Nissan technical review: Development of 0W-8 low-viscosity engine oil for fuel-efficiency improvement

What does the winter rating have to do with it? Are you saying that Mobil 1 or Castrol 0W-40 have nothing to do with engine protection?

The fuel consumption tests are started at room temperature, aren't they? NEDC and WLTP are anyway. So a high viscosity index oil with the lowest possible HTHS would be beneficial. I would expect a 0W-20 to have a higher viscosity index than a 5W-20, a 0W-30 higher than 5W-30, a 0W-40 higher than 5W-40. So it's not really about the winter rating but the oil viscosity from 60°F up
 
The fuel consumption tests are started at room temperature, aren't they? NEDC and WLTP are anyway. So a high viscosity index oil with the lowest possible HTHS would be beneficial. I would expect a 0W-20 to have a higher viscosity index than a 5W-20, a 0W-30 higher than 5W-30, a 0W-40 higher than 5W-40. So it's not really about the winter rating but the oil viscosity from 60°F up
I was just responding to "The 0W-Whatever and 5w-20 oils are ALL ABOUT INCREASING MPG'S IN TEST LABS and nothing to do with engine protection". The 0W-40 oils with numerous manufacturer approvals are all about engine protection. His statement as written was overly broad and false from the standpoint of just happening to be an oil with a 0W winter rating.

The only thing a lowest possible HT/HS oil is beneficial for is fuel economy.
 
Wow! .57% fuel economy! And that is on an engine bolted to a fixture in a lab. Real world would be ZERO IMPROVEMENT.
 
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