Deciding whether a diesel or a petrol powered car is the more economical choice for you is not a simple decision and purchase price is only one of many factors to consider. If you choose two almost identical cars, one petrol and one diesel, you are likely to pay a premium for the diesel model.
For example a 5 door Focus 1.6 Ti-VCT Petrol costs €20,295 while a similar 1.6 TDCi Diesel will set you back €21,935, representing a difference of €1,640.
Tip 1: Petrol cars are cheaper to buy.
Whether or not this initial investment will make sense really depends on the amount you travel each year. For example, by driving 18,000 km per year it would take an average of 4 years for the additional cost of a diesel to be recouped. As a general rule of thumb if you drive fewer than 18,000 km a year or if the majority of your driving is in a city environment, a diesel car is not for you as the amount saved at the pump over the duration of your car ownership may not outweigh the initial premium or the additional maintenance costs.
The average price of petrol in Ireland at present is €1.44 per litre and around €1.34 for a litre of diesel. It will cost less to fill your diesel car and you will make fewer trips to the pumps overall as the fuel economy will generally be better. However, in order to make an informed choice you need to know the prices of petrol and diesel in your local area, the fuel consumption of your engine options and how much mileage you will cover each year. It is also worth noting that fuel prices fluctuate considerably.
Tip 2: Diesel costs less per litre and diesel engines generally have lower fuel consumption.
For example, if you were to drive 20,000 km per year and were considering a diesel car that costs €30,000 and typically consumes 4.5l/100 km. The alternative option is a petrol version that costs €28,000 and will consume 6.0l/100 km. The diesel car would require an average of 900 litres of fuel at €1.34/annum. This equates to an average annual bill of €1,206. The petrol car would consume 1,200 litres of fuel at an average cost of €1,728. Using these figures it would take 4 years to recoup the additional €2,000 spent to purchase the diesel version.
Tip 3: Running Costs. As diesel engines tend to be more efficient than their petrol counterparts motor tax is usually lower. However, insurance for diesel models can be more expensive as the car's value is higher. Using the Ford Focus as mentioned above as an example will show that the petrol version will cost €280 per year to tax whereas the diesel version is just €190 per year.
Tip 4: Maintenance and depreciation. Diesel cars tend not only to be more expensive to buy than their petrol counterparts but will also cost more to service and maintain as the service intervals tend to be shorter. However, the demand for diesel cars is high in the second hand market so you may find less depreciation with a diesel model.
Tip 5: Choice of car. While most cars will come with both petrol and diesel options some are better suited to one fuel type over another - for example a 4x4 SUV will tend to be most sought after in diesel whereas a sports car will usually be petrol powered.
So how low can you go? As car makers work at a fevered pace to reduce fuel consumption new cars are more economical then ever
The latest diesel can rival hybrids for efficiency. Peugeot's 208 1.6-litre BlueHDi: Due here next month Peugeot's 208 1.6-litre BlueHDi 100bhp Stop Start, recently set a new long-distance fuel consumption record at a test circuit in Belchamp, France. Some 2,152 kilometres were covered on just 43 litres (9.45 gallons) of diesel, with an average fuel consumption of 2.0 l/100km (141.2 mpg).
VW Golf Bluemotion: The most economical Golf ever the Bluemotion option takes frugal hatchbacks to a new level. With Co2 emissions of 85g/km and fuel economy of 3.2 l/100km (88.3mpg) this is a car that will make your lawn more look thirsty. The fuel economy in petrol cars has also improved considerably in recent times.
Ford Fiesta 1.0 EcoBoost 65PS S/S: Super to drive, very stylish and very economical the Fiesta and Ford's renowned EcoBoost engine is a very frugal combination.
This petrol car returns 4.3 l/100km ( 66 mpg) on a mix of motorway and urban driving and Co2 emissions are just 99g/km. There's even an EcoBoost version in the flagship Mondeo model.
Renault Captur 0.9 TCe: Renault's Captur is essentially a Clio on steroids, with chunkier SUV styling it shares styling features with its smaller sibling including a wide black grille and sharper and more aggressive-looking headlights.
The Captur returns 5.0 l/100km (56 mpg) on a combined and CO2 emissions are 114g/km.