With the 2012 Infiniti M35h already setting Guinness records and the 2013 Lexus GS 450h shown off at the Frankfurt Auto Show, today's unveiling of the 2013 BMW ActiveHybrid 3 makes it a three-way race for sport-sedan hybrid supremacy. How do the numbers stack up?

Performance

First up, lets look at each car's hybrid drive system. The 2012 Infiniti M35h starts with the familiar 3.5-liter V-6 paired with a 50 kW electric motor for a net output of 360 horsepower. The 2013 Lexus GS 450 follows a similar path, pairing an Atkinson-cycle 3.5-liter V-6 with an electric motor of not-yet-specified output and net power of 338 hp. The 2013 BMW ActiveHybrid 3 slots in just below the other two, but does it a little differently, with a 300-horsepower twin-turbo 3.0-liter inline six-cylinder paired with a 40 kW electric motor for a net output of 335 horsepower.

Lexus says the GS 450h will hit 60 mph in 5.6 seconds, the quickest of the bunch. Infiniti's M35h takes 6.1 seconds, and the BMW 3-Series hybrid hasn't yet made any claims, though the slightly less-powerful non-hybrid 335i makes it to 60 mph in a scant 5.4 seconds--even the 328i, powered by the new N20 turbo four-cylinder, makes the 0-60 run in 5.7 seconds, meaning the GS 450h's hold on the quickest sport hybrid sedan (on paper) is tenuous at best.

Another aspect to performance with this set of modern hybrids is the ability to drive in electric-only mode. While these aren't intended to be driven any substantial distances in electric-only mode, they all offer the ability to some degree. The Infiniti is the speediest, traveling up to 62 mph on electrons alone, but it has a short range of just 1.2 miles. Infiniti says that its test show mixed driving allows the average owner to spend up to 50 percent of the time in electric-only mode, however.

BMW's electric-only mode is not as fast, topping out at 37 mph, but extends the range up to 2.5 miles. It does have the unique ability to coast in electric only-mode at speeds up to 100 mph, however, saving fuel when not on the throttle even at full freeway speeds.

The Lexus GS 450h's hybrid-electric system can drive the rear wheels independently as well as in tandem with the combustion engine, but details on range and speed haven't been announced as yet.

2013 Lexus GS 450h

2013 Lexus GS 450h


Efficiency

Speed isn't the only thing you'll be looking for if you're after a luxury/sport hybrid, however. Saving money at the pump or saving the atmosphere from carbon dioxide and other greenhouse gases will likely be on your mind. Read on to see how these three green powerhouses fare at the pump.

In that metric, it's hard to make an accurate comparison, as BMW has only released European combined cycle figures. Those numbers are typically up to 20 percent higher than EPA combined cycle mpg ratings, so we'll take the claimed 36.7 mpg figure released today with a grain of salt. Lexus' GS 450h hasn't even made a claim to any fuel efficiency figure at all. Only Infiniti's M35h has a solid set of figures from the EPA: 27 mpg city, 32 mpg highway, and 29 mpg combined.

2012 Infiniti M35h

2012 Infiniti M35h

Those are fair and solid numbers for a large-ish, luxurious, and legitimately quick hybrid. We expect the Lexus and BMW offerings to come in around the same figures, though as the Infiniti is the most powerful of the group, it may end up the least efficient by a tiny margin.

The EPA estimates the cost to fill up the tank of the 2012 M35h at $59.67, translating to an annual fuel cost of $1,915 over a typical 15,000-mile year spent mostly in the city. As for CO2 output, the M35h will emit about 6.5 tons per year based on the same criteria as above. That puts it toward the lower end of the market-wide spectrum, but about 2.7 tons of CO2 per year beyond the common hybrid benchmark, the Toyota Prius.

Style

Style, design, and overall aesthetic appeal are inherently personal and individual concerns, but looking at the three contenders as objectively as possible, we don't see a wrong way to go. All three are unique, with the Lexus being perhaps the most modern-looking of the group. The Infiniti's curvy, flowing lines will appeal to some that don't like the edgy bits of the GS 450h's styling. The BMW ActiveHybrid 3 is probably the most conservative choice in terms of exterior styling, but the modern, striking interior trim options may sway buyers that would normally prefer a bit more flash.

Wrap-up

If you're shopping around for a new luxury sport hybrid sedan over the next year or so, all three of these options look to be valid choices. The Infiniti is focused soundly on performance, but at the same time, delivers very good fuel economy for its class. The BMW 3-Series hybrid, on the other hand, hold the potential to outdo the Infiniti in both regards. And the Lexus, while still something of an unknown on the specifics, is positioned to be right in the fight.

Given the early stage of the segment, we're reluctant to name a winner--in the end, it'll come down to personal preference as to which badge you'd rather have in your driveway and how each suits your personal driving style, budget, and needs. The good part is: it doesn't look like you'll go wrong whatever you do.