More on the costs and benefits of clean fuels and vehicles in India


We recently held a webinar on the costs and benefits of clean vehicles and fuels in India. This was the last in a series of webinars we have conducted this year to highlight the benefits of tighter vehicle emission standards, low-sulfur fuels, and better in-use vehicle and fuel quality testing in the long term.

As usual, several questions were posed during and after the webinar. One questioner asked about the relative importance of non-tailpipe to tailpipe PM2.5 emissions, especially considering we based our lower mortality estimates on reductions in vehicle PM2.5 emissions. A study by the US Federal Highway Administration (FHWA) analyzed this issue using the US Environmental Protection Agency’s (EPA) MOBILE6.2 model. It found that tailpipe PM10 emissions were about 60% of all vehicle PM10 emissions. But for PM2.5 emissions, tailpipes accounted for close to 80%, implying less non-tailpipe PM emissions fall in the more harmful PM2.5 category. Our own analysis of emissions from Indian vehicles—which takes into account both tailpipe and non-tailpipe emissions—estimates that non-tailpipe PM2.5 emissions are slightly higher than tailpipe PM2.5 emissions for gasoline vehicles. But for diesel vehicles—which account for about 90% of all PM2.5 emissions—tailpipes make up about 90% of all PM2.5 emissions. This could change in the future if tighter emission standards are implemented. Advanced engines and aftertreatment systems will greatly reduce tailpipe PM emissions, while emissions from brake and tire wear may not go down as much. The good news is that overall PM2.5 emissions will still fall significantly.

A second question of interest related to biofuel production and use in India. Biofuels are often used to displace petroleum, which can reduce India’s dependence on foreign fuels. The downside is that biofuel production can put strains on land-use and increase greenhouse gas emissions. India has been making efforts to increase biofuel use over the last decade. It had sought 10% ethanol blending into gasoline in 2008 and set a target of 20% biofuel blending by 2017. But biofuel production has not lived up to what was originally thought possible, and India is only now starting to fully implement 5% ethanol blending into gasoline—via ethanol imports if need be. Even if India does reach its targets, its unlikely biofuels will play an important role in reducing emissions or improving air quality; while they would have some benefits, there would be other disadvantages.

Notes from this webinar series as well as related content are collected here, and we’ll continue to add to that collection of material in the coming months. And we welcome suggestions, requests for assistance, and general conversation on the important topic of clean vehicles and clean fuels for India. The more communication there is among policymakers and stakeholders, the better.