One of the biggest challenges – and cause of much frustration – for many drivers is to try and match the real-world fuel consumption performance of their new car with the official figures used in the sales literature.
Research (see: ICCT, EU) has shown that the discrepancy between the published data and the on-the-road reality is even higher for the latest generation of low- and ultra-low carbon cars.
Partly the gulf between expectation and actual experience is down to the habits of the person behind the wheel. Driving style is central to the amount of fuel we consume. Behaviour like over-revving, idling at traffic lights, and sharp acceleration and deceleration can all contribute to wasting petrol and diesel.
However, the discrepancy is also due to the fundamental difference between the standard, pre-determined test cycle (in the case of the UK, the new European drive cycle, or NEDC) and the myriad journeys we make ‘in the wild’ none of which are likely to met the strict criteria of the laboratory. Unsurprisingly, automotive engineers design vehicles precisely to suit these official trials, but it is equally unsurprising that most motorists have to fill up at the pumps more often than they might have been expected to believe.
All of which makes work being done at the University of Toronto of potential interest to those people buying the two million new cars sold in this country annually. At the Transport Research Board Annual Meeting in Washington DC last week, Canadian researchers described how they have created a computer microsimulation which allows the generic test data to be adjusted in light of the real journeys we all make.
Their work offers up the possibility of vehicle buyers being able to walk into a showroom and tailor the official figures to the type(s) of journey they make most often be it motorway, urban or rural. Suddenly the NEDC figures aren’t just abstract numbers which have little in common with everyday driving experience but instead they are the basis for carefully crafted individual calculations which are unique to the lives we each lead and the specific trips we take and much more meaningful because of it.
RAC Foundation Blog 