The Ford Fiesta is the UK’s best-selling car. It has been every year for the best part of a decade. But tests conducted by the UK Government has uncovered that a petrol variant produces more harmful emissions on the road than drivers have been led to believe.
The Driver and Vehicle Standards Agency (DVSA) on Thursday published the latest results of emissions tests conducted on the most popular petrol-powered cars used on UK roads.
And while it said that the vehicles tested were ‘generally compliant’ with the emissions levels during official measurements, some – including the Fiesta – showed ‘poor real world emissions’ when driven under normal conditions.
The study also uncovered that a petrol Nissan Qashqai – the UK’s most-bought SUV – exceeding the EU’s pollution guidance limits when used on the road.
Petrol isn’t as clean as we think: New DVSA tests found that petrol-powered cars are producing significantly more NOx emissions on the road than during legislative tests, including the previous-generation Ford Fiesta (pictured)
The test of petrol models follows a similar study conducted by the Department of Transport in April 2016 in response to the Dieselgate scandal revealed just months before.
While the testing did not find evidence that other manufacturers were using equivalent ‘defeat devices’ found in VW models, the DVSA identified higher levels of nitrogen oxide (NOx) emissions during real world driving conditions than those produced during legislative laboratory tests.
NOx emissions – which are strongly linked to diesel cars – have been blamed for 5,000 premature deaths across Europe each year, with the Royal Colleges of Physicians and of Paediatrics and Child Health claiming that 40,000 people are killed early by poor air pollution levels in Britain annually.
However, this latest study suggests unleaded-powered passenger vehicles are doing plenty of damage too.
The research mirrored the 2016 diesels test but solely looked at the emissions impact of petrol cars and vans as well as popular trucks and buses.
Carried out last year, tests were conducted to the previous NEDC standards used for type-approval of new vehicles, which was replaced by the Worldwide harmonized Light vehicles Test Procedure (WLTP) from September last year.
DVSA scrutinised 15 popular petrol cars in total that used both direct and indirect injection engines.
When measured using the legislative laboratory test, all models complied with the regulatory limits, the government agency said.
However, NOx outputs for some cars were much higher when emissions were metered while the vehicles were being driven on the road, which it said would ultimately contribute to poor air quality.
The DVSA reproduced legislative lab tests on each of the 15 petrol cars and found that all were well below the NOx emissions limit
However, when measurements were taken on the road, the Qashqai breached the EU’s higher recommended emissions guidance limit and the Ford Fiesta crept close to the allowance given when driven in real world conditions
Nissan Qashqai over EU recommended guidance limit on the road
The Sunderland-built Nissan Qashqai was identified as the worst performer of the cars reviewed.
On the road NOx emissions measurements were almost ten times higher than the average for the 15 petrol cars tested by the DVSA and over the 300mg/km NOx limited stated by the EU.
It was also higher than some diesel cars it tested a year earlier.
Nissan confirmed that it had achieved similar results during its own tests and suggested it was because the engine was smaller – downsized in an effort to emit less carbon dioxide – and therefore being worked harder than bigger motors when driven on the road.
DVSA requested that Nissan develop a recalibration for the vehicles to improve the real world NOx performance, however, the Japanese car maker stated that it was still considering whether that was possible.
In the meantime, Nissan confirmed that a new engine will directly replace this particular variant of the Qashqai in the summer.
The DVSA said the NOx emissions of the petrol-powered Nissan Qashqai it tested was higher than some diesel models it measured in 2016
The stats from the DVSA’s 2016 study showed that 8 of the 19 diesels it tested were above the emissions allowance when tested on the road
Ford blames higher emissions on cold weather
It was a similar story for the UK’s most purchased new and used car, the Fiesta.
NOx emissions in the laboratory were on average 18mg/km – well below the legislative test limit of 60mg/km.
HOW DID DVSA TEST VEHICLES?
Tests were conducted by the DVSA’s Market Surveillance Unit (MSU).
It measured the emissions during Real Driving Emissions (RDE) conditions – a standard that will be introduced for all manufacturers to undertake from September 2018 to ensure that their vehicles don’t exceed pollution limits during normal driving conditions.
The cars and vans checked were chosen based on the most popular models by sales figures, while two- and three-axle rigid-bodied trucks and buses were selected for tests.
Measurements for cars and vans were taken in lab and track conditions at the Vehicle Certification Agency’s grounds in Nuneaton.
On the road measurements were taken while driving around the surrounding area, with each model driven for one and a half hours to take readings from exhaust pipes.
Trucks and buses were tested for two and a half hours in order to take conclusive measurements.
However, measurements taken on the road were significantly higher, at a 264mg/km during real world driving conditions, close to the 300mg/km guidance limit given by the EU.
‘This is a surprising increase in NOx emission and is not in alignment with that seen from other petrol cars in the programme,’ DVSA said in their report.
Ford blamed the cooler test temperatures (0 to 1 degrees Celsius) during the DVSA’s study, which it said would increase both aerodynamic drag and rolling resistance.
The car maker argued that the ‘combination of conditions are outside the normal Fiesta customer usage profile’ and said it would not be possible to conduct any service actions to make the engine run cleaner.
It also said that the variant tested has since been replaced by a new version.
Ian Bartlett, Head of the Market Surveillance Unit at the government agency, said: ‘The results of the tests demonstrate the importance of the new ‘real driving emissions’ legislation and the much stricter laboratory tests introduced in 2017.
‘We look forward to seeing industry bring forward cleaner vehicles with more representative fuel economy figures.
‘Our tests show that some will have to make substantial improvements to meet the new rules.’
Ford argued that the Fiesta model tested (similar to the one pictured) has since been replaced by a new version. It said it would not be able to take action to improve the emissions output of the vehicle
An older Euro 5 Jeep Grand Cherokee tested was found to have breached NOx emissions limits during the study, but the manufacturer has agreed to voluntarily update their vehicles to improve this.
The study also identified one non-compliance in the heavy duty sector – an Iveco truck.
The manufacturer has since agreed to recall its vehicles voluntarily so that it can recalibrate the software to correct the issue.
The DVSA added: ‘We remain concerned by the poor real world emissions control of a number of the other vehicles we tested this year .
‘While these appear to comply with type approval requirements, as with the Euro 5 and Euro 6 diesel cars that we tested last year , their real world NOx emissions are much higher and are directly contributing to the air quality problems we face and the resulting health impacts.
‘We therefore intend to conduct a further programme of emissions testing across all categories over the next year.’
In addition to emissions, the MSU’s testing also looked at fuel economy figures.
In most cases the real world miles per gallon figures achieved were worse than official test figures. And in some cases the MSU was unable to replicate the manufacturers’ claims even under the same lab test conditions.
Mike Hawes, chief executive at the Society of Motor Manufacturers and Traders, said: ‘Government testing has shown all cars tested to be compliant with legal requirements.
‘The differences between the results from official laboratory emissions tests and those performed in the ‘real world’ are well known, and industry supports September’s introduction of the new and more onerous on-road test, RDE, which will help to reflect better ‘real world’ driving.
‘This is requiring significant additional investment by manufacturers but will add greater transparency so consumers can be confident they are buying the cleanest and safest cars in history.’
Earlier this week the DVSA warned drivers of diesel cars that their vehicles face tougher scrutiny as part of new MOT checks.
This includes an inspection of the emissions system of models with diesel particulate filters in a bid to improve air pollution.
If the exhaust pipe shows any signs of smoke production, cars will automatically fail the test.
SAVE MONEY ON MOTORING