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Old 09-18-2012, 10:44 AM   #42 (permalink)
Daox
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Quote:
Originally Posted by DoctorM View Post
Thanks for the spec link. I was just about to go look for that.

Vehicles generally don't operate at their peak horsepower. For a given total load on the engines, at the same speed, both have to produce close to the same horsepower (internal work will match external work -- load x speed = horsepower, in the right units). The same horsepower expended should consume close to the same fuel quantity.

Where you get into differences is that the higher horsepower engine has the capability to either pull a much heavier load at the same speed, or pull the same load at a much higher speed, in which case the higher horsepower engine will of course consume more fuel. For running about in town lightly loaded, the larger engine should up-shift much quicker than the smaller engine. Whether it really does or not would be something to test, though I no longer have the '92 to compare directly.
You should read about brake specific fuel consumption and how it effects engines and efficiency. That should clarify things as to why a 4.0L with over 100 more horsepower gets worse gas mileage than a 3.0L engine.

You seem to be disregarding all of our advise as if you have all the answers, yet all you seem to have is questions with no answers. We have been doing this for FAR longer than you. It might be worth considering that our experience has shown us and taught us things that you don't know yet.
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