Which? is calling for more realistic car fuel economy testing after finding 98% of the cars tested couldn’t match or beat their miles per gallon claims.
The cost of fuel is one of the biggest concerns for consumers so the fuel efficiency of new cars has become an important selling point.
It tested 200 new cars across 2013 and 2014 and found that all but three of them fell short of their official mpg figures by 13% on average, resulting in drivers spending £133 more a year on fuel and the worst was the Mitsubishi Outlander PHEV (above).
The official test used by carmakers is outdated and contains a number of loopholes that lead to unrealistic figures. Manufacturers are allowed to reduce results by 4% at the end of the test, can opt to only test in a car’s ‘eco’ mode, turn off lights and air-con, and increase tyre pressures above the recommended levels to reduce rolling resistance. It also doesn’t accurately reflect real-life scenarios, such as motorway driving.
Consumers are being misinformed about their cars’ fuel consumption in advertising and at point of sale, which means they’re likely to end up spending more on fuel. The car that performed worst compared to its official mpg figure was the Mitsubishi Outlander PHEV (a plug-in hybrid), which overstated its mpg by a staggering 120%, costing £459 a year in unexpected fuel costs.
But the car that hit its owners’ pockets the hardest was the Jeep Grand Cherokee – based on Which? tests, drivers will shell out up to £854 a year more on fuel. Other cars that will cost owners a lot more to fuel are the BMW 4 Series Gran Coupé (£421), BMW X4 (£419) and Volvo V60 Plug-In Hybrid (£352).
An improved test, which closely mirrors the one used by Which?, is due to be introduced from 2017, but the European Commission is facing heavy pressure from the car industry to delay this change until 2020 and any further delay will only end up costing consumers. Which? is urging the EC to stand firm and implement the new test in 2017 as planned.
Which? executive director Richard Lloyd, said, “The cost of fuel is one of the biggest concerns for consumers which is why fuel efficiency has become an important selling point for new cars. The new test should be brought in without delay so consumers are no longer misled by fantasy mpg figures.”
For a full table of the 17 worst car models based on driving 10,000 miles per year, see below:
RAC chief engineer David Bizley said: “A change to the standard fuel economy test used by manufacturers is long overdue as the current procedure is clearly not reflective of real world driving.
“As a result many motorists who have bought vehicles expecting high miles-per-gallon figures have been sorely disappointed when they fail to achieve the numbers claimed by the manufacturer.
“This is not good for either the motorist or the manufacturer and therefore needs to be rectified as soon as possible.”
In a statement, Mitsubishi UK said, “To measure a car’s official fuel consumption, the figure which manufacturers use on all technical and marketing material is the New European Drive Cycle (NEDC). This is an independent laboratory test designed to give a level comparison between different vehicles. The official NEDC figure for the Outlander PHEV is 148 mpg.
“However, with average UK daily commuting distances the vehicle can achieve considerably more than this. Longer journeys may reduce this figure but the Outlander PHEV, which is a large 4×4 SUV, will still return impressive economy, such as the 67.3 MPG in the Which? report. Mitsubishi Motors UK has always made this very clear in its advertising and printed material”.
