Quote:
Originally Posted by MetroMPG
This isn't rocket science. To start with, the 2012 4.0L V6 has 108 more horsepower than the 3.0L V6 in the 1992 truck: 261 vs 153 (assuming I got the trims right).
Is it reasonable to expect 108 more horsepower to come with no fuel economy penalty? To actually have better fuel economy?
Feel free to carry on the investigation re: vehicle weight, transmission differences & aerodynamics (frontal area is likely greater). |
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.