Recent content by DENNISD

I think this is one of the more balanced posts in the thread because it acknowledges there are many variables affecting engine life, not just viscosity. Where I'd be cautious is the last conclusion. Seeing vehicles that consume oil or are retired before 200,000 miles doesn't necessarily mean...

I agree with your first point. A poorly designed engine or lubrication system can certainly exhibit accelerated wear regardless of the oil used. As for turbocharger manufacturers, their general recommendations are interesting, but they're not a substitute for validating a specific engine. A...

Your examples actually reinforce something I think we agree on: these engines appear to be quite tolerant of adjacent viscosities. A Camry making it to over 200,000 miles on a mix of 0W-20, 5W-20, and 5W-30 is impressive, but to me it demonstrates the robustness of the engine more than the...

I'm all for looking at the numbers. That's exactly why I don't think one UOA can answer the question. If one 0W-20 analysis shows elevated wear, there are dozens of possible explanations besides viscosity—engine break-in, driving conditions, contamination, fuel dilution, sampling variation, OCI...

That's a fair point, and I don't think anyone is arguing that 5W-30 is "too thick" for this engine. Toyota itself approves it in other markets. The question isn't whether the engine can run 5W-30—it clearly can. The question is whether switching from the North American recommendation to 5W-30...

I agree that Toyota doesn't present 5W-30 as some catastrophic choice that will immediately damage the engine or void the warranty. The manuals clearly show the engine is capable of operating on a range of viscosities depending on the market. Where I'd make one clarification is your last point...

I agree. I think we've probably reached the point where we're just going in circles. (well, maybe 18 pages ago) :p There seems to be broad agreement that Toyota approves multiple viscosities globally and that 0W-20, 5W-20, and 5W-30 can all be acceptable depending on the market and operating...

I'm not telling anyone what oil they have to use. I've said repeatedly that if someone wants to run 5W-30 or 0W-30 within Toyota's globally approved viscosity range, that's their decision. What I've challenged are the conclusions being drawn from the data. I have no issue with people posting...

The same thing that guides a lot of owner decisions that fall within an acceptable range: risk tolerance. Some people change oil every 5,000 miles instead of 10,000. Some use premium fuel when regular is permitted. Some replace transmissions fluid earlier than the maintenance schedule. Those...

I completely agree that CAFE may influence Toyota's North American viscosity recommendation. I've never argued that fuel economy regulations play no role in these decisions. Where I think we still differ is that proving CAFE influences the recommendation does not automatically prove that 5W-30...

Honestly, this is one of the more rational takes in the thread. You're acknowledging that it's a personal choice based on climate, operating conditions, and your own comfort level rather than claiming Toyota got it wrong. I don't have any issue with that position. Where I've pushed back is...

Because "not required everywhere" and "superior everywhere" are two completely different things. I've never argued that 0W-20 is the only oil this engine can run. In fact, the global Toyota charts clearly show otherwise. What I keep challenging is the assumption that because Toyota permits...

The funny part is that you actually help me prove my point. If we need a controlled dyno test and teardown to know for sure, then we're probably not as certain about 5W-30's superiority as some people in this thread pretend to be.

I'll watch it, but even if the conclusion is correct for a Duramax, that's still a Duramax-specific conclusion. That's actually been my point throughout this thread. The fact that one manufacturer, one engine family, or one application benefits from a different viscosity doesn't automatically...

Nah... I was just dangling some bait for the forum's greatest minds. Looks like it worked. :idea: