It means customers who choose the larger 85kWh battery pack, which so far is the more popular unit, get an unlimited mileage warranty on the entire drivetrain. The 60kWh battery has a 124,000-mile cap, but is otherwise also valid for eight years.

Unusually, the warranty covers damage from improper charging procedures and battery fires, even if these result from driver error. The rest of the car is backed by a four-year, or 50,000-mile warranty.

Announcing the warranty extension on the Tesla Motors blog, chief executive and co-founder Elon Musk said: ‘In hindsight, this should have been our policy from the beginning of the Model S program. 

‘If we truly believe that electric motors are fundamentally more reliable than gasoline engines, with far fewer moving parts and no oily residue or combustion by-products to gum up the works, then our warranty policy should reflect that.’

Extending the warranty reserves is expected to have a slightly negative effect on Tesla’s short term earnings, Musk added, but should pose no long-term problems.