Diesel Vs Electric Cars – Which Is Better?

Diesel cars tend to have a more affordable asking price than electric cars and have better torque (power) for increased performance and towing. However, EVs are cheaper to run, plus they often feature better onboard technology and are better for the environment.

Want to find out whether a diesel or electric car is right for you? Read on to see which is best for your budget, driving style and the environment.

Which is cheaper, diesel or electric?

Electric vs diesel cars

See our table below for an idea of the price difference* between popular diesel and electric cars.

*Purchase prices based on new models using the manufacturer’s RRP. Electric prices include the government’s £3,000 plug-in grant.

The initial asking price of diesel cars is often cheaper than electric models because of how expensive it is to produce the large batteries in EVs. A lot of costly sourcing of raw materials is needed for this process, and extraction isn’t cheap. Neither is the battery pack production afterwards, both of which aren’t at the same level as the supply chain for fossil fuel vehicles.

On top of this, EVs feature a lot more advanced technology systems as standard because most manufacturers have still only produced a single all-electric model. Unlike diesel cars which can be cheaply produced en masse and have cheaper trims available, all the eggs tend to be in one basket with electric cars. When there are variations for an EV, like in the Renault Zoe, these tend to be performance improvements – i.e. a more powerful motor on the GT Line model than in the other two.

Are diesel or electric cars worse for the environment?

If you’re concerned about how much CO2 emissions your car releases while you’re driving, there isn’t a better choice to put your mind at ease than an electric car. They don’t have an internal combustion engine (ICE) like diesel models do, nor is there a tailpipe at the back which emits harmful greenhouse gases into the atmosphere after the fossil fuels are burnt.

According to the latest figures from the European Environment Agency, the average CO2 emissions of a diesel car is 121.5g/km, nearly one and a half times more than the EU’s 2020-21 target of 95g/km for all new cars.

Despite electric cars producing higher emissions at the point of manufacturing, a study by the Union of Scientists using the Nissan Leaf and Tesla Model S found that total global warming emissions from EVs are about half that of a gasoline car over a lifetime.

You also have the case of noise pollution too. Diesel cars tend to have even louder engines than petrol models due to them running at higher pressures during combustion. On the other hand, electric cars are almost silent as they run on battery and motor power which delivers instant, seamless acceleration.

Diesel fuelling vs electric charging

diesel vs electric

When you’re weighing up the decision of whether to choose a diesel car or electric car, you should consider which ‘fuelling’ method is more cost-effective based on your driving habits.

Because charging an EV takes considerably longer than filling up at a station, it’s also important that you identify what your charging options are in order to have the most efficient option for running the car.

Cost

Diesel is the most expensive type of fuel you can put in a car because of higher taxation it receives due to its perceived ‘dirtiness’. Another reason is that diesel cars are declining in popularity as the surge in popularity of electric vehicles and small-engined efficient petrol models continues.

Electric cars receive much of their plaudits due to their very cheap charging costs. This is mostly thanks to the broadening of the infrastructure for EV chargers and widespread availability of electricity. For example, the average model with a 200-mile range costs around £8 to charge at home, or about £6.50p at a rapid charger for 100 miles charge.

In some cases you’ll be able to make use of free charging, which can be found at workplaces or supermarkets.

On the other hand, the average price of diesel is £1.15p per litre. The Kia Ceed diesel model, which has a 50-litre tank, would set you back £57.50. This would get you 796.4 miles based on the car’s fuel economy (72.4mpg) but to get the same 200 miles from fuelling up you would need to spend £25.80p.

Remember: You’ll need to factor in the cost of purchasing and installing a home car charger if you want to charge an EV from home. This costs around £449 with the government’s £350 OLEV grant.

Time it takes

The time it takes to charge an electric car depends on where you decide to charge it. This can take you as long as seven hours (overnight home charging) or at best 30 minutes (rapid charging at a public charging station).

If you qualify for a home charging point to be installed at your house, you won’t have to worry about standing around and waiting at a public charger. It’s also much better for the car’s battery health, as opposed to regular rapid charging which can damage cells and reduce the car’s ability to hold a charge if used regularly.

Despite the increasing availability of EV chargers, filling up a diesel car is a much quicker process. It takes as little as five minutes to put a full tank of fuel in a car and pay for it. So, if you do a lot of long-range journeys (i.e. 200+ miles in one day) during the average week, a diesel car might be a better option for you. At least until the availability of affordable EVs with plus-200 mile ranges becomes widespread.

Efficiency

electric car efficiency

Electric powertrains have been proven to be significantly more efficient than diesel engines.

There are three main reasons why this is the case.

  1. Electric cars don’t suffer from idling fuel losses like diesel cars do.
  2. Most EVs have what’s known as ‘regenerative braking’, whereby energy is gathered by the electric motor when slowing down, and is then provided as additional charge to the battery.
  3. Unlike diesel cars, there’s no risk of wasting energy through inefficient gear selection. These cars are single-speed and deliver instant torque when you accelerate.

Electric car fuel efficiency is most commonly measured in terms of Wh/mile (watt-hour per mile) which represents how much energy a one-watt device uses in an hour.

As an example, the Hyundai Ioniq’s fuel consumption is about 245Wh/mile. To show what the equivalent of this is in terms of a diesel car’s miles per gallon, you need to divide the total energy in a gallon of diesel fuel by the Wh/mile of the EV.

So, this would look like:

40,736Wh (avg. energy per gallon of diesel) ÷ 245Wh

= 166mpg

What driving style is best for diesel and electric cars?

Electric cars aren’t renowned for their abilities to cruise comfortably on the motorway. Many of them have a top speed of around 93-96mph, but they don’t seem to have the real ‘umph’ at these higher speeds that comes with diesel cars. This is mostly down to the fact that you can make use of multiple gears in diesel models to generate more torque when you’re driving faster.

If you only tend to drive short distances each day on local roads, this is where you’ll find an EV come into its own. A lot of electric cars are fun to drive at urban speeds because they accelerate quickly and tend to have shorter turning circles, plus responsive handling.

Advantages and disadvantages of an electric car

Advantages

  • Cheap running costs (especially charging)
  • Zero emissions and minimal noise pollution
  • Government grants for purchase price and home chargers
  • Quick acceleration, fun to drive in urban environments
  • Low maintenance costs due to fewer moving parts
  • Good residual value

Disadvantages

  • High asking price
  • Limited by range
  • Charging can take time
  • Questions surrounding how ‘green’ they are (i.e. battery recycling issues and fossil fuels being used to generate electricity)
  • Can be more expensive to insure than diesel cars due to costs of repairs

Advantages and disadvantages of a diesel car

Advantages

  • More efficient than petrol, so fuel prices can be less (provided they stay close to petrol ones)
  • Lower CO2 emissions than most petrol models – good for cheaper road tax and for those conscious of the environmental impact of their cars
  • Less depreciation than petrol cars
  • Greater torque and pulling power – ideal for increased performance and pulling trailers
  • Diesels can run on various fuel types besides conventional diesel fuel – biodiesel could be salvation for these cars in the future

Disadvantages

  • Don’t have the impressive zero emissions of electric cars
  • Need to be driven long-distance regularly to prevent build up of particles in the diesel particulate filter – this can be a costly repair if it causes damage
  • Volatile fuel prices
  • Diesel engines aren’t as reliable as the simple electric drivetrain setup

5 best all-round electric cars

  1. Nissan Leaf
  2. Hyundai Ioniq
  3. Kia E-Niro
  4. Renault Zoe
  5. BMW i3

5 best all-round diesel cars

  1. Ford Fiesta 1.5 TDCi
  2. Honda Civic 1.6 i-DTEC
  3. Mercedes-Benz A-Class A180d
  4. Citroen C4 Cactus 1.5 BlueHDi
  5. Kia Ceed 1.6 CRDi 

Want a great price on a new diesel or electric car? Why not consider leasing one? Compare prices now on our special offer lease deals for the best offers.

Want to find out more about electric cars before making a decision? Head over to our electric and hybrid car guides to learn more.

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