With less than nine months to go for the rollout of BS VI emission norms in the country, auto major Mahindra & Mahindra has announced it is ready with its portfolio of eight diesel and eight petrol engines that would comply with the most stringent regulations. Over 700 employees, together with suppliers and consultants worked tirelessly for the last three and half years to realise, what initially looked impossible to achieve. Mahindra gave us the inside story in a recent event to demystify BS VI.
Dr Pawan Goenka, Managing Director, Mahindra & Mahindra, equated the BS VI emission rollout challenge to that of the Y2K scenario close to two decades back. The IT industry was expected to come to a standstill then, but nothing like that happened. Similarly, the government’s decision to bypass one emission stage – India is moving to BS VI emission norms straight from BS IV norms, bypassing BS V norms – was fraught with nervousness among industry players.
Goenka agreed the last three and half years have probably been the most challenging for any product development and sourcing organisation in the Indian auto industry. However, as things stand today, Mahindra – as also the entire industry – seem to have pulled rabbits out of their hats to ensure the transition has been smooth and easy.
The company said it has invested over Rs 1,000 cr in developing the new range of petrol and diesel engine platforms. Eight diesel engines across 16 vehicle platforms, and eight petrol engines (also compliant to CNG) for eight vehicles platforms were worked upon. In the process, 1,482 new diesel parts and 543 new petrol parts were developed, leading to the filing of 30-plus patents. The company said 95 % of the BS VI related work was done in-house, with a localisation level of 99 %.
The entire BS VI programme was supported by a total of 125 vendors and 32 technology providers, including the likes of Continental, ZF, Mahle, Magneti Marelli, Valeo, Bharat Forge and Federal Mogul. The company also worked with consultants such as Bosch, AVL and Delphi. “It’s a story as much of technology, planning and programme management as much it is of determination of 700 people, along with our suppliers,” Goenka said.
When work began in 2016, the company was faced with two big challenges. The company had to ensure it met the time targets, but with competitive cost on the diesel portfolio. Secondly, the company had to develop an entirely new portfolio of petrol engines that are globally competitive. It must be noted that Mahindra had no petrol engine at that point in time, which meant it had an opportunity to develop and launch the latest generation of petrol engines. It did. The company now has petrol engines in two of its existing products, including the new XUV300. The fact that petrol engines account for 25 % of XUV300’s sales is a healthy indicator of the engine’s acceptance. Moreover, the company also has a stamp of approval from both Ford and SsangYong, who have decided to use Mahindra’s new petrol engines in their vehicles.
For now, Goenka said the company is ready and see no technical risk in launching BS VI vehicles in the market starting April 1, 2020. In fact, M&M will be ready with BS VI petrol and diesel vehicles by end of Q2FY20. Around the same time, the company would probably be ready to launch its BS VI-compliant petrol vehicles, because it doesn’t require BS VI ready fuel. Launching diesels would, however, depend on the availability of BS VI fuel across India, which Goenka expects to be available by end-December or early-January.
UNDERSTANDING TECHNOLOGY CHANGES
In the movement towards BS VI emissions for diesel engines, the company was faced with the challenge of reducing NOx by 68 % and soot (PM) by 82 %, while in petrol engines, CO and HC were to be cut down by 20 % and 8.5 % respectively. To ensure these targets were met, engineers had to work on major technology migration at both the engine and exhaust levels (aftertreatment).
Pankaj Sonalkar, Chief of Powertrain Engineering, M&M, said 30 % of the changes were to come from the engines, while 70 % were to be made to aftertreatment. Some major additions to the engines include components such as 2nd-generation plunger pump, electric EGR + Gen 2 cooler, gen 6+ electrically actuated turbocharger, intake throttle and the latest generation engine management system (EMS).
On the aftertreatment side, apart from the Diesel Particulate Filter (DPF) and Lean NOx Trap (LNT), differential pressure sensors, NOx sensor, Lambda sensor and supply & dosing modules were a few notable additions. The DPF absorbs the soot (PM) and doesn’t allow it to go out. For the reduction of NOx, two technologies were used – the NOx Storage Catalyst (NSC) or LNT, and the Selective Catalytic Reduction (SCR). In the LNT, NOx is stored in the catalyst and once it’s full, it is regenerated through a rich fuel pulse in the engine. This technology is mainly used for vehicles with low power density. SCR allows NOx conversion by ammonia in catalyst through Urea dosing. Of the two, SCR is more complex and expensive, but is also more efficient. SCR is used for high power density vehicles.
Although proven in Europe, technologies such as DPF, SCR and LNT becomes sub-optimal in the Indian context – across wide geographical conditions, in congested city traffic, and because of unique driver behaviour or fuel adulteration – and, hence needs India-specific development, said Sonalkar. Among other innovations, the EMS now has 18 sensors, and the control structure connects various functions including engine, aftertreatment, diagnostics and vehicle networking.
The engineering team at Mahindra Research Valley (MRV) looked at this as an opportunity to reclaim the glory of diesel engines. The team looked at every frictional part – rotating or moving – and worked on reducing friction. The turbocharger, for instance, was given new compressor and turbine wheels, and the vane height was also increased. Likewise, the fuel injection system improved hydraulic efficiency by 92 % and the Exhaust Gas Recirculation (EGR) module increased efficiency by 85 %. All-in-all, this resulted in a massive 30 % friction reduction out of the system and a 3 % improvement in fuel efficiency, explained Sonalkar.
Obviously, every technology upgrade would result in added cost. But unlike believed earlier, it wouldn’t result in any significant hike. For the Mahindra team, the cost target was Rs 0.6 X of a European model (Rs X), and the team managed to achieve Rs 0.5 X. This was achieved through a high level of system design optimisation, optimal technology selection, on-boarding of vendors early into the process, supplier collaborations and high localisation content.
Mahindra engineers clearly have done a fabulous job of getting its entire range of engines BS VI ready. Goenka, however, knows the biggest challenge is not about being product ready, but managing the transition flawlessly. In a short span of two to three months, the company will need to ramp up and ramp down the entire volume of its automotive business. He recognises that is a humongous challenge for not just M&M’s plants, but also its suppliers.
Secondly, estimating demand for BS VI wouldn’t be easy either. Even before the rollout, it will require proper planning and inventory management on M&M’s part to ensure minimum inventory of BS IV vehicles as on March 31, 2020. Small BS VI diesel engines are likely to become commercially unviable. M&M, in fact, has announced discontinuation of its 1.2 l diesel engine on the KUV100.
TEXT: Deepangshu Dev Sarmah