There's a thread on here somewhere that talks about a custom made car that had about 600 whp in a Dodge Stratus with a Mitsubiushi (sp?) 3.0L and a higher geared tranny. He actually got a bit better mileage out of the car at cruise than before the modification.
[EDIT: After much searching I found it!
http://ecomodder.com/forum/showthrea...omy-14590.html]
If a car has forced induction coupled with higher cruising gears, it can get better mileage. It's also becoming popular for OEM vehicles to be turbocharged and fitted with a smaller engine for economy. Basically if you can make enough hp at very low revs by forced induction, you come out ahead.
You just have to keep your foot out of it
