Driving down the cost

New generation UK dual mode brings affordable hybrid engines a step closer.


In line with the chancellor’s low-carbon aspirations announced in his pre-Budget report, a UK-made diesel/electric engine that is claimed to provide all the functionality of existing systems at a fraction of the cost could be set to help hybrid cars fall in price.

Developed by Zytek, the Midlands firm behind the A1 Grand Prix engine, the hybrid engine has been developed in response to the government’s Ultra Low Carbon Car (ULCC) initiative, an effort to stimulate car makers to produce affordable, low-emission family vehicles.

This £10m initiative, launched in 2003, threw down the gauntlet for manufacturers to develop a prototype family car, capable of 0-60mph (100kph) in 16 seconds and produce CO2 emissions of less than 100g/km.

Earlier this year (The Engineer, 19 June) Citroen unveiled Efficient-C, a modified Berlingo Multispace which, with a little help from Ricardo, used a hybrid diesel/electric engine, to reduce emissions to 99gm/km. But the Zytek engine, launched last week in London aboard a modified Smart ForFour topped this with claimed emissions of just 85gm of CO2 per km.

Talking at last week’s launch, transport minister Dr Stephen Ladyman said: ‘Zytek has met the ULCCC challenge in a way that is adaptable to any vehicle.’

Zytek’s ULCC project manager, Neil Cheeseman, said that the vehicle utilises a hybrid powertrain based on a 1.5 litre, three-cylinder turbo-charged diesel engine coupled with two high-efficiency permanent-magnet electric motors.

Although there are around 200 different hybrid systems at varying stages of development, there is still a requirement for a hybrid engine that combines good functionality with low cost and simplicity. Cheeseman claimed that Zytek’s engine fits neatly into this niche.

Most of today’s passenger car production hybrids are either parallel or series systems. Series hybrids offer high efficiency at low speeds, while parallel hybrids have the combustion engine permanently coupled to the wheels and are more efficient at high speeds. A new generation of dual-mode systems are able to exploit the advantages of both series and parallel modes, but are generally more complex and more expensive.

Cheeseman explained that Zytek’s dual-mode hybrid eliminates many of the compromises inherent in these systems by using a sophisticated control system to replace clutches and complex epicyclic gearsets. He said that as well as providing the many advantages of dual-mode operation, this helps to reduce component count, eliminates wearing friction surfaces, reduces packaging volume and substantially cuts manufacturing costs.

While the vehicle will run as a series hybrid around town, it works in parallel around town while travelling at high speed. The vehicle’s 288V lithium-ion battery, developed by Lithium Technology, can be charged by either the internal combustion engine (ICE) or by using regenerative braking. The system can also be plugged in and topped up overnight using off-peak power. Cheeseman said that using this method, a 16-mile (26km) journey across London’s extended congestion charge zone would cost just £0.08p.

According to Steve Tremble, Zytek’s sales and marketing director, the company is now in discussions with a number of leading automotive OEMs, including Tatuus, and hopes to be able to license the technology for mass production.