Is diesel actually better for the environment?

With the UK not expected to fully switch to electric until 2040, and electric cars still unsuitable for many drivers due to range anxiety and charging issues as it currently, there’s still more than half a tank left in this debate.

We know diesel still has plenty of advantages for the long-distance driver, but has the anti-diesel campaign damaged the diesel reputation so much that it's now having an effect on our environment?

We examine the diesel debate, focusing on how it still can be a better choice for the environment. First let's look at the history of the argument.

What is the ‘anti-diesel agenda’?

These days, it feels barely a week goes by without another story in the media that seems to demonise diesel.

A lot of these articles are fuelled by the somewhat contradictory advice issued by the government over the last decade or so.

Under Gordon Brown, the Labour government offered incentives for motorists in a bid to get them to switch to diesel.

By summer 2016, the Government’s Clean Air Strategy announced proposals which allowed local authorities to begin implementing Clean Air Zones, which included the possibility of charges being levied to enter specified urban zones if your diesel vehicle did not conform to Euro 6 emissions standards.

Later in 2017, Chancellor Philip Hammond announced a tax hike on all new diesel vehicles that don’t meet Euro 6 RDE2 standards.

Policy moves like this, and the subsequent fanfare around them, form what some commentators call the ‘anti-diesel agenda.’

You can view a graphic of the full diesel debate timeline here.

What impact is this having on the diesel market?

A report by the Society of Motor Manufacturers and Traders (SMMT) published in early 2018 claims that inconsistency in government messaging over diesel vehicles has led to a dramatic decline in sales.

In June 2018, sales of diesel vehicles declined for the 14th consecutive month, leading to fears that the industry is in terminal decline.

In its report, the SMMT called for “consistency from government in messages to consumers and long-term incentives to deliver shared ambitions on climate change”.

READ: Climate activists let down on SUVs

Are diesel cars better for the environment?

The steady decline in sales of diesel vehicles in the UK may have attributed to the average carbon dioxide emissions from new cars actually rising by 0.8% in 2017.

This increase came despite the UK needing an annual reduction of 5.9% to meet the current overall CO2 reduction targets set for 2021.

In its advice on cars and fuel options for motorists, the Department for Transport (DfT) states that diesel vehicles have significantly lower CO2 emissions per kilometre travelled due to their higher efficiency.

The DfT advice goes on to suggest that diesel engines have a lower, though still significant, impact on climate change.

As a general rule, due to constant technological advances and updated EU emissions regulations, the newer the diesel vehicle is, the greener the engine is.

This is backed up by a report by scientists from the University of Montreal, which states that the modern technologies adopted by new diesel vehicles makes them now far cleaner, particularly in relation to particulates.

So while diesel engines aren’t as environmentally-friendly as their electric counterparts, they can be seen as preferable to petrol motors from a CO2 point of view and still have an important role to play in helping meet carbon reduction requirements.

This is why you should think carefully about both petrol and diesel options before purchasing your next car.

Where air quality is a serious concern - usually in built up areas like cities, petrol will often be the better choice.

But for example, if you live in the country where air quality isn't as bad and commute long distance to work every day, it may prove better for the environment (and your pocket as far as fuel efficiency is concerned) to go for diesel with it's normally reduced CO2 output.

Read our guide on petrol versus diesel to give you a more informed idea before buying.

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What are the downsides of diesel?

While new generation diesels emit lower levels of carbon dioxide than petrol engines, they tend to emit higher levels of NOx.

In built-up urban areas, these emissions mean that diesel engines are often the biggest cause of roadside air pollution, particular among older models.

In London, these emissions have seen City Hall introduce the T-charge, which targets the oldest, most polluting vehicles on the road.

In addition to its contribution to air pollution, owners of diesel cars also face extra charges as the Government seeks to wean the public off the vehicles.

Since April 2018, motorists buying new diesel models have been subject to the VED tax hike for the first year of ownership. Your local authority may also implement extra levies on diesel vehicles, through parking permits and other road-charging measures.

What is the ‘Road to Zero?’ strategy?

In July 2018, Transport Secretary Chris Grayling announced the UK government’s new ‘Road to Zero’ strategy, a £400m plan to help boost the use of electric vehicles and electric charging infrastructure.

The strategy will pave the way for the UK’s full switch from petrol and diesel to electric from 2040 onwards. The plan would see hundreds of thousands of new charging stations rolled out across the country, while every new house could come fully equipped with its own charging point.

Although a positive move environmentally, the move was criticised in some corners by not going far enough to help drivers make the switch to electric vehicles, with the RAC calling for more to be done to address motorists’ concerns about limited range of electric vehicles and the contradictions of the new changes to the car tax system.

Does this mean the end of diesel?

If the Government sticks to its current timetable, then the sale of new diesel cars will be banned from 2040, and for all vehicles to be zero emission by 2050.

But while the move to EVs may eventually mark the demise of diesel, Chris Grayling recently said that until then, new-generation diesels could provide a better alternative for some motorists than others, especially for those who regularly drive long distances.

While diesels will eventually disappear from our streets, over the next two decades they will remain a key fixture; a choice for Britain’s motorists, and of increasing importance in a bed to drive down CO2 emissions.

Despite the growing ‘anti-diesel agenda’, there still appears to be quite a lot of juice to be squeezed from the diesel vehicle market.

Should I buy a diesel car?

This very much depends on how you use your vehicle and what you use it for. The RAC advises this more fully here.

With decades remaining before the 2040 ban hits, motorists still have a choice to make between diesel and petrol or alternatively fuelled vehicles. But to decide which is best for you, you’ll need to take a good look at your own personal driving habits.

If you tend to use your vehicle for long distance journeys on motorways or on high-speed dual carriageways, or if you require a vehicle for carrying heavy loads, a diesel vehicle will likely be your best option. Diesels emit less CO2 and are more fuel efficient, which makes them especially popular amongst fleets.

On the other hand, if you’re making a lot of short journeys in urban areas, then a petrol engine could well be a more financially-viable option than diesel.

If you’re still concerned about the environmental impacts of a fuel engine but don’t want to go full electric, then why not consider a hybrid? These are a compromise for many, as they are better suited for longer journeys than pure electric cars.

And to meet increasing demand, there are some great hybrid options on the market these days.