I understand your point or question, and I think it's quite reasonable.
I remember that old thread now that you linked it (thanks!), but I don't recall what I'd posted nor why I then deleted it.
Mitch Alsup's point in that thread, and my point here, are the same basic thing: There _appears_ to be a ‘big' difference when we see things like this, but it's small enough to be indistinguishable from, or _maybe_ just above, instrumentation error. In that thread, the test was much closer to what I'd like to see here: Silkolene's racing engine oil compared in two different grades. The 0W20 in that other thread was _not_ the same technology as the other two fluids, and even with _both_ the lower viscosity _and_ the newest technology, the dyno runs didn't show enough difference to overcome instrumentation error (dyno reproducibility).
Things like this happen a LOT— The newest and best technology is applied to a new ‘thing' which is different in multiple ways from the old ‘thing,' but then something other than the new technology is misidentified as _the_ reason for whatever improvement. The conflation of multiple factors means the test isn't actually testing a single factor, and piled on top of that is the fact that there's neither disclosure nor discussion of testing or instrumentation error.
To be clear: Lower-viscosity fluids require less power to pump and flow, therefore they save fuel, just as newer-technology lubes can reduce both wear and power loss vs older-tech ones.
All I'm saying is that the magnitude of the savings between a same-tech 5w20 and 0w20 on a dyno is nowhere near what one might infer from the comparison in this thread.
I remember that old thread now that you linked it (thanks!), but I don't recall what I'd posted nor why I then deleted it.
Mitch Alsup's point in that thread, and my point here, are the same basic thing: There _appears_ to be a ‘big' difference when we see things like this, but it's small enough to be indistinguishable from, or _maybe_ just above, instrumentation error. In that thread, the test was much closer to what I'd like to see here: Silkolene's racing engine oil compared in two different grades. The 0W20 in that other thread was _not_ the same technology as the other two fluids, and even with _both_ the lower viscosity _and_ the newest technology, the dyno runs didn't show enough difference to overcome instrumentation error (dyno reproducibility).
Things like this happen a LOT— The newest and best technology is applied to a new ‘thing' which is different in multiple ways from the old ‘thing,' but then something other than the new technology is misidentified as _the_ reason for whatever improvement. The conflation of multiple factors means the test isn't actually testing a single factor, and piled on top of that is the fact that there's neither disclosure nor discussion of testing or instrumentation error.
To be clear: Lower-viscosity fluids require less power to pump and flow, therefore they save fuel, just as newer-technology lubes can reduce both wear and power loss vs older-tech ones.
All I'm saying is that the magnitude of the savings between a same-tech 5w20 and 0w20 on a dyno is nowhere near what one might infer from the comparison in this thread.