Ktrw
Senior Member
- First Name
- Zach
- Joined
- Mar 25, 2024
- Threads
- 0
- Messages
- 80
- Reaction score
- 141
- Location
- United States
- Vehicle(s)
- 2025 Integra Type S
Yes as I said the oil viscosity is insufficient for the surface finish of the crankshaft, so their band aid fix is a higher viscosity. The root cause was crankshafts that were slightly out of tolerance in dimensions and surface finish but GM determined that 0W-40 would alleviate the problem for effected engines that haven't failed yet, which is a band aid fix. The oil was not the root cause, however, it shows you how thin the margin of success is for a manufacturer recommended specification. 600,000 effected vehicles costing the company billions od dollars, which by their own "fix" potentially could have been avoided with their 0W-40 recommendation that they use for other v8s with similar specs.I thought the root cause was a serious mechanical flaw according to latest studies of the L87 Engine failures. The oil was not the issue - Right? In general, yes thicker oil may provide better protection - depends on the oil - but as we saw in the previous results - it depends on the formulation - and use case. Let's get precise data. Still in search for the best oil. Keep the data coming.
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The K20C engines have higher viscosity recommendations in other countries, so the decision to use 0W-20 is for fuel economy and or emissions, much like GMs decision to use 0W-20 in the L87 when they have other very similar engines that use 0W-40 in the US. Funny how now that 600,000 engines are effected, they recommend 0W-40 but only for those still running basically. Now that they've "fixed" the problem they're saying 0W-20 is fine moving forward. Or you could run a lighter thicker oil, which is in spec for other lower volume vehicles because CAFE, and give yourself some safety margin lol.
I'm all for getting data, and this GM disaster has about 600,000 good data points that costed a few billion dollars.
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