Whether you call it "premium," "super unleaded," or even "high test," it all means the same thing -- the most expensive gasoline at the pump. In a somewhat counterproductive trend, the skyrocketing cost of fuel is forcing automobile manufacturers to use smaller and more powerful engines, often with forced-induction. Unfortunately, these engines require higher octane... the distinguishing feature of premium fuel.
Kelley Blue Book has been following the trend and according to their analysis, there were 166 vehicle models that required premium fuel in 2002. This year, that number is up to 282. While some automakers only require premium for their highest performing models, companies like BMW call for premium fuel across their model range.
While there is no advantage to running premium fuel in an engine that doesn't call for it, you should run the higher octane fuel in a powerplant designed for it (if in doubt, check the owner's manual, or the inside of the fuel filler door). While nearly every late-model high-performance engine on the road can handle a slightly lower octane rating without damage, don't skimp when filling up as your fuel economy and horsepower will suffer (yes, it will likely negate any savings at the pump).
[Source: USA Today]