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Turbo hybrid makes debut

Posted on 09 October, 2014

A new type of emissions-reducing and fuel-saving technology has been unveiled by Kia Motors in Paris. It marries diesel and electric power with an electric supercharger and turbo – and could make future hybrids more efficient and affordable. The technology for the Optima T-Hybrid concept, which stands for turbo-hybrid, is still in its development phase, but being showcased in a current production vehicle indicates it has practical applications. In place of a petrol engine, the concept makes use of the 1.7-litre turbo-diesel unit available in the Optima in Europe, which is paired with a small electric motor powered by a 48-volt lead-carbon battery pack. Described as a mild hybrid powertrain, it enables the car to be driven in electric-only mode at low speeds and when cruising, while deceleration recharges the battery pack. Kia has chosen lead-carbon batteries because, unlike lithium-ion batteries, they require no active cooling and are easier to recycle at the end of their life. In heavy traffic and on urban roads, the T-Hybrid powertrain features a zero-emissions stop-start system. Using a belt-driven starter generator instead of a conventional alternator, the engine can restart with almost no noise or vibration. A smaller starter motor and starting battery also help to reduce its weight. The battery supplies energy to an electric supercharger on the diesel engine, increasing torque and power at low engine speeds. The conventional turbocharger takes over to provide greater power and torque as engine speeds rise. Kia says the T-Hybrid powertrain offers greater performance and lower running costs while cutting harmful exhaust emissions. It’s targeted as being a more affordable green option than conventional petrol-hybrids. Performance and fuel consumption figures have yet to be released, but the marque says the powertrain is expected to deliver a power increase of 15-20 per cent. Plans to mass produce the technology have yet to be confirmed.