The Hospital Group has replaced its fleet with Proton Gen-2 ecoLogic dual fuel cars, which can run on LPG or petrol.

With 180 cars that cover on average 100,000 miles per year, Proton said the company will save up to £65,000 per year in fuel costs.

Humberside police force has been running LPG converted Proton vehicles for over 10 years and, with just over 300 on its fleet, has saved over £300,000 on fuel costs per year.

Alan Hocking, from Humberside Police, said: "We began trialling LPG vehicles in 1996 and we've never looked back.

"Seventy per cent of our fleet that run on LPG are Proton vehicles and we encourage our drivers to run on LPG 90% of the time if possible.”

Simon Park, general manager sales and marketing for Proton Cars said: "For fleet managers, the vast cost savings on fuel are a compelling reason for businesses to consider the Proton Gen-2 ecoLogic when purchasing fleet vehicles.”

At £9,995, the Proton dual-fuel is priced the same as its petrol equivalent.