Claims at Fuel-Efficiency are a Joke!

I always thought that newer cars were better, as far as gas mileage goes. Obviously, a new truck probably won't have a better mpg than an old compact car, but you know what I mean. Today I was on the government's fuel economy website, and I found that new cars, including most hybrid cars, can't touch my 1991 Geo Metro for fuel economy. After finding the '91 Geo Metro, look for the '07 Prius (the best car, as far a fuel economy). Doesn't it seem like new technology could make an engine much more efficient than one 16 years its senior? I thought so. Who is to blame for this glaring problem? I have no answer.