The deadline for new fuel norm Bharat IV, will make the vehicles in jeopardy. They must atleast run on BS-III level fuel, which is in steep scarcity in the country. The problem with the current BS-II fuel will be damage to internal parts, engine of the BS-IV upgraded vehicles. This fuel will fit in for the old cars, say experts. The new BS-IV vehicles, to be sold in those select 13 cities, will emit high sulphur content and low octane if let to run on BS-III fuel.
The problem will be with the availability of the new fuel as well as BS-III fuel. The cars having the current engine types are fit to run on BS-II or BS-III fuels. If the BS-IV compliant engines are fed with inferior fuels, then the damage will be severe for the vehicles- in acceleration, reduction in fuel efficiency and decay to the life of the engine. BS-IV vehicles will not be tuned to run on inferior fuels which possess higher amount of sulphur(50); in BS-II it is 500 and in BS-III it is 150.
The octane level will also vary- 91 in BS-IV whereas it is 88 in BS-II. The inferior fuel will affect the catalytic converter (which takes care of reducing harmful emission). The life of this converter will reduce from the tuned 80000 km. in vehicles of new technology, there is an onboard diagnostics system to alert the condition of other systems. The main hit, due to the inferior fuel like BS-II will be noble metals and catalytic converter. The practical difficulties for the car makers is that there is no instant availability of components to upgrade to BS-IV norms. The views regarding the effect of inferior fuel are expressed and echoed by technicians from Maruti and M&M.