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You are telling us that you cannot perform your own experiment because there is NO place to coast to a stop from 30 anywhere around you? with engine braking even? That is remarkable in itself
P.S. PLEASE don't EOC in gear if you have a carburetor, yall.
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Oh, I did, but the streets weren't empty enough to really take any meaningful measurements.
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Pumping losses are only a significant issue when the engine is making power AFAIK. I've asked, and been told there is no significant difference when coasting in gear/engine off between throttle open and closed FWIW.
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So for engine-off, closed throttle:
1. - The intake stroke works against the vacuum
2. + The vacuum returns the power on the compression stroke.
3. - Vacuum works against the the combustion stroke.
4. 0 Exhaust valve opens when chamber contents are about equal to what the manifold pressure was, air rushes in through the exhaust valve and gets pumped back out on the exhaust stroke.
Net effect: -1
For engine-off WOT:
1. 0 Intake stroke freely sucks in air.
2. - Compression stroke compresses the air.
3. + Combustion stroke, pushed down by compressed air.
4. 0 Exhaust stroke, atmospheric air is evacuated.
Net effect: 0