Do hybrid cars really offer better fuel economy?

There’s lots of talk about hybrid cars , but do they really offer better fuel economy and lower emissions than a conventional petrol or diesel car?

As an example, let’s take a car in one of the UK’s best-selling segments, the supermini class.

A hybrid car in this class is the Honda Jazz 1.3 IMA which returns a combined fuel economy figure of 62.8mpg, along with emissions of 104g/km CO2. This is the sort of miles per gallon that you’d expect from a diesel-powered car. However diesel cars produce a range of emissions that have a negative impact upon local air quality, and in 2012 a panel of experts working for the World Health Organisation said that exhaust fumes from diesel engines cause cancer.

The Honda Jazz has a 1.3-litre petrol engine and additionally a small battery and electric motor. Under normal operation the petrol engine of the Jazz has cleaner emissions than a diesel engine, and at standstill the Jazz doesn’t produce any harmful tailpipe emissions, because the petrol engine shuts down, and the electric motor cuts in.

The electric motor also ‘assists’ the petrol engine when needed, such as under acceleration (Honda calls its hybrid system ‘IMA’ which stands for ‘Integrated Motor Assist’). The Jazz hybrid doesn’t need to be plugged in to an electricity supply to charge the battery, instead it recharges itself when braking – the energy that would otherwise be lost when braking is captured and put back into the battery, to enable this energy to be used to help power the car again.

So the hybrid system effectively recycles energy that would otherwise be lost, meaning that the Jazz is more efficient than the average supermini.

There is a big debate at the moment about real-life miles per gallon compared to official miles per gallon. Can the Honda hybrid system deliver the economy that is claimed? Over the last three years one of Green-Car-Guide’s contributors has owned a Honda hybrid and he accurately recorded the miles per gallon based on actual fuel used. Over three years he achieved within 1mpg of the official claimed combined miles per gallon figure, showing that if hybrids are driven carefully they can deliver real cost savings on fuel in real life.

Another Honda hybrid won the hybrid class in the 2011 RAC Future Car Challenge, using just 29.8 kWh of energy consumption over the 60-mile Brighton to London route, equating to over 90mpg.

There are also other hybrid cars from Honda UK: the CR-Z sports coupe and the Insight family hatchback. But perhaps the most exciting of all is the forthcoming new NSX supercar, which will also be a hybrid, but in this case mated to a mid-mounted V6 petrol engine.

For all news and updates, including detailed specifications of all Honda Hybrid cars , you can consult the hybrid section on their website.