Volkswagen is in the midst of developing its own 48 volt mild hybrid powertrain for its cars, which is set to make its debut on a Golf-sized vehicle, according to Automotive News. The publication stated that the system could see the light of day on the T-Roc B-segment crossover, which is expected to be unveiled later this year, slotting under the larger Tiguan.

Wolfsburg’s head of development Frank Welsch said that once the technology is ready, it can be quickly rolled out across the model range. “Once we have it in an MQB-based model it’s more or less plug and play,” he said. “We can put it on other models because we have a modular platform.”

Asked about whether the Golf itself would be the first to come with the 48-volt mild hybrid system, Welsch said, “When I do development of these technologies it is not important which car gets it first. We have to have the technology ready and then we decide which car will get it first and in which market. We are in the middle of developing this, but it will definitely come.”

More and more automakers are turning to these mild hybrid systems to reduce emissions, due to a backlash on diesel vehicles that produce harmful nitrogen oxides (NOx). Mercedes-Benz will be introducing its own system on the facelifted S-Class, as will Volkswagen’s subsidiary Audi on the new A8.

Ironically, this pushback was largely instigated by VW itself, which admitted in September 2015 that it used defeat devices to cheat emissions testing, resulting in cars that produced NOx in levels that far exceeded limits in several countries. The greater Volkswagen Group has had to recall more than 11 million vehicles worldwide to rectify the issue.

Tougher emissions regulations enacted in the wake of the scandal mean that selective catalytic reduction (SCR) is required for diesel vehicles to pass them. The 1.6 litre oil burners introduced on the new Polo feature SCR, which is expected to cost an additional €200 (RM980) to the cost of each vehicle, according to an estimate by International Council on Clean Transportation senior researcher Vincente Franco.

Welsch told Autocar earlier in the year that a diesel engine “is 25% of the car itself,” adding that after-treatment systems such as SCR throw in another “€600 to €800 (RM2,900 to RM3,900) in material costs.” Automotive News says that this is particularly costly for a powertrain option that is expected to make up as much as 15% of the Polo’s global sales.

The publication stated that the new engine was supposed to be part of Volkswagen’s small-displacement engine push, but the high cost of developing an effective after-treatment system is causing it to rethink its strategy and move instead into mild hybrid technology. A report by Car and Driver said that the larger EA288 2.0 litre turbodiesel will continue to be developed, but nothing smaller.

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