THE Hyundai Nexo is a car with a difference - in more ways than one.
Not only is it fuelled by hydrogen, drives on electricity and produces no CO2 emissions, it also has a special filter fitted that actually cleans the air as it drives along.
And for the past few weeks a right-hand drive, British registered Nexo has been driving some of London's most polluted roads to do its bit during Clean Air Month.
We joined in and took the Nexo on a drive from Park Lane, around Marble Arch and then along Marylebone Road to Kings Cross and back.
That is one of the most polluted routes in the capital where the EU limits for particulate matter and nitrogen dioxide can be exceeded.
It's just under seven miles long but in London traffic it took more than half-an-hour to cover and according to the Nexo's onboard readout we managed to purify the equivalent of more than eight kilos of air and reduce CO2 output by 1.5kg.
According to Hyundai, the Nexo can purify 26.9kg of air for every hour it's on the road - and that's the equivalent of what 42 adults breathe in the same time.
The filter is fitted to the Nexo as part of its hydrogen fuel cell powertrain which requires clean air to function efficiently and under regular conditions will be changed at service time.
For the clean air exercise Hyundai teamed up with University College London which had mapped out a ‘most polluted route' using data from a King's College London study which analysed nitrogen dioxide (NO2) and particulate matter (PM) levels in the capital.
The Nexo's filter absorbs 99.9 per cent of fine dust known as PM2.5 - that's particulate matter that is impossible to see and less than 2.5 micrometers in diameter, about three per cent of the diameter of a human hair.
When absorbed by humans such particles can cause respiratory and vascular problems and levels are considered unhealthy when they rise above 35.4 Î¼g per cubic meter in a 24 hour period.
On our route, levels in Park Lane, around Marble Arch and in Marylebone Road regularly come close to that.
The effect of the Nexo on the environment can be shown on the car's central display screen which revealed we had purified 7.2kL of air - or 8.82kg - enough clean air for five adults.
Sylvie Childs, Hyundai's senior product manager for the Nexo said: "We are all concerned about air quality and what affects it.
"At Hyundai, we are committed to improving the efficiency and environmental performance of all our vehicles and have been investing billions in bringing a full range of low and zero emission vehicles to the market place.
"We believe that the availability of alternatives, like the Nexo fuel cell electric vehicle, will bring the UK closer to its zero emissions future."
The Nexo is powered by a fuel cell which generates electricity from hydrogen and it is emission free, the only waste product is water.
With a range of 414 miles from three 11.5 gallon fuel tanks the Nexo can be refuelled in around five minutes, little different to a regular visit to a filling station and much quicker than the 45 minutes it takes to quick-charge the latest generation of battery/electric vehicles for fewer miles.
At the moment, a full refill for a Nexo will cost in the region of Â£80 - about the same as many a large car.
From a technical point of view, the Nexo is in the same league as any other five seat family car - it's similar in size to a Nissan Qashqai - and has a 0 to 60 time of 9.2 seconds, a maximum of 111mph and the power output is equivalent to 163ps.
The instrumentation is high tech with a central 12.3-inch touchscreen in the middle of the dash sitting above an array of controls in the centre console for the ventilation and entertainment systems.
Gear selection is push button - there's only drive, reverse and neutral - and there is a handy, auto-hold function for the electronic parking brake which is a boon in traffic.
Another useful feature is a readout which converts hydrogen consumption into the equivalent miles per gallon and on our run in rush-hour London the Nexo averaged 61.8mpg - impressive given the traffic conditons.
The Nexo comes with a full set of safety features including a semi-autonomous lane following assist function which automatically adjust steering to keep the car in the centre of its lane.
With SUV-like looks room inside is above average and luggage space ranges from 461 litres to a maximum of 1,466 with the rear seats down.
The Nexo is Hyundai's successor to the iX35 fuel cell vehicle and will be on sale in 2019.
The downside is the price - expected to be in the region of Â£60,000 - and the current lack of infrastructure for hydrogen powered vehicles.
At the moment there are just 11 filling stations in the UK sited in four clusters around London, Swindon, Sheffield and in Aberdeen.
Plans are in place to increase that to 55 stations by 2030 but the technology is still very much in its infancy and Hyundai is backing moves for the government to incentivise take up of fuel cell and other low emission vehicles.
Dr Michael Whiteley, head of fuel cell engineering at UCL's Electrochemical Innovation Lab said: "The recent report from the Intergovernmental Panel on Climate Change (IPCC) indicates that much more needs to be done to mitigate negative climate change.
"Our research into fuel cell technology has found it to be a promising transport solution to consider as an alternative to fossil fuel dependent cars and battery electric vehicles which have long charging times.
"Our research stretches from fundamental material science to full automotive fuel cell power systems for automotive applications. Going forward, we're building an advanced propulsion facility where we will develop and evaluate hybrid, battery and fuel cell powertrains for automotive applications."