2W makers to oppose immediate real driving emission norms in BS7

The automobile industry, through the Society of Indian Automobile Manufacturers (Siam), is planning to resist the immediate introduction of real driving emissions (RDE) measurement norms for two-wheelers (2Ws) under the proposed BS7 emission regime, Business Standard has learnt. 

During internal discussions, major 2W makers have cited concerns over the weight and accuracy of equipment used to measure RDE on the road, as its heaviness itself can increase emissions. 

They also pointed to the absence of a developed and ready “RDE cycle” — the prescribed pattern of speeds, acceleration and riding conditions used for testing emissions on roads — for motorcycles and insufficient real-world data. 

RDE refers to measuring pollutants emitted by a vehicle dur­ing actual road driving instead of a controlled laboratory test.  India currently applies RDE requirements to four-wheelers weighing less than 3.5 tonnes, but there is no global precedent for RDE for two-wheelers. 

Currently, BS6 emission norms are in place in India, while BS7 norms are under discussion between the government and the auto industry. BS7 emission norms might come into force from 2027. Siam did not respond to Business Standard’s queries on this matter. 

“The industry’s position is not against RDE permanently. It would seek more time from the ministry (Ministry of Road Transport and Highways) to develop suitable measurement equipment and a reliable testing methodology before RDE becomes a regulatory requirement for 2Ws,” an executive of a major 2W maker said. 

Therefore, during internal Siam discussions, 2W makers said RDE for two-wheelers sh­o­uld be taken up in Phase-II of BS7, rather than being from the beginning. During the discussions, major 2W makers talked about the concerns raised by the Japan Automobile Manufacturers Association (JAMA) over application of the current portable emissions measurement systems (PEMS) technology to motorcycles. PEMS is equipment fitted to a vehicle to measure its emissions during actual road driving. 

One of the main concerns is the size and weight of PEMS equipment. 2W makers, during internal discussions, said that commercially available PEMS is large and heavy. This can affect the motorcycle’s stability and handling. It could result in high measurement inaccuracy when the equipment is used with small-capacity engines. 

They also cited a study by Japan Automotive Research Institute (JARI), which compared PEMS measurements with those from a laboratory analyser on five motorcycles. 

The study found that PEMS did not meet European RDE accuracy requirements for carbon monoxide (CO), total hydrocarbons (THC), nitrogen oxides (NOx) and carbon dioxide (CO2) across all five motorcycles during the World Motorcycle Test Cycle (WMTC). 

Adding 120 kg of PEMS equipment resulted in a significant increase in emissions. 

Average CO emissions increased by 26 per cent, while average NOx emissions rose 66 per cent across the five motorcycles, according to the study. 

The 2W makers also pointed to gaps in the testing methodology. An RDE cycle for two-wheelers is yet to be prepared. Executives of 2W makers said there is a need to establish “correlation and repeatability.” This means the test should accurately reflect real-world riding and produce consistent results when repeated. They pointed out that Indian two-wheelers shifted from the Indian Driving Cycle to the World Motorcycle Test Cycle (WMTC) in 2017. WMTC is alre­ady close to a real-driving cycle, which is another reason for fur­ther study before a separate RDE requirement is introduced, they added. 

Siam’s internal discussions have considered two alternatives to conventional RDE testing for motorcycles.

 

The first is a “Random Cycle Generator (RCG),” under which extensive real-world riding data would be collected and analysed to develop representative random driving cycles. These cycles could then be used for emissions assessment and validation.

 

The second option is to use a chassis dynamometer, a laboratory machine with rollers on which a motorcycle runs, while developing the test cycle using real-world driving data. This would allow actual riding patterns to be reproduced in a laboratory without requiring the motorcycle to carry heavy emissions-measuring equipment during road testing.

 

However, both alternatives face a basic challenge: Determining what constitutes representative real-world riding. Excessively aggressive or overly gentle riding patterns would need to be excluded.

 

Developing such criteria would require extensive real-world data covering different vehicle types, traffic conditions, road environments and rider behaviour, the executives added.

 

Even if regulators decide to conduct the test in a laboratory using real-world riding data, they still have to decide exactly how that laboratory test should work. For example, they have to decide whether the test should include uphill and downhill roads.

 

Siam, therefore, is planning to propose that alternative motorcycle RDE procedures be treated as a Phase-II activity under BS7. This would give manufacturers and the ministry time for data collection, methodology development and validation before regulatory implementation.

 

Key concerns

• Siam may seek Phase II implementation, rather than introducing real driving emissions (RDE) for two-wheelers from the time BS7 starts
• 2W makers have cited concerns over the weight and accuracy of equipment used to measure RDE on the road
• PEMS equipment being bulky could itself end up increasing emissions
• Siam has considered two alternatives to conventional RDE testing for motorcycles