Mobil1 Euro FS 0w-40 SP, 5100 miles, 02 C5

[jetman]

2002 C5 Corvette coupe automatic, new to me in Feb.2023.

Engine = a stock 2002 5.7L LS1 w/68+k miles as I write this. Sump capacity is 6.5 qts. Premium unleaded. 27+ mpg. Uses 1 qt of oil every 5k miles.

Blackstone Report:
Oil = Mobil 1 0w-40 Euro (SP), 5100 miles in 3 mths. Makeup oil = 1 qt Valvoline PB "Restore" 10w-30. I added it 2100 miles before this sample was taken.

Handwritten center info is about the oil that came in it from previous owner, Mobil1 5w-30, unknown miles on oil, Lab = OAI value report.

Handwritten right side is VOA of the Valvoline PB "Restore" makeup oil.

My only concern from the OAI value report was the Copper, but it trended down in the Blackstone report. Silicon is because I had removed the fuel rail, intake, v& valve covers to replace the oil pressure sender and clean everything up.

I didn't change the oil and/or filter when I took this BS sample. Glad I didn't because oil still looks strong IMO.

As of today I've put another 2200 miles on the oil, 7300 total, and added another 3/4 qt of Valvoline PB "Restore".

I'll send in a sample to OAI when this oil has 10k miles, and get both TAN & TBN.

What say U?

 

[fantastic]

So the results with 39 silicon you're leaving in until 10k?

 

[jetman]

So the results with 39 silicon you're leaving in until 10k?

yes,
from my original post " Silicon is because I had removed the fuel rail, intake, v& valve covers to replace the oil pressure sender and clean everything up".
If you ever done this? a little dirt falls in the engine.

 

[fantastic]

yes,
from my original post " Silicon is because I had removed the fuel rail, intake, v& valve covers to replace the oil pressure sender and clean everything up".
If you ever done this? a little dirt falls in the engine.

Thanks for the clarification! I just wanted to confirm I was reading that right. I understood that it came from the mechanical work. It's just that these 0w-40 oils Si usually avg around 5-7 PPM according to @himemsys VOA Sheet. Using 7 ppm silicon as a VOA guide that would put you at 32 PPM silicon above that.

A standard is no more than 20-25 PPM silicon. Based on that alone I'd replace the oil. But that is your call of course. Just wanted to let you know that it's above what most labs & oil companies would deem "Time to change". The next run should be lower of course if no work will be done & you should be able to resume a longer interval.

I know that's not what you had in mind but wanted to let you have an informed decision. I see that you've already put a few thousand more miles on this oil already. I would be curious how your 10k sample will look. Maybe the oil filter will catch some of this silicon in the meantime. I'll await your next sample.

 

[jetman]

Also, virgin sample of my makeup oil, Valvoline PB "Restore" has 9 of Si.