The next-gen BMW 5-Series sedan has been spied yet again and it had two fuel caps indicating it was a plug-in hybrid variant.

The next-gen BMW 5-Series sedan has been spied yet again and it had two fuel caps indicating it was a plug-in hybrid variant.

The fully camouflaged prototype had an extra fuel cap on the front left fender for charging the lithium-ion battery pack part of the hybrid system that will likely be derived from the recently unveiled 3-Series plug-in hybrid prototype. That one has a four-cylinder 2.0-liter turbocharged gasoline engine mixed up with an electric motor and a lithium-ion battery providing a combined output of 245 HP & 400 Nm but expect these figures to grow for the larger and heavier 5-Series (G30).

In terms of styling, the new 5-Series will be influenced by BMW's flagship 7-Series model set to come out next year. Both of them will be riding on the new "35up" platform and in the case of the 5 this should enable a 100 kg (220 lbs) weight loss.

The conventional-powered next-gen BMW 5-Series sedan is believed to go on sale in July 2016 and chances are the plug-in hybrid derivative won't be available from day one so it will probably be launched early 2017.

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