The BMW i3 used what was basically a scooter engine. The Ampera/Volt used what was essentially an Opel Corsa engine (from memory).
Toyota's approach of using a small battery and modified atkinson cycle engine seems to have paid off. Taxi drivers love them and fuel economy is pretty consistent. But the engine is a core part of the process. So it isn't dead weight a lot of the time.
The real question is whether an 'Extended Range EV' is using a motor intended to work efficiently as just a generator or whether it's another parts bin special.
The BMW i3 used what was basically a scooter engine. The Ampera/Volt used what was essentially an Opel Corsa engine (from memory).
Toyota's approach of using a small battery and modified atkinson cycle engine seems to have paid off. Taxi drivers love them and fuel economy is pretty consistent. But the engine is a core part of the process. So it isn't dead weight a lot of the time.
The real question is whether an 'Extended Range EV' is using a motor intended to work efficiently as just a generator or whether it's another parts bin special.