2017 Corvette / Mobil 1 ESP 0w40 / 7.1k miles

Messages
13,616
Location
Frisco, TX
This is the third full interval with the M1 ESP Formula 0w40. I pushed it past my usual 20% OLM reading and let it go down to around 3% which was around 2k extra miles. But this also worked out to a lot of track time: about 15 hours! Several of those track days had ambient temps in the mid-90s but overall oil temps and pressures stayed steady. Never got oil temps above 265 F. Blackstone said that overall it looked good, but again noted the viscosity was a bit low. I've since switched to Motul 300V 0w40 which I hope holds its viscosity a little better. I'm still really impressed with how this thing continues to hum along without any major issues despite the hard driving. I just had it dynoed last month and it laid down 400whp, meaning it's still producing the claimed 460 crank hp (if you assume 15% drivetrain loss).
Code
OIL             M1 ESP 0w40  M1 ESP 0w40  M1 ESP 0w40  M1 5w30  M1 5w30  M1 5w30
MILES IN USE    7,095        5,230        5,915        3,848    5,651    741     
MILES           28,480       21,385       16,155       10,240   6,392    741   
SAMPLE TAKEN    3/24/20      9/13/19      2/26/19      6/22/18  9/22/17  4/12/17  

ALUMINUM        5            5            6            6        10       3        
CHROMIUM        1            1            1            1        2        1        
IRON            21           18           35           34       53       48       
COPPER          2            3            3            5        13       28       
LEAD            0            2            1            1        1        1       
TIN             0            0            0            0        0        0        
MOLYBDENUM      70           66           69           80       76       84       
NICKEL          0            0            0            0        0        0        
MANGANESE       0            0            0            1        2        2        
SILVER          0            0            0            0        0        0        
TITANIUM        0            0            0            0        0        0        
POTASSIUM       1            2            1            2        5        10       
BORON           178          175          156          66       54       106       
SILICON         7            7            10           12       40       74        
SODIUM          4            4            7            4        5        7       
CALCIUM         1515         1441         1539         1103     956      1043     
MAGNESIUM       16           30           119          779      682      624      
PHOSPHORUS      744          719          769          735      627      692      
ZINC            830          798          801          819      733      753     
BARIUM          0            0            0            0        0        0
     
INSOLUBLES      0.2          0.1          0.1          0.1      0.1      -      
WATER           0            0            0            0        0        0        
FLASHPOINT �F  395          410          390          395      390      SHORT      
SUS VIS 210�F  61.5         64.4         62.5         56.8     54.8     -
cSt @ 212�F    10.65        11.44        10.92        9.29     8.71     SHORT
TBN             2.6          3.6          2.8          4.4      4.6      6.2
TAN             4.6          4.6          3.7          2.8      4.7      1.9


 

dparm

Thread starter
Messages
13,616
Location
Frisco, TX
Originally Posted by tcp71
Isn't it supposed to be bad if the TAN number exceeds the TBN number?
The answer is: it depends. Some oils will have a high starting TAN, so without knowing the virgin (brand new out of the bottle) TBN and TAN, you can't definitively say that oil must be changed when TAN > TBN. That being said, I don't think the oil I used has a naturally high TAN. Some deeper discussion on the subject: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1970704/TBN/TAN_CrossOver_in_UOA--_Wha
 
Messages
34,057
Location
Southern NJ
Looks really good, especially with 15 hours of track time. Wear control is excellent. Regarding viscosity, Mobil has to be aware that their 0w40 drops into 30 grade territory. It always has. The HT/HS of this oil is around 3.6. In order to prevent this, one could go with Redline 0w40 which has a HT/HS of 4.2, but it's not good for LSPI issues. Mobil did 2 years worth of testing with this oil for this car. I would absolutely stay with it.
 
Messages
8,048
Location
Michigan
Fuel dilution? I see your UOA lab doesn't provide a fuel dilution measurement. I doubt that the oil is shearing in a GM LS-type engine. In hot trackday conditions, I wouldn't be surprised if the ECM calibration is injecting a lot of extra fuel to save the cats.
 
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dparm

Thread starter
Messages
13,616
Location
Frisco, TX
Originally Posted by A_Harman
Fuel dilution? I see your UOA lab doesn't provide a fuel dilution measurement. I doubt that the oil is shearing in a GM LS-type engine. In hot trackday conditions, I wouldn't be surprised if the ECM calibration is injecting a lot of extra fuel to save the cats.
Forgot to include it, but yes, Blackstone provides fuel numbers. It's been <0.5% every time.
 
Messages
15
Location
Michigan
Thanks for this! Was considering amsoil signature series or the new factory fill. I also have a 17 Grand sport. My LT1 has a supercharger added, so I am particularly interested in protecting the motor as it doesn't come stock with boost smile
 
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Messages
15
Location
Michigan

Patman

Staff member
Messages
21,990
Location
Oakville, Ontario
The wear numbers are good but something always bothers me about an oil that loses that much viscosity, I figure that in the long run that means the engine might not be as clean inside, as the thinning is the breaking down of the VII. I'm very glad I'm sticking with the 5w30 version of ESP Formula, it stuck at it's starting viscosity of 12.1 for my entire 7200 mile interval on my last UOA.
 
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