypothetically be better to quiet noisy lifters?