New Delhi, Aug. 21 -- Worried that ethanol-blended E20 petrol could hurt vehicle mileage and engine life, consumers are increasingly trading up to premium, high-octane petrol, driving its share of sales to 12-15% from about 4% in March, according to petrol pump dealers and industry executives.

The shift is notable because premium petrol is also blended with 20% ethanol. Consumers are nevertheless paying Rs.110-115 a litre for higher-octane variants such as Indian Oil Corp.'s XP95, Bharat Petroleum Corp.'s SPEED and Hindustan Petroleum Corp.'s poWer95, commonly known as "branded petrol", compared with about Rs.102 for regular petrol, in the belief that their higher octane rating and additive packages can mitigate some of the problems they...