We are continuously carrying out important safety and durability tests for the electric Lightning. Whilst we are confident of our figures, further analysis may require design changes that affect the final specifications. Consequently we reserve the right to change the design and specification without prior notice. Electric power charge costs have been based on 37kW battery in one hour on standard household single tariff of 10.76pence/kWh. Petrol engine version cost per mile has been based on 18mpg performance and £4.75/gallon price for petrol.