It goes without saying that cars are expected to match the performance estimates their manufacturers quote, but it's always nice when one exceeds them.

It turns out that the 2015 Mercedes-Benz S500 Plug-In Hybrid is a little quicker and a little more efficient than Mercedes originally said. The German carmaker released revised performance specifications that trump those released ahead of the car's debut at the 2013 Frankfurt Auto Show.

While Mercedes originally pegged the S500 Plug-In Hybrid's fuel economy at around 78 mpg, it now claims the car will return 84 mpg. Both figures are based on the more-optimistic European testing cycle; EPA fuel-economy numbers will have to wait until closer to the car's launch.

In addition, the S500 Plug-In Hybrid's electric-only range has increased from around 18 miles to just over 20 miles, and the 0-62 mph acceleration time has dropped from 5.5 seconds to 5.2 seconds. The governed top speed appears unchanged at 155 mph.

The S500 Plug-In Hybrid is powered by a 3.0-liter turbocharged V-6 paired with an electric motor and trunk-mounted lithium-ion battery pack. The gasoline engine produces 328 horsepower and 354 pound-feet of torque, while the electric motor kicks in an additional 107 horsepower and 250 pound-feet of torque.

As with other parallel hybrids, the S500 features multiple driving modes that use different combinations of gasoline and electricity, including "E-MODE" (electric only), "HYBRID" (a mix of both), "E-SAVE," (reserves the fully-charged battery for later use), and "CHARGE" (charges the battery while driving).

The S500 Plug-In Hybrid is expected to go on sale next spring. Pricing won't be announced until then, but it will likely fall somewhere between the $96,825 S550 and the $140,425 S63 AMG.


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