Ashok Leyland Managing Director and CEO Shenu Agarwal on Thursday expressed scepticism about the use of retrofit emission devices on older trucks, questioning whether such solutions can deliver sustained BS6-equivalent emission performance and durability over the long term.
His comments come as the government explores retrofit emission-control devices as another way of reducing pollution from India's large population of older trucks and buses, alongside vehicle replacement and scrappage.
“In our experience it doesn't work that well,” Agarwal said when asked about retrofitting older vehicles. “That is not to say that the possibility is not there.”
Agarwal, who has also taken over as President of the Society of Indian Automobile Manufacturers (SIAM), said similar conversions have been attempted in the past across different fuels, while companies are also exploring conversion of diesel vehicles to electric.
The problem, he said, is convincing fleet operators that a modified vehicle will perform consistently over its remaining life.
“They would like a more engineered product rather than something which is coming from retrofitting,” Agarwal said.
Customers may accept a demonstration or a short-term trial, but questions remain over whether the system will maintain its performance for two years, five years or longer, he said.
Questions Economics of BS4-to-BS6 Conversion
Agarwal was sceptical about claims that an older BS4 vehicle could be brought to BS6-equivalent emission levels at a relatively low cost.
India's shift from BS4 directly to BS6 in April 2020 required significant changes to diesel powertrains and exhaust after-treatment systems. For diesel engines, the transition involved technologies such as diesel particulate filters and systems for reducing nitrogen oxide emissions.
“Going from BS4 to BS6, you know what was the cost increase, and then converting a BS4 to BS6 at such a low cost which is fraction of the original cost is difficult,” Agarwal said.
Government Clears AIS-228 Retrofit Standard
Agarwal's comments follow the Road Transport Ministry's clearance of AIS-228, a technical standard for fitting retrofit emission-control devices to older heavy commercial vehicles.
Road Transport and Highways Minister Nitin Gadkari said at the SIAM convention that the system, based on technology developed at IIT Delhi, could cut particulate matter emissions from pre-BS6 heavy vehicles by up to 90% and NOx emissions by up to 60%. Gadkari said a retrofitted BS4 vehicle could achieve emissions comparable with a BS6 vehicle.
The retrofit option could give operators of ageing trucks and buses another route to meet tighter pollution requirements instead of immediately scrapping or replacing their vehicles.
This comes alongside the government's Parivartan programme in Delhi-NCR, which seeks to accelerate replacement of older trucks and buses with BS6 or electric vehicles. The scheme covers BS4 and older commercial vehicles and combines central support, state tax concessions and incentives from other stakeholders.
Agarwal Expects Rigorous Testing
Agarwal said a retrofit technology that becomes widely used would have to prove itself through extensive testing.
“If it becomes more prominent it will be going through a lot of tough testing,” he said.
His concern is not simply whether a retrofit device can reduce emissions during an initial test, but whether that performance can be maintained consistently over the operating life of a commercial vehicle.
That is particularly important for trucks, which typically cover longer distances and operate under widely varying loads and conditions.
Scrappage Remains a Preferred Trigger for Replacement
Agarwal separately backed vehicle scrappage and the Parivartan programme as ways to accelerate replacement of older commercial vehicles.
He said fleet operators increasingly recognise that a new BS6 truck can offer a better overall business proposition than continuing to operate older BS2 or BS3 vehicles.
“The fundamental equation is in favor of upgrading or scrapping the old one and upgrading to a new one,” he said.
Scrappage incentives can provide the additional trigger needed to persuade operators to make that investment sooner, he added.
Agarwal said such support should eventually extend beyond Delhi, given the large population of ageing commercial vehicles across India.
“Right now it is restricted to Delhi because Delhi needs it most, but actually it is needed in the entire country,” he said.
The emerging debate therefore presents operators with different routes to cleaning up the existing fleet: retrofit older vehicles with emission-control systems, scrap and replace them with BS6 vehicles, or move directly to newer powertrains such as electric where the economics allow.
For Agarwal, the key test for retrofits will be whether they can prove the same durability, emissions performance and engineering reliability that customers expect from a vehicle designed for the newer standard.