Amazing, Chevy builds a 330 HP engine with 28mpg Options

[Hawktel]

So the new Impalla that chevy has released has a option for a 330 HP V8 with 28 highway fuel consumption.

Thats amazing. Just amazing. I wonder how far fuel efficency can be pushed?

[phantom914]

Jim,

Makes sense. If an engine had individual drive-by-wire throttles, would it be simpler to switch those out (closed) rather than the valves? And what if there were similar butterfly or other type of valves on the exhaust side. Wouldn't it be less complex than deactivating the valvetrain? Or if not less complex, would it work? I think it wouldn't work as well since the butterfly valves woudn't seal as well as a closed cylinder-head valve. I am just curious whether you think it would work at all since that would seem to address the pumping loss issues you mention. Don't think that I was thinking of trying it.....(IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) .....this year... (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) ... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

I do still think (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) that (maybe?) a fuller cylinder will burn more efficiently. It is harder to ignite and sustain ignition in a partially filled cylinder compared to a more fully filled one. I don't know the exact mechanism(s), but the pressure developed before and after ignition, heat generated by combustion and heat rate lost to cylinder walls etc affect ease of starting/sustaining combustion and also energy output/efficiency. (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) Some of these factors would be affected by the amount of cylinder filling, wouldn't they?

Also, a car will get better mileage with higher gearing. Which of these factors are significant: 1) less frictional loss due to engine turning fewer revs over a given distance2) less pumping loss due to higher throttle opening 3) increased efficiency due to greater cylinder filling 4) any thing I didn't mention.

Is that too many questions? (oops, that was another one)


(IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Andrew