Increasing the amount of bioethanol in petrol harms fuel efficiency and may actually result in higher CO2 emissions from cars, warns What Car?
The automotive magazine is calling on the government and the automotive sector to do more research into the impact of higher bioethanol mixes in petrol, after its tests suggested that they increased fuel consumption and CO2 emissions.
Under EU rules aimed at ensuring that 10% of the bloc’s transport fuel is from renewable sources by 2020, petrol in the UK currently contains up to 5% bioethanol (E5). Last year, standards were introduced to enable suppliers to increase that mix to 10% (E10).
What Car? tested four road cars – a three-cylinder turbo (Dacia Sandero), a naturally aspirated car (Hyundai i30), a hybrid (Toyota Prius+) and a four-cylinder turbo (Mini Paceman) – comparing their fuel efficiency and the amount of carbon emissions generated running on E10 and pure petrol.
The researchers found that fuel consumption increased by 8.4% on average, while CO2 tailpipe emissions increased by 3.9% or 6.4gCO2/km. The 0.9 litre Sandero was most affected by the increase in the amount of ethanol in the petrol, with its fuel economy falling 11.5% (3.9 miles per gallon) and its carbon emissions increasing 7.3%. The turbo-powered Mini, meanwhile, was the least affected, with CO2 rising just 1%.
“We weren’t surprised to find that all of our test cars used more petrol when driven on E10, but what did shock us was just how much more fuel they got through on E10 over ethanol free petrol,” commented Emma Butcher, consumer editor at What Car?.
“Our tests clearly show that adding ethanol to your tank can have a much bigger impact on fuel economy than experts have predicted. We are now calling for more intensive real world research to take place on a much wider scale before E10 is pushed out to our petrol pumps.”
The research findings came as the European commission agreed to amend Regulation 510/2011, which sets mandatory limits on the amount of carbon emissions new vans can produce.
Under the amending regulation, manufacturers of light commercial vehicles must still ensure that their vans produce less than 147g CO2/km on average by 2020, however, it amends the methods for reaching the carbon reduction target.
The new regulation will apply to manufacturers producing more than 1,000 new light commercial vehicles registered in the EU each year and allows firms to use innovative technologies to achieve the necessary CO2 savings up to a maximum of 7gCO2/km.
The EU has a bloc-wide target of 175gCO2/km phased in up to 2016, and each manufacturer has a target based on the weight of each new van it registers in a given year. In 2012, more than 239,000 new vans were registered in the UK alone.
