GM's $1 BILLION Dollar Blunder: ROUGHNESS Matters...

According to the NHTSA, out of spec crankshaft surface finish caused the L87 engine recall, which has affected nearly 900,000 vehicles. In a previous video we detailed how GM is switching from 0W-20 to 0W-40 for engines with these out of spec crankshafts -    • STOP Following OEM Oil Advice (GM Recall P...  . This unfortunate, real world example shows just how important surface texture really is, so in this video we dig into the details of surface texture and how it relates to friction and wear.

Here are some of the videos on my dad's old NASCAR engine:
Honing -    • Greg Anderson Shows You How To Hone An Eng...  
Dyno Testing -    • Can You Gain 300 HP Without Nitrous or Boo...  
Track Testing -    • How to CHOOSE the RIGHT Oil  

Here is the proper framework for making decisions regarding oil.

Step 1 - Utilize the OEM recommended oil and do two early oil changes during the break-in process (500 to 1,000 miles and again between 3,000 and 4,000 miles). If the engine is already broken-in, skip to step 3.

Step 2 - Take used oil samples at each oil change to establish the trend analysis.

Step 3 - Go 5,000 miles on the third oil change and take a used oil sample. If the wear rate per 1,000 miles is below 5 ppm, you are good. If the wear rate is between 5 ppm and 10 ppm per 1,000 miles, go another 5,000 miles on the OEM recommended oil and resample. If the wear rate is still greater than 5 ppm per 1,000 miles, then move to step 4.

Step 4 - Since the OEM recommended oil and viscosity have not produced a wear rate per 1,000 miles lower than 5 ppm, go up to next viscosity grade in the OEM oil. Go 4,000 to 5,000 miles on that oil and then take another sample. See if the change in viscosity drops the wear rate per 1,000 miles below 5 ppm. If it does, you are good. If it does not, then move to Step 5.

Step 5 - Since the change in viscosity did not get the wear rate per 1,000 miles below 5 ppm, try a different brand of oil in the same viscosity grade of whichever oil had the lowest wear rate per 1,000 miles. You will need to use it for 3,000 to 4,000 miles to flush the OEM oil out of the system before going 5,000 miles on the new oil to take another sample. See if the non-OEM oil lowers the wear rate per 1,000 miles to 5 ppm or less. If it does, you are good. You can then use the oil analysis results to fine tune the oil change interval.

If the wear rate per 1,000 miles is still above 5 ppm, try the next higher viscosity oil of that same brand to see if that lowers the wear rate per 1,000 miles. Finding the best oil for an engine is an iterative process, but the data from the samples (viscosity, additive depletion, wear rate) will paint a picture that guides you in the right direction.

For more about Oil Analysis, check out: https://www.speediagnostix.com

Here are links to information related to the recall:
https://static.nhtsa.gov/odi/rcl/2025...
https://gmauthority.com/blog/?s=L87+r...

For a deeper dive into the science of lubrication, check out my good friend Rafe Britton's channel ‪@LubricationExplained‬

To learn more about my dad, check out his interview with Dale Earnhardt Jr:    • How Lake Speed's Journey Went From Karting...  

Who is the ‪@themotoroilgeek‬? I'm a Society of Tribologists and Lubrication Engineers Certified Lubrication Specialist and Oil Monitoring Analyst (I've maintained both of those for over a decade). I also worked for Joe Gibbs Racing for 12 years as their lubricant specialist. During that time, we worked with Wix Filters (one of our sponsors) to test and develop filters for our race engines. We also worked with Lubrizol and Chevron-Phillips Chemical to test and develop oils for our race cars. Following that, I was the head of R&D for Driven Racing Oil. During that time, I formulated and tested over 50 products. We also worked with Cummins, Comp Cams, Oak Ridge National Labs and General Motors on various R&D products. Those efforts are recorded in peer reviewed white papers published by SAE International and ACS Sustainable Chemistry journals. Today, I provide Tribology consulting and used oil analysis via SPEEDiagnostix.

#chevy #motoroil #engine #viscosity #gm #cadillac #gmc