[mwebb]

1.pumping losses are not Insignificant in gasoline engines
2. variable vane turbos have been in production and use in VWs for many years
3.gasoline engines with direct injection still use throttle plates or variable lift intake valve to control air flow to the intake and by so doing
MUST have suction throttling loss es / pumping losses

AFR in gasoline engines is controlled to be near 14.7 to 1 much but not all of the time in direct injection gasoline engine systems and it could NOT be controlled if air flow were to be UN controlled as it is in a older diesel engine / remembering that air flow is regulated / controlled in newer diesel systems by a
throttle plate , primarily used to
increase EGR flow by increasing pressure delta betwixt exhaust and intake ,
also
throttle plate is used to stop the diesel engine right now when key is switched to off in current production diesel engines with direct injection, assuming there is a "key" .

the throttle plate in newer diesel engines does increase pumping losses / suction throttling loss and the throttle plate in the exhaust (also used to increase EGR flow ) does not help in that regard either

to winterize

Originally Posted by drmiller100

To summarize, the members are arguing pumping losses are insignificant for a gasoline engine, and turbo chargers work off of only the mass of the exhaust gasses passing through them (and heat doesn't matter), and variable vane turbos are too far in the future to be worth worrying about.