The VW Group’s 1.5-litre diesel engine will be yet another casualty of the stringent BS-VI emission norms that'll come into effect by April 1, 2020. Sources within the VW Group have confirmed that EA189 diesel will not be upgraded to BS-VI standards and hence production will stop with the implementation of the new norms.

We broke the news that Fiat too will discontinue its ubiquitous 1.3 Multijet diesel for similar reasons. This reflects a growing trend of automakers abandoning small diesel engines as it is proving to be quite uneconomical to produce in BS-VI spec. The costly clean-up hardware required to meet the tougher norms could make small diesel cars 25 percent more expensive. Globally too, VW is no longer investing in small diesels and has shelved its plans to develop a new 1.4, three-cylinder diesel, derived from the group’s current EA288 engine family

However, automakers like Maruti, Hyundai, Tata and Mahindra, deeply invested in the Indian market, are looking at low cost solutions to develop small-capacity BS-VI diesels. While all BS-VI diesels require a Diesel Particulate Filter (DPF), there are various low-cost options for exhaust after treatment to lower NOx emissions to the new levels.

Most automakers will use a combination of Exhaust Gas Recirculation (EGR) and a Lean NOx Trap (LNT) to reduce NOx but, according to a VW source, this solution does not give the VW 1.5 diesel "a comfortable enough margin” to comply with the tougher norms. The source further explains, “With EGR and LNT, it is possible to make our EA189 engine BS-VI compliant, but after the diesel scandal we want to play safe and be compliant with a huge margin to factor in any deviations (in emissions) that may arise due to variances in production.” VW is particularly sensitive about the EA189 engine family, which was at the heart of the scandal.

However, it is possible for the EA189 1.5 diesel engine to comfortably meet BS-VI norms by using Selective Catalytic Reduction (SCR) which sharply reduces NOx levels, but this complex process of injecting urea into the exhaust to convert harmful NOx into harmless nitrogen and oxygen is simply too expensive for a Polo or a Vento. There’s also the added complication of fitting a urea tank, which is almost impossible to package into cars built on older (PQ25) platforms.

Hence, VW’s Polo, Ameo and Vento, along with the Skoda Rapid, will run only on petrol or some form of hybrid power beyond 2020. Even the future compact car range of both brands won’t have have a diesel option.

The VW Group’s diesel play in India beyond 2020 will be centred around the 2.0-litre EA288 diesel that powers a wide range of cars from the Audi, VW and Skoda brands. There are plans to localise the EA288 engine to bring down costs but this has been put on hold. Due to the drop in sales of models that use the EA288, volumes aren’t sufficient to make localisation of the engine viable.

With no mainstream diesel engine alternative in the future, the VW Group is likely to expand and upgrade its petrol engine offerings for the Indian market.