Valvoline VR1 Racing Full Synthetic 20W50, 2.3k mi OCI, 9.5k mi, C7 Corvette Z06

Apr 9, 2013
Philadelphia, PA
This is the fourth sample in the current OCI. If you take a look below and see the Valvoline UOAs they are all from the same OCI. I keep sampling after track events. Another thing to note is that I keep adding top-up oil which actually refreshes the oil's viscosity, additive package, and also lowers fuel dilution and oxidation present. In my mind, that means I can actually run a longer OCI since I am effectively changing the oil every 5 track events. I don't think replenishing the oil lowers the wear metals (either absolute or relative terms) since the oil that burns up is replaced to the same level and I assume the wear metals themselves don't burn up, so the ppm figures stay the same (total # of particles / oil volume). If that's wrong, let me know. I will be changing the oil soon since I am upgrading the oil cooler. I will try Driven DI50 and Red Line 15W50 and then see which one does best.

Using results from my VOA, it appear that Mobil1 15W-50 actually sheared much worse when compared to any of the VR1 UOAs. Previous UOAs from this OCI are in this thread.

Notes from report:
-9496 miles, 216 engine hours on engine
-2288 miles (street+track), 48 engine hours (street+track) on current OCI

-Took oil sample with vacuum pump through dry sump dipstick tube after a few hundred miles of track driving and associated street driving (while towing a light tire trailer). Oil temperature when sampling was around 185-195F. Added two quarts of top-up oil. Engine was idled about 5 seconds before being shut off. I waited around 5-10 min after engine shutdown before taking sample. Since last sample I've added 1073 miles (800 street miles, 200 track miles), 20 engine hours (with 6 of those as track engine hours over 3 track days). However, I did not change the oil so it's cumulative with the other Valvoline UOAs.

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