Both the Chevy Volt (as in Volta, not Bolt as in... bolt) and the BMW i3 with the Range Extender are "series" hybrids: the petrol engine has no mechanical connection to the wheels. It only charges the battery.

In the past six months, we've seen official recognition of this setup as a distinct form of car, "eREV".

Some recent models from China mean that in some markets, you can buy a new series hybrid.

But I'm a series hybrid hipster.