Over the last few years, you’ve probably heard a lot of negative things about diesel cars. From the Volkswagen emission scandal to the Government’s new anti-diesel agenda, it’s been non-stop bad news for the best part of two years.
If it's time to choose a new car, I wouldn’t blame you for discounting diesel cars entirely. (While I wouldn’t blame you, I’d still think it was a huge mistake.)
Yes, Volkswagen did some dodgy emission stuff. And yes, the Government have changed their mind on whether they like diesel. (They don't.) But there are still outstanding diesel cars on the market that deserve your consideration.
In this car fuel blog, I’ll run through all the major considerations you should make before deciding whether or not to go for a diesel.
When you ask people about diesels, they typically bring up two things: Fuel Efficiency and Emissions. I’ll deal with fuel efficiency in a minute, which leaves emissions to discuss now.
Like this most things, diesel emissions are fair complex.
The Society of Motor Manufacturers and Traders (SMMT) says that diesel cars emit less CO2 than their petrol equivalent. On average, a petrol will emit 200g CO₂/km and a diesel will emit 120g CO₂/km.
Unfortunately, CO2 isn’t the only gas that comes out a diesel car’s exhaust pipe.
Heating air inside an engine produces a group of gases called nitrogen oxides (NOx). This group includes nitrogen dioxide (toxic), nitrous oxide (greenhouse gas) and nitrogen oxide which reacts with water to form nitrogen dioxide (toxic). In short, a lot of fairly nasty stuff.
While petrol cars also produce nitrogen oxides, they emit far less than diesel engines.
So, diesel engines emit less of one harmful gas and more of a different one.
Low Emission Zones
The government is getting increasingly concerned about the air quality in major cities and that’s leading to low emission zones being rolled out across major metropolitan centres.
London has recently introduced a new ultra low emission zone in place, which levies an entry charge on vehicles based on their emission standard. This zone is much stricter than its old low emission zone, which only targeted the most polluting vehicles.
There’s also a Clean Air Zone planned for Birmingham, which comes into force next year and charges polluting vehicles up to £100 per day to enter.
There’s also a similar zone planned for Glasgow, which comes into force in 2022 and also targets vehicles based on emission standards.
Beyond that, there are maybe a dozen more zones in the works and countless more being proposed.
These zones either target diesel cars specifically or set restrictions that are harder for diesel cars to pass.
The government recently announced that the sale of new petrol and diesel cars would be banned from 2040. In Scotland, the deadline is 2032.
With similar bans popping up all across the world, manufacturers will be spending less time on diesel technology and more time on hybrid and electric cars.
Whether that affects your buying decision right now is completely up to you.
Also, remember that the ban doesn’t cover existing cars. If you buy a car today and it’s still running in 2040, you can keep driving it.
Long Distance Driving
We all know that diesel cars are more efficient than their petrol equivalent. But with a higher list price and running costs, you can quickly lose all the money you save at the pump.
If you travel more than 12,000 miles per year, you’re usually better off with a diesel as the better fuel economy outweighs all the additional fees and payments. Below 12,000 miles per year, you’re often better to pick up an efficient petrol car and pay a little bit more at the pump.
Larger Cars and Towing
Due to the way they work, diesel engines are much better at moving heavy loads. So, if you’re looking at a large bodystyle (SUV, 4x4, estate, etc.) or you’re planning on towing something, you’re usually better off with a diesel.
This is because diesels operate at much lower revs and have a lot more torque down low. If you put a petrol engine in a Land Rover, you’d need to aggressively rev it to get the 4x4 off the starting blocks.