Question re: Oil Volume and Operating Temperature

A properly designed engine shouldn't have the crank throws getting anywhere close dipping in to the oil level if it's not overfilled per dipstick "full" mark. Engines also have a windage tray in the oil pan, and if properly designed it will help to keep the air "hurricane" caused by the crankshaft and pistons from disturbing the oil in the sump.

I record a few car shows on TV and saw one a month or two ago about more HP with less oil ... I think the show was Engine Masters but not sure.

iirc, they were talking about deeper pans or specially designed pans (windage, etc.) to reduce foaming, etc. and they had some dyno tests with less oil in the crank that showed a little more HP at much higher RPMs. This test was also on one specific engine so who knows.

in general, the hp gains were at VERY high RPMs not applicable to average drivers. Also the HP gains were not that significant. They didn't discuss any potential damage that low oil could cause.

Maybe if you are a race car driver it can help but those guys have specially designed engines anyway.

They also had advertisements about certain oil pans ... In general, I found the show interesting and informative but I put it under "infomercial" category and not applicable to average driver.
 
I drive a lot of short trips at low speed and low stress on the engine. Now that the weather is getting colder it seems that the oil in the sump would take longer to reach operating temp. If I filled the engine with 4 quarts instead of 5 quarts, or maybe even 3.5 quarts, would it get to operating temp quicker than with the full capacity in the sump? Might that not reduce dilution from condensation and fuel dilution, and perhaps provide better protection and less wear?

Most of the time I'm driving only five miles a day, broken into two trips, rarely exceeding 30mph / 1500rpm.
Yes, reducing the sump fill will increase the rate at which the oil heats up. I actually ran tests at GM on the L83 engine on the fuel economy FTP75 cycle at different sump fills. Base engine fill is 8 quarts, and we ran the test at 8, 6, and 4 quart levels. On the 8-quart fill, the oil barely achieved operating temperature by the end of the 44 minute cycle. On the 6 and 4 quart tests, the oil did heat up faster, about 15 minutes faster with 4 quarts. On the 4-quart test, the total fuel consumption was about 1% better than with 8 quarts, due to lower average viscosity during the test.
 
@A_Harman

I assume with 0 quarts the engine would heat up the fastest.
Kidding aside, what was the purpose of your test as far as consumer is concerned? Were they trying to decide the sump size (e.g. 8 vs. 7 or 6 qt)? or a test to figure out the impact or study the side effects of running low on oil?
 
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@A_Harman

I assume with 0 quarts the engine would heat up the fastest.
Kidding aside, what was the purpose of your test as far as consumer is concerned? Were they trying to decide the sump size (e.g. 8 vs. 7 or 6 qt)? or a test to figure out the impact or study the side effects of running low on oil?
The oil level tests were done at the end of a long series of FTP75 tests to show the effects of various advanced technology features in the engine. I had been reviewing the test data all along, and had noted the long oil heat-up period, so I added the reduced sump fill tests at the end. It was kind of disappointing to find out that reducing oil level was almost as effective in fuel economy improvement as any of the advanced technology features we built into the engine. But there was no great interest in reducing sump volume in the production engine (L83 and L86), as their application is trucks, which are subject to hard work in the field.
 
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I'm just trying to figure out how this thread relates to: "Racing Oils/ Engines/Cars/Teams/Drivers"
Going out on a huge limb here and purely guessing: don't racing teams try to fill drivetrain components with the minimum amount of fluid to cut down on weight? Kinda like the old "why use washers just to drag them around a racetrack" thing.
 
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