All-electric cars with the range of modern day petrol or diesel-equipped engines are still 20 years away, says Mercedes-Benz research and development boss Thomas Weber.
Electric cars for city driving are just around the corner and technology exists to run a car for up to 120 miles without a top up. Getting to twice or three times that is still some way off, he said.
Weber, who is member for the board of Mercedes parent Daimler, responsible for R&D, said that while Mercedes develops EVs, it will continue to improve conventional petrol and diesel engines and sees hybrid technology as the next development towards zero emission vehicles.
Weber said: "Hybrids offer great potential in terms of their flexibility. Pure electric vehicles are still constrained by range and there many issues still to address in terms of weight and cost. Hybrid technology has now been well-established by the Japanese makers and at last week's Frankfurt Show we showed the full range of our own hybrid technologies.
"Before we see full electric cars or fuel cell vehicles we need to establish infrastructures. Topping up batteries is straightforward if we charge vehicles slowly overnight. But we need to look at charging stations and how we can top batteries up in much shorter timescales, and this requires investment to upgrade the grid. Similarly with hydrogen fuel cells we will need hydrogen filling stations."
Weber said that there are still many gains to be made in terms of fuel consumption and carbon dioxide reduction with existing engines and transmissions.
Mercedes is currently developing smaller engines which could one day see turbocharged 4-cylinder engines in big, luxury S-Class models.
"Downsizing is not necessarily about smaller cars," he added. He also reveals that all Mercedes cars will have stop-start systems available. "The roll-out has already started."
Weber says Mercedes will also continue to focus on safety.
He said: "Our goal remains the accident-free vehicle. Every customer only has one life and we are looking continuously not only on crash performance, but on avoiding collisions in the first place."