High chloride and moisture contamination in E20 petrol has emerged as a growing concern for the automotive industry, with vehicle manufacturers reporting a rise in failures of fuel system and exhaust-related components. Following discussions with automobile manufacturers and oil marketing companies (OMCs), the Centre has directed OMCs to strengthen fuel quality monitoring at retail outlets, while the industry has called for tighter fuel quality standards.
- High chloride and moisture levels found in E20 fuel samples
- Ageing fuel infrastructure identified as a likely source
- Industry calls for mandatory chloride limits in BIS standards
Contamination linked to rise in component failures
According to industry findings shared with the Ministry of Petroleum and Natural Gas, automakers have reported a significant increase in the replacement of fuel injectors, fuel pumps and other parts that come into direct contact with fuel. Field investigations have identified corrosion and wear caused by excessive chloride contamination as a key contributing factor.
Industry assessments indicate that chloride contamination, when combined with moisture, can form an acidic mixture that corrodes precision components such as fuel injectors, potentially leading to both immediate and long-term damage.
Fuel samples collected from vehicle tanks have recorded chloride contamination levels of up to 500mg/kg, while samples collected from retail outlets have shown levels of up to 350mg/kg. Separate industry assessments have reported chloride levels of up to 300ppm at some fuel outlets, against a recommended limit of under 10ppm.
Moisture contamination adds to the problem
Industry assessments have also reported excessive moisture contamination in E20 petrol. Some samples recorded water content exceeding 10,000mg/kg, while separate investigations found levels of around 7,000mg/kg, against the permissible limit of 3,000mg/kg. Excess moisture can lead to phase separation, where the ethanol-water mixture settles at the bottom of the fuel tank and may be drawn into the engine during operation.
Chlorides and moisture enter the vehicle’s fuel tank via contaminated water and an unclean supply chain, made worse by ethanol's hygroscopic nature. Industry assessments point to ageing storage tanks, pipelines, fuel tankers and other fuel handling infrastructure as likely sources of contamination.
Some petrol pump operators have also raised concerns that ageing underground storage tanks, particularly during the monsoon or in coastal regions, could be more susceptible to moisture ingress, increasing the risk of phase separation in ethanol-blended fuel. The contamination issue is cropping up in certain pockets of the country, especially in the north.
The latest developments come weeks after Mercedes-Benz India also raised concerns over fuel contamination and urged tighter fuel quality checks after reporting contamination-related damage to vehicle components in some cases.
Industry seeks tighter fuel quality standards
According to report from CNBC TV18, the Society of Indian Automobile Manufacturers (SIAM) has urged the government to introduce mandatory chloride limits in BIS fuel specifications. It has proposed a chloride limit of less than 1mg/kg for commercial E20 and E85 fuels, and less than 3mg/kg for anhydrous ethanol used for blending. SIAM said it has been raising the issue with BIS for more than two years, but the proposal has not yet been implemented.
SIAM has also recommended regular audits of older fuel stations, stricter quality checks across the retail fuel network and mandatory chloride limits for diesel, where the parameter currently remains optional. The Centre has since asked OMCs to strengthen on-ground fuel quality monitoring while the root causes of contamination are investigated.
With inputs from Hormazd Sorabjee
Source: CNBC TV18, SIAM, OMCs and auto manufacturers.
Dipan Sur
Saptarshi Mondal
Suraj Viswanathan
Anurag Chaturvedi
Autocar India News Desk
