There's no getting around it:We live in a tough new world of $4 per gallon gasoline, and a U.S. economy that has its share of difficulties — with no signs of relief coming anytime soon. But enthusiasts still need to have fun, right? Right! Luckily, small turbocharged engines make sense, as they offer decent fuel economy when driven like Grandma — the Chevrolet Cobalt SS, for example, gets an EPA-rated 30 mpg on the highway — along with kick-in-the-pants acceleration that'll make Prius owners 'green' with envy when you get playful with that right-most pedal. Add in that all four cars here start at under $27,000, and you can see we just might be on to something