66% of pre-2023 petrol vehicle owners report over 10% mileage drop: Survey

More than 6 in 10 owners of petrol vehicles purchased before 2023 say their vehicle's fuel mileage has dropped by over 10 per cent since early 2025, according to a new survey by LocalCircles. The findings come just over a year after India completed the nationwide rollout of E20 petrol, which contains 20 per cent ethanol blended with petrol.

 

The survey found that 66 per cent of pre-2023 vehicle owners reported a fuel efficiency decline of more than 10 per cent, up sharply from 45 per cent recorded in a similar survey conducted in May 2026. The rise suggests that concerns around mileage loss in older vehicles may be increasing with continued use of E20 fuel.

 

The survey received more than 44,000 responses from owners of petrol vehicles manufactured before 2023 across 305 districts. Of the respondents, 67 per cent were men and 33 per cent were women. Around 43 per cent were from Tier-I districts, 29 per cent from Tier-II districts and 28 per cent from Tier-III, Tier-IV and Tier-IV districts.

 

Sharp rise in mileage complaints

 

The survey received responses from 22,100 owners of petrol vehicles bought in 2022 or earlier. Among them, 23 per cent said mileage had fallen by more than 20 per cent, another 23 per cent reported a decline of 15-20 per cent, while 20 per cent reported a drop of 10-15 per cent. Only 13 per cent said they had seen no impact on fuel efficiency.

 

Compared with May 2026, the share of respondents reporting a mileage decline of more than 10 per cent increased by 21 percentage points within a month, representing a 47 per cent jump.

 

Ethanol contains less energy per litre than petrol, which can result in lower fuel economy. Older vehicles designed for lower ethanol blends such as E5 or E10 may not be able to adjust as effectively to E20 fuel as newer E20-compatible models, the survey stated. 

 

More owners reporting wear and tear

 

Around 55 per cent of owners of pre-2023 petrol vehicles said they had experienced an unusual increase in wear and tear or a greater need for repairs since early 2025. This is nearly double the 29 per cent reported in the May 2026 survey.

 

The findings are based on responses from 22,668 vehicle owners. Of these, 24 per cent reported a major increase in wear and tear, 21 per cent reported a moderate increase and 10% reported a slight increase. About 38 per cent said they had not noticed anything unusual.

 

The percentage of respondents reporting higher wear and tear rose by 26 percentage points between May and June, marking a 90 per cent increase within a month.

 

The survey findings come amid ongoing debate over the impact of higher ethanol blends on older vehicles. The government has stated that the ethanol blending programme is scientifically validated and has said it has not received reports of widespread engine failures linked to E20 fuel.