Honda keeps it simple with the Insight: just one powertrain is offered. It is known as Integrated Motor Assist (IMA) and comprises an 87bhp 1.3-litre petrol engine assisted by a 14bhp electric motor.
As hybrid systems go, IMA is one of the more simplistic, with a permanent connection between the petrol motor and transmission. If the wheels are turning, so is the engine. Whether it is using any fuel is a different matter.
Although the Insight will not move off from standstill on electric power alone, once moving it can run on just electric power. But because it still has to turn the engine, it is less efficient than the more complex system found in the Prius, which allows the engine to disconnect completely. Drive is channelled to the front wheels through a CVT transmission.
In the real world, though, the manner in which the Insight delivers its performance is less satisfactory. On anything but light throttle applications, the engine is pretty vocal, and not in a pleasant way. The problem is exacerbated by the CVT transmission, which under full throttle keeps the engine spinning at constant high revs. It requires a committed approach to get the sort of performance suggested by the headline numbers, and especially to pick up speed on the motorway; effortless it is not.
In less pressing driving, the Insight is a quieter companion, but still the transmission isn’t the smoothest. The action of the petrol motor cutting in and out is more noticeable than in the Prius. Switching to Econ mode, which reduces power slightly and smooths out the throttle map and CVT operation, improves matters marginally.