For much of the 1990s and 2000s, cars in the US seemed to be suffering an obesity epidemic.  Station wagons bloated into SUVs, compacts swelled into full-sized sedans and even the handful of practically every vehicle managed to grow in size and weight from one generation to the next.

A case in point is BMW’s 3-series.  Once marketed as a compact car for driving enthusiasts, the 3-series of today is more than a foot longer and 600 pounds (25%) heavier than the 3-series of early 1991.  It’s not just a BMW problem.  The Golf may well be the least-changed car stylistically over the past thirty years, but based on the weight you could make two 1979 Golfs from a single 2005 Golf (1750 lbs vs. 3550 lbs).

Fortunately, it looks like one consequence of the largest economic crisis since the Great Depression is that bigger is no longer always better.  The combination of increasing CAFE fuel economy standards and increasing pump prices has finally gotten Detroit and its foreign competitors, not to mention the almighty US consumer, to give some thought to efficiency.

The renewed focus on efficiency has had some very welcome side-effects.  Other things being equal, a lighter car requires less fuel to move.  At the same time, larger displacement engines tend to be less efficient when it comes to fuel consumption.  Since the engine is also one of the heaviest components in the car, this has meant there are considerable gains to be made by building smaller engines.  Meanwhile, improvements in technology have allowed the carmakers to get considerably more power from these smaller engines than were possible ten or even five years ago.

Ford’s upcoming Fiesta ST is a great case in point: the car is a subcompact 5-door hatchback which nonetheless boasts performance considerably better than many luxury models, at a price only slightly north of $20k.  But it can also offer the practicality of being easy to park anywhere and pushing out 35 mpg in real-world driving.  And if you don’t need 0-60 in 6.4 seconds, well, there are plenty of options in the $15k range that are still eminently drivable – something that was certainly not the case five years ago.