The subsidy announced by the state government will hardly help in getting autorickshaws to switch to the liquefied petroleum gas (LPG) unless the sale of adulterated petrol is stopped, experts feel.

“Most autos run on katatel, or petrol mixed with naphtha, kerosene and solvents. The adulterated fuel earns them much more profit than LPG ever will. If this factor is not taken into account, the LPG drive will draw a blank,” said emission expert S.M. Ghosh.

The state government has made it mandatory for all autos in greater Calcutta to switch to the green fuel. A fund has been created, from which each auto will be given Rs 4,000 to encourage the conversion.

Ghosh has prepared a report comparing the economics of using adulterated fuel and LPG to drive home the point that subsidy alone would not be enough to fetch the results. The report has been submitted to the government.

The report states that katatel sells at Rs 32 a litre, against LPG, which is priced at Rs 27. If an auto requires five litres of fuel a day, the cost for katatel would come to Rs 160 and that for LPG Rs 135.

The driver of an LPG auto, on the other hand, has to give the owner Rs 180 a day for the kit, against Rs 120 that the driver of a katatel auto is required to give. At the end of the day, katatel proves cheaper than LPG by Rs 35. The monthly saving will be around Rs 1,000.

This has prompted auto drivers to gang up against the switch, said an auto owner.

“Unless the sale of adulterated fuel is stopped, auto operators will never feel encouraged to adopt LPG, subsidy or no subsidy,” said Ghosh.

“Many autos run on katatel, but it is the duty of police to stop the illegal practice,” said Citu leader Anadi Shaw.

Trinamul leader Sovondeb Chattopadhyay suggested that the government increase the subsidy.