Defer rollout: Mahindra to government on more accurate emissions test

In its response to the draft notification, Mahindra & Mahindra, in a letter dated May 26, urged the Ministry that a “standalone migration to WLTP be avoided” and its implementation be deferred. The automaker also suggested that the government wait until the upcoming Corporate Average Fuel Efficiency (CAFE) phase 3 norms — currently under discussion — clarify their position on adopting WLTP.

While both CAFE norms and BS VI rules currently rely on the Modified Indian Driving Cycle (MIDC) for testing, they serve different purposes: CAFE focuses on fuel efficiency and CO2 emissions, whereas BS VI covers a broader range of emissions, including particulate matter and NOx, which are key pollutants. Although CAFE 3 norms have not yet been notified, the Bureau of Energy Efficiency (BEE), the nodal agency framing them, proposed in June 2024 a shift from MIDC to WLTP starting March 31, 2027.
“Migrating to WLTP brings the emission and CO2 measurement closer to real world driving conditions. However, the emission worthiness of vehicles in Real Driving conditions have already been captured through Implementation of RDE (Real Driving Emissions) boundary conditions and its limits as part of Bharat Stage 6.2,” Mahindra said in its letter to the Ministry.

The government is examining the merits of the automaker’s claims, an official aware of the exercise said. Auto industry experts said that given Mahindra has a high diesel mix in its portfolio, it could pose a challenge for the company to comply with stricter norms since that would need after-treatment technologies to reduce emission of pollutants. Diesel engines account for more than 70 per cent of Mahindra’s SUV sales. They said that Mahindra’s pitch is to essentially delay the implementation of the third phase of the BS VI norms, given that the manufacturer has the highest exposure to diesel engines and could face the most amount of compliance burden when the WLTP norms are officially implemented.

In response to a query, a Mahindra spokesperson said, “We wish to not comment on the story.” The Ministry did not respond to a request for comment.

BS VI phase two rules, which have been in place since April 2023, introduced the RDE test, which, unlike MIDC or WLTP, measures on-road emissions. The purpose of WLTP is to calculate a more accurate conformity factor vis-a-vis the RDE test. In other words, it aims to narrow down the convergence between laboratory and on-road emissions.

BS VI norms were introduced in 2020, followed by the second phase with the introduction of the RDE test in 2023. From 2027, India is proposing to introduce the WLTP test cycle as part of the third phase of BS VI norms.

Experts said that Mahindra’s argument to seek a delay of WLTP norms hinges on the fact that under BS VI phase 2, real world emissions are already being captured. However, they also said that phase 2 has a much more relaxed RDE, with a conformity factor of 1.43, whereas under phase 3, the planned RDE has a conformity factor of 1. They said both CAFE and BS 6 phase 3 have been known for a long time to kick in from 2027, and many manufacturers have prepared for it.

In its letter to the MoRTH, Mahindra said it expected that during migration to WLTP, there would be clarity on CAFE III norms as well, with an adequate development time to ensure compliance. “This coherence is presently not established,” Mahindra said, adding: “…a standalone migration to WLTP be avoided, and its implementation be clubbed at a later point after clear definition of CAFE III on WLTP”.