The models, which are the first Fiat Chrysler Automobiles (FCA) city cars to be fitted with new petrol mild hybrid technology, start from £12,665 and £13,855 respectively.
Hybrid Launch Editions can be identified by the ‘Hybrid’ logo on the rear and the ‘H’ logo on the car’s centre panel. Priced from £16,795 for the 500 and £14,385 for the Panda, they feature exclusive exterior paint colours and interior fabrics.
Highlights include seats which Fiat says are the first in the automotive sector to be made of Seaqual Yarn – a material derived from recycled plastic – and a new and exclusive Dew Green colour.
Both city cars utilise a 1.0-litre three-cylinder engine and a 12-volt starter motor with a lithium battery. Power output is rated at 69bhp, while torque stands at 92Nm.
Fiat claims the mild hybrid versions of the 500 and Panda can achieve 53.3mpg and 49.6mpg respectively on a combined cycle. CO2 emissions are said to be 88g/km for the 500 and 89g/km for the Panda.
The Fiat 500 Mild Hybrid will arrive in UK showrooms from February 2020, while the Panda Mild Hybrid will come a little later in March.