Labelling the Point

Feature

LowCVP’s managing director, Andy Eastlake, explains the new Car Fuel Economy Label and how it can help fleet buyers make an informed choice

The Car Fuel Economy Label will hopefully be familiar to everyone reading. Introduced in 2005 by the LowCVP, it provides colour-coded comparative information on CO2 emissions, fuel consumption and annual fuel costs and road tax for all new and used cars. All of this information can help both fleet managers, as well as the general public, calculate the typical costs of running their vehicles.

With the new range of electric and plug-in vehicles on the market and changes to government regulations, the existing label needed to be updated in order to accommodate these new technologies. So earlier this year LowCVP members, including the DfT and stakeholders from the automotive industry, developed new versions of the fuel economy label to incorporate the plug-in vehicles now widely available such as Vauxhall’s Ampera, Nissan’s Leaf, and Toyota’s Plug-in Prius amongst others.

Reflecting different technologies
The challenge was to continue to provide a robust fuel consumption comparison, but also to reflect the very different nature of the technologies adopted. Having experienced all three of these vehicles at first hand, I can vouch for the fact that you need to live with them in order to understand how they work and how they best fit into your own personal driving patterns.

The objective of the label is to give the users information in a simple, friendly and accessible way that will assist their decision making in the car buying process and avoid confusion.

Of course the starting point for all the labels is the standard fuel economy test (or NEDC [New European Driving Cycle] as it is commonly known). The cycle is universal and every car type (and van), are tested over the same 11km. In the case of a conventional vehicle or regular hybrid, running this one test starting from a standard overnight parking at (an albeit rather balmy!) 25 deg C, measures the fuel economy over the city (or urban) phase (the first 4km) and the motorway (or extra urban) drive with the overall consumption calculated across the whole test.

Pure Electric
When we now look at an electric vehicle such as the Leaf, it is fairly easy to see how the same approach can be used with the vehicle charged overnight to full battery and driven over the same cycle. We then reconnect the charger and measure how much electricity is used from the grid to charge it back up (so the measure includes the charger efficiency). This gives us the electricity used per mile.

Of course a critical aspect of any electrical vehicle is the range. And for this we do not rely on just calculation from the battery size. The vehicle is actually charged again and driven
over the same cycle repeatedly
until it won’t go any further.

For the annual electricity cost shown on plug-in hybrid and electric vehicle labels a standard price for electricity based on an average from government figures is used (in a similar way as the petrol and diesel prices are defined). Of course I would challenge any of you to find diesel priced at half the pump price overnight, whereas of course the savvy EV driver can get his electricity substantially cheaper than the price used for the label through intelligent choice of charging.

Plug-in and EREVS
When we looked at the Plug-in and EREV (Extended Range Electric) vehicles, the whole structure of the label became much more complex and exercised the team significantly. We tried to focus on the key bits of information that would highlight what questions to ask and how to think about these vehicles when making a purchase decision.

What is the range on electricity and how many miles can I travel on one unit of electricity or liquid fuel on a typical journey?

One of the constraints was that we could only draw on data from the standard test procedure, which prescribes how these vehicles are measured for certification. Whilst this gives a direct comparison with conventional vehicles, it makes a key assumption about what the standard journey for a plug-in vehicle will be. It is assumed that a typical driver will start his/her vehicle with a full charge and will drive until the battery is empty and continue on for 25km (15miles) before charging again. It is this journey that gives us the ‘weighted combined’ figures used on the label. If that describes your behaviour and you drive to the NEDC profile, you will get 235mpg from your Ampera and use 4.8KWhr per mile. However, if your driving or journey profile is different your consumption will also differ and with many plug-ins it can be possible to run exclusively on electric power to avoid any liquid fuel use at all.

But even the Ampera, as a range-extended EV, is relatively simple to label in comparison to the Plug-in Prius. As the Prius is a true hybrid, the engine will start and support the drive at speeds around 50mph or under harder acceleration, meaning that over a standard test cycle the engine will come on even when the battery is not depleted. So the electric range result reflects the range of electric driving but does not include portions of the cycle when the engine has switched on. Whereas the consumption data used on the label gives the results when driving the standard cycle using both petrol and electricity.

Irrespective of your views on fuel economy in the real world against the test cycle, giving the official CO2 and fuel economy numbers for comparison between vehicles is key to helping make the right choice, as the rates for both Vehicle Excise Duty and Company Car Tax are determined from these results.

Consumer information
In considering the new labels we carried out some initial research into what consumers like and understand in terms of the information provided. The results of this revealed some interesting insight into consumers perceptions and will be used to help us decide how the label should develop, but for now it was important to incorporate the latest technology into the labelling requirement with as little change to the layout as possible.
The new label gives the purchaser directly comparable information from a certified test and, with any luck, will allow them to have an informed discussion with the vehicle salesman about how to choose the right technology. As our vehicle choices expand it is impossible to predict what technology challenges we might be faced with in the future, but rest assured the LowCVP and its members aim to keep carbon and energy efficiency data foremost in the presentation of vehicle information.