[JacobAziza]

I thought for sure someone would have asked this already, but nothing turned up in the search...

My understanding is that the whole reason pulse and glide improves mpgs is because during acceleration the throttle plate is open, reducing the force needed to suck air past it, otherwise known as "pumping losses".

A diesel regulates power by injecting less fuel, and always has an unrestricted air supply (which is why it has no vacuum and therefor needs a separate vacuum pump to run the brakes).

Therefor, not having any throttle plate, and therefor no pumping losses, it seems P&G should provide no benefit at all the diesel vehicles (aside from when coasting because of hills or red lights) - in fact, I imagine it would result in slightly worse fuel economy, due to the extra force required to accelerate.

Anything I am not factoring in? Any data or theory to support or counter that P&G might be effective in diesel vehicles?