Comparing the running cost of an EV to a Petrol and Diesel



In many ways owning and driving an Electric Vehicle (EV) is a very different experience from a petrol or diesel vehicle and yet no different in other ways. Manufacturers are now releasing electric versions of their best selling models and selling them alongside their petrol and diesel versions. Best selling models such as the Golf, Focus are now being released as a full electric option, ending some motorists idea of electric cars being a 2 seater  mini car only suitable for short city charge

At present most manufacturers are releasing either a Hybrid or Electric model into their range. This can be seen as the manufacturers way of showing it’s capability within the sector and an indication of their intent for the future of the industry. Either way, the progression and development of the EV sector promotes the benefits of driving an electric vehicle while educating the public, unaware of it’s ability as a credible form of transport.

Below we show a comparison table for running an Electric Vehicle against a Petrol or Diesel equivalent.

An EV with a fuel efficiency of 150Wh/km (or 1.5L/100k or 188mpg) travelling an annual distance of 16,000km will produce the following annual fuel cost savings:

  • €797 pa with respect to an equivalent Diesel or 80% saving
  • €1,264 pa with respect to an equivalent Petrol 86% saving

In terms of annual CO2 savings, the following savings will occur:

  • 523 kg per annum of CO2 with respect to an equivalent Diesel or 27% saving
  • 683 kg per annum of CO2 with respect to an equivalent Petrol or 33% saving

The Example below illustrates how these figures are derived. It is assumed that the Consumer is charging 100% of the time at their own Domestic location.

Please note these figures are illustrative only and final figures will depend on usage, driving style, weather, energy prices and chosen electricity tariffs.

EV Fuel Cost Comparison Example
Units BEV Petrol Diesel
Combined Fuel Efficiency 150Wh/km  (or 1.5L/100km) 7L/100km 5L/100km
Annual Mileage km 16,000 16,000 16,000
Annual Fuel Requirement Litres n/a 1,120 800
kWh 2,400 n/a n/a
Energy Prices per unit (inclusive of all VAT, Duty, Levy and Carbon Tax) Euro/Litre n/a 1.31 1.25
Euro/kWh1 Urban 24hr2, 3 = 0.1600Night Saver2, 3 = 0.0846 n/a n/a
Annual Fuel Cost Euro Urban 24hr = 384Night Rate = 203 1,467 1,000
Maximum Annual EV Fuel Cost Savings Euro —– 1,264 797
% 0 86% 80%


  1. 1. Electricity prices are those price inclusive of VAT @ 13.5%, these prices represent the additional cost on the existing Electricity Bill for the additional energy units, all PSO levies and Standing Charges remain unchanged unless the Consumer is switching Tariffs
  2. 2. Note there is no specific EV Tariff yet available for Domestic electricity supplied for an EV, if the Consumer switches Tariff from a 24hr Urban to a Night Saver Tariff, note that the Standing Charge and Day Rate prices of electricity will rise.  Although there is no cost for switching Tariffs, there may be a metering cost involved in switching back at a future date.
EV CO2 Emission Comparison Example
Units BEV Petrol Diesel
Direct CO2 Emissions (ie Direct for EV) g/km 0 130 120
Indirect CO2 Emissions from Electrical Grid1 g/kWh 582 n/a n/a
Annual Electricity kWh 2,400 n/a n/a
Annual Mileage km 16,000 16,000 16,000
Annual Direct CO2 Emissions Kg 0 2,080 1,920
Annual Indirect CO2 Emissions kg 1,397 n/a n/a
Annual CO2 savings kg —– 683 523
Annual EV CO2 Savings % 0 33% 27%


Based on SEAI “Energy in Ireland – 2009 Report” average electricity generation mix, note that this CO2 intensity will continue to fall as Ireland’s Renewable Electricity content rises from the value of 14.4% in 2009 to 40% by 2020

Information Source- SEAI