5.1 Low CO2 technologies
In the last few years, all major car manufacturers have introduced models with substantially improved fuel economy and consequent reductions in CO2 emissions. In some companies these have been branded as an 'eco' variant range (e.g. Ford's ECOnetic, Volkswagen's BlueMotion and Skoda's GreenLine among others). Note that fuel economy and CO2 emissions go hand in hand: since, in petrol and diesel vehicles, CO2 emissions are a function of the fuel used, better fuel economy technologies for petrol and diesel cars also improve CO2 emissions. (The alternative approach of switching cars to fuels with a lower carbon content will be considered in Section 5.2 and later in this free course.)
Key technologies include the following:
- Optimization of the engine for enhanced fuel efficiency
- Auto start/stop – the automatic switching-off of the car's engine when it idles (e.g. waiting in queues or at traffic lights). This can improve fuel consumption by up to 10% in urban driving (see Volkswagen's explanation of for further details).
- Recapturing waste energy through regenerative braking to charge the battery (thus cutting the need for the ICE to generate electric power).
- Tyres with a low rolling resistance.
- Driver information technologies – these include a Shift Indicator Light, to alert drivers to when they can reduce fuel consumption by shifting to a higher gear; and Eco Mode, a driver information system to encourage a more economical driving style.
- Aerodynamics – including body streamlining, radiator grilles, underbody panels and spoilers designed to reduce drag (see pp. 283–4 of Everett et al, 2012, for details).
Cars incorporating these technologies achieve test CO2 emissions for a family hatchback car in the range 80–100 g km−1. As noted previously, actual CO2 emissions and fuel consumption are 20–40% worse than such test figures; as Activity A.5 revealed, a 2050 sustainability target of 20 g km−1 for test CO2 emissions is needed.
Video 1 is a three-minute clip from the motoring programme Fifth Gear that provides an accessible and practical review of this type of car.
If you are reading this course as an ebook, you can access this video here: Fifth Gear Web TV - Ford Focus Econetic Video Diary