Reducing Drag in an Engine

How, and how does the temp equate to real world numbers?
Too many factors and it would be too difficult to hold all factors constant that effect oil temperature.

What's your goal ... or is this just a mental exercise? 😄
 
Neither. I am just curious to know if there's a way to quantify the amount of drag reduction in an engine by reducing the viscosity or the HT/HS.
There is ... just use what CAFE has told you to use. 😂 There have been studies that try to equate an increase in fuel economy from thinner oils, so that's a way to tell how much friction reduction there is. Also studies that just look at the frictional forces involved between moving parts. Start Googling ... ;)
 
BTW ... there is more to "friction" in an engine than just the shearing friction due to just the oil viscosity. There is also the anti-friction additives in the oil that effects the friction between contacting metal. You could add 150-300 ml of Liqui-Moly Ceratec to the oil and that would decrease the friction between moving parts.
 
We're running thinner oils to reduce drag and increase mileage. Is there some way to measure and understand how much drag is reduced when going to thinner oil? I'm most interested in what happens when going from an HT/HS of 3.5 to something around 3.0, or from a Kinematic Viscosity @ 100 C of 12 to one of 10 or so.
Butt dyno.
 
That's not easy to measure directly.
One approach to estimate it using a dynamometer:
1) Measure fuel flow rate to maintain a specific speed and torque load with test oil #1.
2) Under otherwise identical conditions, including speed, adjust load to yield the same fuel flow rate with test oil #2.
The difference in measured output torque theoretically would equal the difference in drag torque.
Test would have to be repeated a few times to reach a statistically valid conclusion, so it's not a cheap experiment.
 
That's not easy to measure directly.
One approach to estimate it using a dynamometer:
1) Measure fuel flow rate to maintain a specific speed and torque load with test oil #1.
2) Under otherwise identical conditions, including speed, adjust load to yield the same fuel flow rate with test oil #2.
The difference in measured output torque theoretically would equal the difference in drag torque.
Test would have to be repeated a few times to reach a statistically valid conclusion, so it's not a cheap experiment.
why not just compare bsfc with both oils?
 
You're chasing a ghost unless your plan is buy new, then suffer maximum depreciation trading it in to get something else new and in that case, I don't understand the obsession with better fuel economy because even if you are pretending to Save The Planet, the way to do that is not to keep buying new widgets.

Instead, you should appreciate that the trade off is lower drag increases engine wear, within the viscosity recommended or in recent years, to ignore what the manufacturer spec'd for their fuel economy number and just use a sane oil weight for your climate. Nothing extreme.

Some people like to pretend that some engines are magical and can then run a much lighter weight oil due to this magic, but it's not so much the case with modern engines, still mostly comes back to using the weight grade most appropriate for your climate to provide best protection within the environmental range.

I feel like this topic is just rehashing what has been covered 100 times before on BITOG, let alone other sites.
 
Run engines in a closed environment with a prescribed amount of fuel.

A possible example?

A Toyota engine under test load using 0W16 goes 36 minutes and 25 seconds while the same engine on 0W20 goes 36 minutes and 5 seconds on the same amount of fuel.
And both engines will still get lousy gas mileage in slow speed urban traffic. Not enough difference for anyone but the EPA to notice.
 
Do you have a lawnmower?
Change the oil and fill it with what oil you want to test.
Measure out a specific amount of fuel.
Start the engine, full throttle. Time it. When it runs out of fuel, note the time.
Change oil and fill it with the other oil you want to test, repeat test.

To be the most accurate you would need to make three timed runs with each oil for a average.
 
Spintron!
We're running thinner oils to reduce drag and increase mileage. Is there some way to measure and understand how much drag is reduced when going to thinner oil? I'm most interested in what happens when going from an HT/HS of 3.5 to something around 3.0, or from a Kinematic Viscosity @ 100 C of 12 to one of 10 or so.
I'm sure .5 reduction of ht/hs would be significant if a test could be very precise and repeatable. I'll be darned if I know what that is. Although I think it is a legitimate question, Google is your friend.
 
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