Hybrid car emissions ‘worse than tests suggest’
A NEW generation of plug-in hybrid cars emit up to three times more greenhouse gases in “real world” driving than official figures suggest.
A series of studies found fuel consumption in the plug-in hybrid electric vehicles (PHEVS) was far greater on the road than in official test conditions.
PHEVS have a battery-powered motor and a traditional combustion engine. But they only have a short range in electric mode – typically between 15 and 25 miles – and motorists appear to be neglecting to charge them and instead running them on petrol only.
In a shock announcement on Tuesday, ministers said sales of new hybrid cars would be banned from 2035. Experts said last night that PHEVS could actually emit more CO2 than equivalent petrol-only cars, which are lighter than hybrids because they do not carry the extra weight of a battery and a motor.
A study by The Miles Consultancy (TMC), which conducted an audit of PHEV fuel consumption among fleet drivers, found the more popular PHEVS – BMW, Mitsubishi, Volkswagen and Mercedes – routinely returned fuel consumption figures two-and-a-half to three times higher than official claims.
Correspondingly, cars with official CO2 emissions under 50g/km emitted more than 150g/km under real driving conditions, said experts. The findings were backed up by an academic study in Norway in 2018 on plug-in hybrids, which concluded “the average yearly estimated CO2 emission was 2.5 times higher than the value stated in the type approval official CO2 emission test”. A third series of tests, by Emissions
Analytics, examined fuel consumption on PHEVS when batteries had not been charged and showed alarmingly high fuel consumption.
Company car drivers may be incentivised to fill up with petrol on company credit cards rather than charge cars at home and pay out of their own pocket.
Paul Hollick, TMC’S managing director, said: “There is a real risk drivers are adopting PHEVS for the right reasons but unknowingly increasing their fuel bills. One has to question if some PHEVS ever see a charging cable. In a lot of cases, we see PHEVS never being charged.” One of the most popular hy
brids, the Mitsubishi Outlander, returned 39.1mpg under the Emissions Analytics test when running on an empty battery, compared with an official
fuel consumption, it said was being claimed, of 148.5 mpg. TMC’S audit found the actual fuel economy was 41 mpg. TMC’S audit of other makes
found similar disparities including a Mercedes C Class hybrid that returned 39mpg. TMC said the official fuel economy was 130mpg. TMC recorded an average of 42mpg on 187 BMWS that were being charged regularly that should have returned an average of 137 mpg. Volkswagens returned 52 mpg compared with 163mpg.
Last night, the Government’s own experts questioned the effectiveness of PHEVS, which attracted tax breaks for company car owners. The motor industry estimates sales of PHEVS in Europe this year will go from 220,000 to 590,000. Ewa Kmietowicz, transport team leader at the Committee on Climate Change, said: “There is a concern plug-in hybrids are not being used as intended. By the end of the year most new models of fully electric vehicle will be able to cover 150 miles on a single charge and the need for plug-in hybrids will inevitably decline.”
Nick Molden, head of Emissions Analytics, said: “This is all very confusing for motorists. Official figures are very sensitive to assumptions about how PHEVS are being charged and driven.”
A Mitsubishi spokesman said: “We state in our promotional material that the official figures are only for comparison to similar vehicles and may not reflect real life driving results.”
Mike Hawes, of the Society of Motor Manufacturers and Traders, said: “We can’t comment on non-official tests where the methodology is unclear.”