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Old 04-03-2012, 06:44 AM   #40 (permalink)
Tesla
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Join Date: Feb 2012
Location: Australia
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The Truck - '02 Nissan GU Patrol ST
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Quote:
Originally Posted by serialk11r View Post
Remember, if the engine speed is lower, the volumetric efficiency at the same throttle position will be higher, because the pressure drop is lower across the same throttle plate if the air is moving by slower. However when you are accelerating, that is the perfect chance to open up the engine and operate it at higher efficiency levels, so you don't want to feather the gas while accelerating.
So what you are saying is basically the same as I wrote a couple of posts up, although mine is a Diesel, this is what I have generally done with most vehicles I drive.
I have a question though, how does this relate to the concept of using a vacuum gauge on gas engines as an economy gauge, i.e. higher vacuum, better economy?
Surely running in a higher gear with low engine speed and a more open throttle would result in lower vacuum & hence lower economy, only one concept can be right.
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