The current Volt can travel around 87km on battery power alone before a 1.4 litre four-cylinder naturally-aspirated petrol engine kicks in to maintain the battery's charge.
As the petrol engine's job is largely to assist the electric motor and battery pack, the emerging industry trend has seen three- or even two-cylinder engines used to maximise efficiency while saving space and weight.
GM will buck this trend by increasing the Volt’s petrol engine capacity to 1.5 litres, but the global carmaker says it will be more efficient than the 1.4 litre unit it replaces.
The Volt’s electric-only driving range is also set for an increase, thanks largely to an all-new battery pack capable of storing more energy using fewer cells.
The new model will use just 192 cells in place of the existing Volt’s 288, helping the battery pack shed 13kg over its predecessor.
Improved battery tech means the Volt will have an extra 20 percent energy storage capacity, but whether that translates to a 20 percent improvement in electric-only range (from 87km to 104km) is unclear.
The 20 percent figure is exactly what then-GM Boss Dan Akerson ‘predicted’ in August last year, suggesting GM had already achieved such an improvement, or that anything less than 20 percent was unacceptable for the new model.
The Volt’s electric motors have also been on a diet, weighing 45kg less than in the current model. They’re also five to 12 percent more efficient to operate, while offering up to a 20 percent improvement in acceleration.