Currently reading: Kia mild hybrid powertrain could be ditched after dieselgate
The Korean manufacturer is considering shelving its planned hybrid diesel engine because of increasingly tight emissions legislation

Kia is considering shelving its electrically boosted hybrid diesel engine project as the Dieselgate fallout continues.

Although the project is still officially under way, Kia performance development boss Albert Biermann has admitted it is becoming hard to justify the development of more expensive diesel engines in the face of increasingly tough emissions standards.

“The research project is still going on,” Biermann told Autocar, “but the cost of electric motors and batteries in a hybrid is already significant. The question is whether it is really necessary to throw in a more expensive diesel engine.”

The research is unlikely to be wasted. Biermann suggested the hybrid system might well be re-engineered to work with a petrol engine. He said: “We also have a very efficient Atkinson-cycle gasoline engine, so I think that is the good choice here.”

The project was introduced with the Optima T-Hybrid, which was first shown at the 2014 Paris motor show. This featured the familiar Hyundai-Kia 1.7 CRDi diesel engine, which was boosted by a 48V electric supercharger - similar in principle to the one Audi has just introduced on the considerably more expensive V8-powered SQ7 TDIThis set-up worked in conjunction with a 48V starter/generator that turned it into a mild hybrid.

Kia estimated that a production version would be able to cut the emissions and fuel consumption of any car it was fitted to by 15-20%. 


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The Kia Optima has looks, practicality and value on its side. But in a class of talented models, it is an also-ran.

Mike Duff

Mike Duff
Title: Contributing editor

Mike has been writing about cars for more than 25 years, having defected from radio journalism to follow his passion. He has been a contributor to Autocar since 2004, and is a former editor of the Autocar website. 

Mike joined Autocar full-time in 2007, first as features editor before taking the reins at Being in charge of the video strategy at the time saw him create our long running “will it drift?” series. For which he apologies.

He specialises in adventurous drive stories, many in unlikely places. He once drove to Serbia to visit the Zastava factory, took a £1500 Mercedes W124 E-Class to Berlin to meet some of its taxi siblings and did Scotland’s North Coast 500 in a Porsche Boxster during a winter storm. He also seems to be a hypercar magnet, having driven such exotics as the Koenigsegg One:1, Lamborghini SCV12, Lotus Evija and Pagani Huayra R.

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Major Fatty 22 August 2016


It's all down to cost. If the exhaust after treatment for diesels wasn't so expensive then diesel hybrids would be more common as they would achieve higher mpg than the equivalent petrol.
fadyady 22 August 2016

Ditch the diesel

Ditching the diesel in a family size hybrid car that is likely to spend much of its time in the urban environment only makes sense given the diesel's inevitably higher NOX emissions but Kia could use similar technology in larger cars or trucks and tractors just as the article says Audi did in the Q7. Otherwise they have just introduced a petrol hybrid that at last rivals Toyota's Prius.
scrap 22 August 2016

Diesel hybrid is a terrible

Diesel hybrid is a terrible idea on cars, for reasons stated above. I can see the technology working for long distance road haulage though, with a diesel motor acting largely as a generator for an electrified drivetrain.