Two days, two range-extenders. Last Friday, I travelled to Ballymena in Northern Ireland to see the first production example of the new London bus (powered by a 4.5-litre diesel engine/generator and 17kWh battery) and then immediately hot-footed it (via taxi, plane, Nissan Leaf, feet, train and feet) to Brighton to drive the Chevrolet Volt (1.4-litre petrol engine/generator and 16kWh battery) in the Future Car Challenge.

It’s a year since I drove the first Chevy Volt at the launch in Michigan and my view of the car hasn’t changed. It still looks and feels like the future, even if this first-generation powertrain is not without its conceptual flaws.

The Brighton to London run in the Volt was a game of two halves: the 65.8 mile drive was conducted almost exactly 50:50 between the battery and the petrol-powered engine/generator.

The battery pack was actually charged up last Monday, before the Volt left GM’s care in Germany, so when we fired it up before 06:00 on Saturday morning there was a suspicion it wasn’t operating from the full 100 per cent.