Originally Posted by QuasiMondo

Weight, weight weight. Those 45-50 mpg cars built back then were light, with a curb weight of less than 2000 lbs. The civic hybrid and prius both tip the scales at nearly 3000 lbs, some 300 lbs lighter than the Ford Bronco II of that era. 3000 is the new 2000 and as heavy as these cars weigh nowadays, you'll never get those kinds of numbers without a bit of help from other technologies.