SUV reduxUntil the second half of the 2000s, big SUVs were undisputed road royalty in the United States. But then Katrina and her sisters made gas prices spike by destroying oil infrastructure in the Gulf of Mexico and the Great Financial Crisis made the economy tank, forcing a lot of people to downsize. Add to the mix new CAFE fuel economy regulations that, for the first time in a loooong time, forced automakers to make a bigger effort to boost the MPG numbers of their vehicles, and it looked like we were really moving in the right direction.
But there's now a new wave of SUV revival going on. For the first time in many years, more people are buying SUVs than sedans. This is partly because the economy is also reviving, and to many people "bigger = better". But it's also because many modern SUVs are more car-based than truck-based, and benefit from powertrain improvements that allow them to get MPG numbers not too dissimilar from large sedans (f.ex. Ford Escape 26 MPG combined, Ford Fusion 28 MPG combined).
But is that good enough?
Only if you compare to the previous generation of SUVs. But the real choice today isn't between old and new SUVs, it's between a number of other alternatives that are also much improved. The rest of the field hasn't been standing still. The general principle remains the same: If you need to drive (and not everybody does - it's better to walk, bike, or take transit, but not everybody can, especially in rural areas), you should get the most efficient vehicle that meets your needs. Some people might need the extra functionality of SUVs, but most people probably don't. Today the cleanest vehicles are electric cars and plug-in hybrids, options that weren't on the market in the early 2000s.
So even if a shiny new SUV gets 25 MPG instead of 15 MPG, it's still pretty bad compared to an electric car that doesn't even burn any gasoline or a plug-in hybrid that might get by without the gas engine for most short trips and still get a very high MPG-equivalent for longer trips (the Chevy Volt has a rating of 95 MPGe, for example).