Call the 2012 BMW 5 Series GT what you want, but it's not a slow vehicle. BMW's been fiddling with the 2013 model, and now promises both more horsepower and better fuel economy for the high-riding tourer.
The tweaks, which first debuted on the 2013 BMW 5 Series GT in England, will also come to the American models for the 2013 model year. For starters, the 5 Series GT will now come with automatic engine stop-start, as well as the same selectable Eco Pro driving mode as the 2012 BMW 3 Series sedan. That mode, which tunes throttle inputs and other energy-saving settings to maximize fuel economy, is the main culprit behind why BMW says all 5 Series GT models will get a modest boost in the mpg ratings. BMW claims the 535i GT will increase by 2.25 mpg and the 550i GT will increase by 4.6 mpg.
While the 535i GT soldiers on with the same 300 hp and 300 lb-ft of torque as always, engineers managed to boost the 550i GT's power by at least 10 percent. The 2013 550i GT, which is powered by a 4.4-liter twin-turbocharged V-8, will jump 45 hp and 30 lb-ft in power output, which now stands at 445 hp and 480 lb-ft.
It appears that BMW was able to do this by (sort of) switching engines: while 2010-2012 550i GTs were powered by BMW's N63 engine, the 2013 and onward models will use the N63Tu (Tu standing for high performance) powerplant that also goes under the hood of the 2013 650i Gran Coupe.
It's unclear at this point whether or not the newly tweaked V-8 will go into the new 5 Series sedan -- a BMW representative we reached this morning couldn't confirm or deny the move -- but it seems rather likely.