Emissions and fuel consumption reduction potential from two- and three-wheelers in India

Published: 2012.09.10

Narayan V. Iyer

Motorcycle sales in India have been growing at double-digit rates, and recently passed the million-vehicle-per-month mark. With annual sales five times those of passenger cars, motorcycles dominate the on-road passenger vehicle fleet. Meanwhile, three-wheelers, which play a critical role in providing point-to-point as well as feeder service in India's urban and semi-urban areas, are on a path to surpass half a million annual sales. Given the importance of these vehicles to personal mobility in India, reducing their emissions and fuel consumption must be a priority for health, environmental, and energy policy.

In 2007, the ICCT published an initial assessment of technologies to control air pollution from motorcycles, followed shortly after by a more comprehensive review of opportunities to reduce emissions and fuel use. These reports set the stage for a detailed country-specific assessment of technology and policy opportunities for realizing on-road emission reduction from two- and three-wheelers.

This report offers a broad overview of engine technology changes and after-treatment systems being employed by Indian manufacturers of two- and three-wheel vehicles to meet the emission standards (Bharat Stage III) in place for a range of fuels, including petrol, diesel, CNG, and LPG, followed by an assessment of the technical options available to reduce emissions to meet the proposed Euro 4/5/6 equivalent limit values in the respective years of their likely adoption and implementation in India.

It also includes a review of the technical options that may be available over the coming decade to reduce fuel consumption of two- and three-wheelers, such as improved engines and other subsystems and control-system optimization, and an estimation of achievable fuel consumption reductions.

The report also examines ways to address the important and hitherto neglected areas of durability requirements, cold-start emissions, evaporative emissions, and on-board diagnostic systems, estimating the cost impact of various measures and summarizing the likely challenges to their introduction and effective implementation. Finally, it offers policy recommendations for improving in-use vehicle compliance testing and fuel and lubricant quality in pursuit of further reductions in emissions and fuel consumption from two- and three-wheeled vehicles.