The real facts on 'dirty' diesels

Diesel cars, once seen as a solution to help the UK reduce its CO2 emissions, have recently become ‘demonised’ for their nitrogen dioxide and particulates output.

The debate has left many confused and unsure on how to view diesels, both old and new.

Here, we tell you everything you need to know about the current state of diesel and the events leading up to this point – and, as we look past the headlines, some of the findings may well surprise you.

UPDATE: How will the Autumn Budget diesel tax change affect me?

Contents 

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Should diesel be a dirty word? The diesel timeline

Here’s where it all began from the heyday of diesels up to where we sit on the matter presently.

Diesel cars timeline

READ MORE: Engine idling - why it's so harmful and what's being done

With the growing negativity around diesel cars, many diesel owners have questions that need answers - read on to find out where you stand, as a diesel driver.

Diesel cars: what you need to know

  • Do I need to get rid of my diesel?

    This depends on how future government and local policy is implemented. Outside London, the Government hasn’t yet put anything concrete in place to penalise drivers for owning diesel vehicles, nor has it implemented any schemes to incentivise drivers to trade them in either.

    In London, however, the Mayor will be introducing a T-Charge and an Ultra-Low Emission Zone to reduce air pollution.

    But as part of the Government’s air quality plan, which includes banning the sale of new diesel and petrol vehicles by 2040, it is possible charging Clean Air Zones, similar to ones in London, could be rolled out in other cities which have been identified as having some of the worst air pollution in the country.The implementation of these may be a few years away, but at present only diesel vehicles that meet the Euro 6 emission standard will be safe from charges. The Government hasn’t put in place any schemes to incentivise drivers to trade in their old diesels.

    Vehicle manufacturers, however, have announced several schemes to urge drivers to trade in older vehicles for new ones.

  • What can I do to help, if I can’t afford to buy a new car?

    Some manufacturers are creating their own diesel scrappage schemes that offer thousands of pounds towards a new car if you trade in an older diesel one. While money off a new car is helpful, it won’t be enough of a discount to encourage everyone into a new car. For many drivers, a new car simply isn’t an option because of
    the costs involved.

    For buyers of used cars, the best advice to reduce your environmental impact is to choose the newest car you can afford as these are more likely to meet modern Euro emissions standards.

    However, how towns and cities that bring in clean air zones will treat vehicles is still to be confirmed.

    You can also think about where and when you drive. High levels of pollution are predominantly (but not exclusively) a problem in city centres, so changing your
    route to avoid entering future ultra-low emission and Clean Air Zones may well make a difference.

  • Is it OK to buy a modern diesel?

    For those drivers who use their vehicle for long journeys, diesel remains the default choice, for its better fuel economy. A modern Euro 6 standard diesel should be almost comparable to that of a petrol car in terms of NOx emissions – while diesels still
    emit, on average, up to 25 percent less CO2 than petrols cars, however, real world driving emissions may still vary.

    In the short term at least, drivers of Euro 6 diesel cars should be exempt from any charges or restrictions as a result of clean air zones.

    The Government has, however, promised to look at the appropriate ‘tax treatment’ of diesels in November’s Budget, so there remains a question mark over how newer diesels might be impacted by this.

  • Are all diesels bad?

    Newer diesels tend to emit lower levels of CO2, however there are question marks over whether these newer vehicles in real-world conditions emit as little NOx and particulates as the laboratory tests suggest.

    New real-world testing standards were introduced in September 2017, which should give buyers more information on how much their new diesel may emit. Drivers
    might also like to look at the EQUA Index as another source of information on emissions.

    Generally speaking, older diesels, doing high mileage in urban areas tend to be the biggest cause of pollution.

  • How can you choose a clean diesel?

    This can vary by make and model so it is always good to do your research.

    As a general rule of thumb, diesel cars which were introduced from 1 September 2014 on
    new-to-market cars, and the majority of new cars sold from 1 September 2015, are Euro 6 compliant – although there are some exceptions and without a
    comprehensive online look-up system yet available, you are best checking directly with a manufacturer to be sure of a vehicle’s Euro emissions class.

  • Are diesels’ days numbered?

    In the long term yes, because the Government has announced that new diesels will no longer be sold from 2040. But this also applies to petrol vehicles.
    In the more immediate term it is hard to be conclusive – at least until the Government is clear about how it will treat diesel vehicles, and until local authorities’ plans for clean air zones are approved.“We are on a journey to a new zero emissions future and the latest high-tech diesels in our cars are just an important step on that journey.”

  • When should I pick diesel?

    Choose a modern diesel car if you mainly drive on motorways and rarely drive short distances.

    Generally speaking if much of your driving is in urban and typically more congested areas, it may be better to opt for a vehicle other than a diesel. At present there are no plans to charge Euro 6 diesel vehicles to drive into city centres, however, this may change in future years.

  • When should I pick petrol?

    Choose a modern petrol car if you live in the city and mainly use your car for short trips, particularly if you do occasional longer trips by motorway, and most of your driving is in slow-moving, heavy traffic.

    Also pick petrol if you love driving – today’s modern turbo petrol engines are huge fun and reasonably efficient with it!

  • When should I pick alternatively fuelled vehicles?

    There are now other options open to motorists. These include conventional hybrids and plug-in hybrids.

    Pure electric vehicles are also becoming increasingly popular, which are ideally suited to driving around city centres where there is plenty of charging infrastructure to keep you moving.

    Plug-in hybrids and conventional hybrids are good for people doing a mix of city centre driving and longer journeys.


MORE ADVICE: What is my car's Euro emissions rating?

Diesel car charges

Dirty diesel cars

There are some existing charges in place to penalise drivers with older cars, both petrol and diesel.

London T-Charge

The London ‘T-Charge’ (or ‘Toxicity Charge’) goes live October 23 2017. Operating in the same area as the London Congestion Charge, it will impose a £10 surcharge on owners of the oldest, most polluting vehicles, in addition to the Congestion Charge.

The charge will be imposed vehicles that do not meet Euro 4 emission standards, both petrol and diesel models.

More on the London T-Charge

London's Ultra-Low Emission Zone

Already scheduled to come into force in September 2020, the current Mayor of London is proposing to bring forward the Ultra-Low Emission Zone (ULEZ) forward to April 2019.

This will charge the most polluting vehicles £12.50 to enter the zone and will cover the same area as the London Congestion Charge. It will operate 24 hours a day, 365 days of the year.

All diesels apart from the latest Euro 6 models will be affected; petrol cars will be hit by the charge too, but the Mayor of London’s office has deemed Euro 4 standards acceptable for petrol cars, due to their lower NOx emissions. The London ULEZ will replace the T-Charge.

More on Ultra-Low Emission Zones

Diesel car charges outside London

Other major cities suffering illegally high levels of pollution must develop plans to tackle the problem, as set out in the Government’s clean air proposals. These may or may not see drivers face charges.

READ NEXT: Diesel scrappage schemes – a simple guide