PU 5w30, 6700 miles, 98 Corvette

[Patman]

Here are the latest oil analysis results from my 98 Corvette

Analysis by Wearcheck Canada

6700 miles on oil
Nov 28 to Aug 23 (9 months)
128,600 total miles
Pennzoil Ultra 5w30
Fram Extended Guard oil filter
Vararam cold air kit (with a cotton gauze filter)
LS1 5.7L V8 engine
7.5 qt oil capacity
no makeup oil added
Oil life monitor was at 3%

Iron 35
Lead 3
Aluminum 4
Copper 2
Chromium 1
Tin 1
Silver 0
Titanium 0
Nickel 1

Silicon 14
Potassium 2
Sodium 11
Boron 288
Moly 53
Barium 0
Calcium 3168
Sulfur 2936
Magnesium 13
Phosphorus 599
Zinc 752

Fuel 0
Glycol 0
Water 0

Viscosity at 100c 10.1

This is my second run with Ultra 5w30, and I put in more Ultra 5w30 again, along with a Mobil 1 oil filter this time.

Iron went way up this time! It was only 13ppm for the previous run, which was 6900 miles. It proves my theory that cars that aren't driven everyday will show higher iron in the used oil analysis, due to corrosion. The Corvette is no longer my daily driver, so it often sits for 5-6 days at a time, plus the entire month of February it was in the body shop.

Another interesting thing is the drop in viscosity. With all my PP runs, the viscosity was at 10.9 to 11.0, and my first UOA with Ultra showed 11.2. So it was odd to see this one drop down a full point.

 

[The motor guy]

I haven't seen sulfer before in uoa. Even in the diesel oils they try to limit that stuff to a minimum.

 

[Turk]

My 5.3L GMC Sierra that sat A LOT had Iron at 30, so it's a similar situation, but no Sulfur...

https://bobistheoilguy.com/forums/threads/amsoil-asl-5w30-7-740-miles-2003-gmc-sierra.159363/

 

[Patman]

Originally Posted By: motor_oil_madman
I haven't seen sulfer before in uoa. Even in the diesel oils they try to limit that stuff to a minimum.


Wearcheck is one of the only labs I know of that tests for sulfur, and that number isn't out of line, any UOA I've gotten from them over the past 7-8 years (for many different oils and vehicles) has shown between 2000-3000ppm of sulfur.

 

[tinmanSC]

Originally Posted By: motor_oil_madman
I haven't seen sulfer before in uoa. Even in the diesel oils they try to limit that stuff to a minimum.

Sulfur is a standard element in engine oil, but not many labs test for it. I believe the API allows for 5K ppm max. As Patman said, 2K-3K is normal.
Reference: http://www.pqiamerica.com/testresults3a.html

 

[addyguy]

Patman,

Why was your 'Vette in the body shop? Accident?

 

[CATERHAM]

The Wearcheck KV100 values have always tended to read high in the past so the 10.1cSt value may be a result of finally getting their equipment properly calibrated.
Assuming the reading is now accurate it compares favourably with PU's published value of 10.26cSt.

 

[Patman]

Originally Posted By: CATERHAM
The Wearcheck KV100 values have always tended to read high in the past so the 10.1cSt value may be a result of finally getting their equipment properly calibrated.
Assuming the reading is now accurate it compares favourably with PU's published value of 10.26cSt.



That's an interesting point, and hopefully you are right! I've always thought their numbers seemed a bit higher than they should be, except with the GC used oil analysis, which always seemed to be right on target.

 

[Patman]

Originally Posted By: addyguy
Patman,

Why was your 'Vette in the body shop? Accident?


I was hoping nobody was going to ask me that!

Yes, I did a bonehead move in the beginning of February and gave it too much gas coming out of a mall parking lot, the back end got away from me (still not sure why my traction control didn't kick in!) and I went across two lanes of traffic and smashed into a concrete light pole. Both air bags deployed, the hood and nose of the car were trashed, and it cost almost $10,000 to fix. On the plus side, I had been wanting to repaint the front end for a long time, due to stone chips.

 

[Brons2]

traction control cannot overcome physics!

 

[cchase]

Originally Posted By: Patman
Originally Posted By: addyguy
Patman,

Why was your 'Vette in the body shop? Accident?


I was hoping nobody was going to ask me that!

Yes, I did a bonehead move in the beginning of February and gave it too much gas coming out of a mall parking lot, the back end got away from me (still not sure why my traction control didn't kick in!) and I went across two lanes of traffic and smashed into a concrete light pole. Both air bags deployed, the hood and nose of the car were trashed, and it cost almost $10,000 to fix. On the plus side, I had been wanting to repaint the front end for a long time, due to stone chips.

Ouch. I have noticed that the traction control on my GTO sometimes works, sometimes doesn't (to stop the back end from losing everything), even with electronic throttle.

 

[Patman]

Originally Posted By: Brons2
traction control cannot overcome physics!


Traction control is supposed to stop the tires from spinning though! I wasn't going full throttle, not even half throttle, and even though the road was very cold it wasn't icy. I've had many other situations where the roads were very slick and the traction control kicked in instantly, so it's still a mystery why it didn't help me out here. But yes, I was a bonehead for even giving it half throttle on cold tires on a very cold day. I should have known better.

 

[CATERHAM]

Sorry to hear about you mishap but power sliding through corners is part of the fun of having high powered rear drive sports car.
Keep the traction control and other nanny "driver aids" turned off. How else are you going practice and hone one's car control skills?