Who are you guys?
New nissan note co2 emissions
Emissions scandal: do you own one of the worst performing cars?
New research reveals that many diesel and petrol cars exceed official emissions limits in real-world driving. Is your car one of the worst performers?
R esearch by consumer magazine Which? has found that 95 per cent of cars exceed official emissions limits once they are in the hands of motorists, proving once again that the New European Driving Cycle (NEDC) fuel economy tests are not fit for purpose.
Diesel and NOx (nitrogen oxides) have had their fair share of time in the spotlight recently, following the VW emissions scandal. which revealed that the German company was using so-called "defeat devices " to obtain unrealistically low emissions figures when tested in laboratory conditions. While there's no suggestion that any of the manufacturers named by Which? have used the same technique, their cars were all found to exceed emissions limits when put through its test procedure.
Below we've listed the cars it has so far found to be the worst performing in terms of NOx and CO (carbon monoxide) emissions. The results are taken from Which? laboratory tests, that are said to more accurately reflect real-world driving conditions.
Diesel NOx, the five worst offenders according to Which?
Pumping out 2.7g/km of NOx, the Jeep Grand Cherokee, 3.0-litre diesel emitted 15 times the permitted Euro 5 limit of 0.18g/km, making it by far the worst performer in the Which? tests.
The Jeep Grand Cherokee did not perform well in the Which? tests
The Forester is a niche choice in the UK, but has a reputation for being tougher than old boots. Unfortunately, while the 2.0-litre, flat-four diesel model passed Euro 5 emissions tests, it produced far more NOx in the hands of Which. at 1.19g/km
Despite its 1.6-litre diesel engine officially adhering to Euro 6 NOx limits, which should in theory make the Nissan X-Trail one of the cleanest diesels on sale, in the Which? tests it produced 1.05g/km of NOx, or 13 times the 0.08g/km limit.
Another Nissan, and a very popular one at that, the Qashqai 1.6-litre diesel produced 0.99g/km of NOx when tested by Which. despite officially complying with Euro 5 emissions legislation of 0.18g/km.
Yet another SUV that failed to make the grade was the Kia Sportage, with a 2.0-litre diesel engine that emitted 0.93g/km of NOx.
Petrol NOx, the five worst offenders according to Which?
While cleaner than diesel models in terms of NOx emissions, in the Which? tests 10 per cent of petrol cars still produced more of the harmful gases than permitted in the Euro 5 and Euro 6 tests, where the limit is set at 0.06g/km.
The SL's 3.5-litre engine produced 0.2g/km of NOx in the Which? test, which is said to be more representative of real-world driving than the NEDC cycle. It was the worst performing petrol car by some margin.
According to Which. the petrol-powered Mercedes SL was found to emit more NOx emissions than allowed in official tests
The 2.0-litre petrol engine in the E-class officially passes Euro 6 emissions tests, but according to Which? emits almost three times the permitted amount of NOx, at 0.17g/km.
The Mini's 1.5-litre, three-cylinder engine is a delight to drive and usefully economical, but Which? found that it pumped out 0.16g/km of NOx in real-world conditions, which is well above that 0.06g/km permitted in Euro 6 tests (which the Mini passed).
Nissan has not come out well in the Which? tests, with the X-Trail, Qashqai and now the Pulsar hatchback all failing to replicate the figures obtained in the NEDC test procedure. In the case of the Pulsar, its 1.2-litre petrol engine emitted 0.15g/km of NOx.
It's another poor result for the hugely popular Qashqai, which when fitted with the same 1.2-litre engine as the Pulsar emitted 0.12g/km, making it the fifth highest creator of NOx of all the petrol cars Which? has so far tested.
Petrol CO, the five worst offenders according to Which?
Carbon monoxide is a potentially harmful gas emitted by car engines, and while it's no surprise to find that cars emitted more of it in real-world tests than they do in the NEDC cycle, just how much more might come as a shock. Here are the worst five offenders, according to Which?
Not many people bought a Veloster, with its odd door arrangement and unconventional styling, which is probably a good thing given that the 1.6-litre petrol engine was found to emit 6.11g/km of CO, or six times the 1g/km limit.
The Hyundai Veloster performed poorly for CO emissions in the Which? tests
The Nissan Note might be a small car, but in the Which? tests it produced well over the Euro 5 CO limit of 1g/km, at 5.36g/km.
If you bought a tiny, fuel-sipping Toyota Aygo because you wanted to minimise your environmental impact, than you might be alarmed to hear that it produced 4.91g/km of CO when tested by Which. or almost five times the NEDC limit
Proving once again the inadequacies of official fuel tests, the Alfa Giulietta - which is certified as Euro 5 compliant - emits well in excess of the permitted limit in a more realistic driving cycle, at 4.69g/km.
The 370Z, with its 3.7-litre V6 engine is exactly the kind of car that you know will struggle to match its claimed fuel economy figures in real world driving. According to Which. the same is true of CO emissions, with 4.63g/km produced at the exhaust in its test.
The data from Which? does not indicate that other manufacturers have been fitting defeat devices to their cars, and there is no such insinuation in the reporting of its findings.
Rather, it's yet more proof that the official emissions tests new cars are subjected to bear very little resemblance to how motorists use their cars, which is why so few are able to get close to official economy figures. As such, Which? has released the data to encourage people to sign up to its Come Clean on Fuel Claims campaign.
The New European Driving Cycle (NEDC) is the “official” economy test that all new cars have to conform to, and the figures obtained are the only ones that manufacturers are allowed to quote. But just what is it about this test that produces such wildly optimistic claims?
Figures are quoted as Urban, Extra-Urban and Combined. For Urban economy, the car is placed on a rolling road and made to accelerate and decelerate several times, as well as holding a steady speed and sitting at idle. Maximum speed is 31mph, the average 9mph.
Car emissions are measured in a laboratory Credit: Patrick Pleul/EPA
T he Extra-Urban result is made up of 50 per cent driving at a steady speed, plus a similar mix of accelerating, slowing down and letting the engine idle. Top speed is 75mph and the average 39mph.
The Combined figure is literally an average of the previous two, weighted by the distance covered.
In theory this all sounds reasonable enough. However, unlike when you or I drive, the tests are conducted in a laboratory on a flat rolling road – so there are no head-, side- or tailwinds (although the test does simulate aerodynamic drag) or hills to worry about, nor the kind of temperature fluctuations that real motorists have to deal with (the lab is always between 20-30C).
In addition, all electrical features which would increase fuel consumption (and therefore certain emissions) are switched off, including the lights, heater, radio and air-conditioning. The real problem, however, is that the acceleration in the test occurs at a snail’s pace. To move from rest to 9mph takes 4sec; to 20mph, 12sec; and to 31 mph, 26sec. Try that next time you’re in the car and see how it feels.
Furthermore, the tests are carried out over tiny distances; just 2.5 miles for the Urban figure and 4.3 miles for Extra-Urban. It’s no surprise the figures obtained, whether it's fuel economy or NOx and CO output, are so difficult to achieve when the test itself is completely unrepresentative of how people drive in the real world.
For all the latest news, advice and reviews from Telegraph Cars, sign up to our weekly newsletter by entering your email here