5 in 10 petrol vehicle owners with a vehicle (purchased 2022 or prior) confirm experiencing lower mileage post E20 petrol mandate in 2025; 3 in 10 confirm experiencing unusual level of vehicle wear & tear

February 27, 2026, New Delhi: Setting new standards for E20 petrol being sold across India, the government has mandated that from April 1, 2026, ethanol-blended petrol (up to 20% ethanol) must have a minimum Research Octane Number (RON) of 95. Higher octane fuel is more stable under compression and reduces the risk of engine knocking — a phenomenon that occurs when fuel burns unevenly inside the engine cylinder and can lead to long-term engine damage.

In a notification dated February 17, the Ministry of Petroleum and Natural Gas directed oil marketing companies to supply E20 petrol conforming to Bureau of Indian Standards specifications and maintaining a minimum RON of 95 across states and Union Territories.

Most vehicles manufactured between 2023 and 2025 onward have been engineered or recalibrated to run on E20 fuel. However, concerns persist for older vehicles. Ethanol has different chemical properties compared to petrol; it absorbs moisture and can degrade rubber and plastic components over time. This raises risks of corrosion, seal deterioration, and wear in fuel systems not designed for higher ethanol blends.

Since India mandated E20 petrol nationwide in 2025 (20% ethanol blended with 80% petrol), many owners of older cars and two-wheelers — particularly those built before 2022 and calibrated for E5 or E10 — have reported operational challenges. A significant proportion of petrol vehicles currently on Indian roads are not fully E20-compatible.

While policymakers’ position E20 as a key step toward lowering emissions and reducing crude oil imports, user experiences have been mixed. Ethanol has a lower energy density than petrol, which can reduce fuel efficiency. Although official estimates suggest a 1–6% drop in mileage, several independent user surveys indicate reductions of 10–20% in older vehicles.

Vehicle owners have voiced concerns on social media platforms, reporting decreased mileage, higher NVH (noise, vibration, harshness) levels, starting troubles, and in some cases moisture separation in fuel tanks. Others cite accelerated wear in fuel pumps, injectors, gaskets, seals, and fuel lines. Maintenance costs have reportedly increased due to more frequent servicing and part replacements. Some anecdotal accounts even describe reduced engine compression in motorcycles after prolonged E20 use, though such claims lack large-scale technical validation.

With E20 now the default petrol grade in most regions, access to lower-ethanol alternatives such as E0 or E5 has become limited. This leaves owners of non-compatible vehicles with fewer options and concerns about long-term durability and warranty coverage.

Automakers, however, are proactively adapting. Most models introduced from 2025 onward are fully E20-ready, incorporating ethanol-resistant materials and engine recalibration to maintain performance and efficiency.

Broader automotive trends show gradual diversification rather than a direct backlash. While there is no definitive trade data linking E20 to a sell-off of older petrol vehicles, diesel has retained a steady share in the passenger vehicle market. Meanwhile, electric vehicle (EV) sales have grown rapidly — around 70–80% year-on-year — though EVs still account for roughly 4–8% of total sales depending on the segment.

Hybrid adoption is also rising, driven by fuel costs, emissions goals, and long-term ownership economics, not solely E20 concerns.

Overall, while E20 has influenced consumer sentiment — particularly among owners of older petrol vehicles — there is no clear evidence yet of a large-scale structural shift driven exclusively by ethanol blending. The transition appears gradual, shaped by policy goals, evolving vehicle technology, and broader market dynamics.

Almost 10 months after the government mandated to supply only E20 fuel, LocalCircles has conducted a fresh survey to find out if there has been any change in the fuel efficiency or impact on petrol vehicles. The survey received over 50,000 responses from owners of petrol vehicle (2022 or prior models) and located across 301 districts of India. 69% respondents were men while 31% respondents were women. 45% of respondents were from tier 1, 29% from tier 2 and 26% respondents were from tier 3, 4 & 5 districts.

1 in 2 petrol vehicle owners with a vehicle that was purchased in 2022 or earlier say their vehicle’s fuel efficiency/mileage has reduced in the last 9 months

The survey first asked vehicle owners, “If you have a petrol vehicle that was purchased in 2022 or years prior, how much has the fuel efficiency / mileage of your vehicle(s) reduced since early 2025?” Out of 24,710 who responded to the question 25% indicated that the fuel efficiency has dipped “by over 20%”; 7% of respondents indicated a dip of “15-20%” in fuel efficiency; 13% of respondents indicated “10-15%” dip in efficiency; 7% of respondents indicated “1-2%” dip in efficiency; 27% of respondents indicated “no impact”; and 21% of respondents did not give a clear answer. To sum up, 1 in 2 petrol vehicle owners with a vehicle that was purchased in 2022 or earlier say their vehicle’s fuel efficiency/mileage has reduced in the last 9 months.

29% of owners of petrol vehicles (purchased in 2022 or prior) confirm experiencing unusual levels of wear & tear or need for repair in the last 9 months with regards to engine, fuel line, tank, carburettor, etc.

As many vehicle owners have complained on social media about more than usual wear and tear of their vehicles post usage of E20 petrol, the survey asked, “If you have a petrol vehicle that was purchased in 2022 or years prior, have you experienced unusual level of wear & tear/ need for repair since early 2025 with regards to engine, fuel line, tank, carburettor, etc.?” Out of 25,686 who responded to the question 60% stated “no, nothing unusual”; 29% of respondents however stated “yes, definitely have”; and 12% of respondents did not give a clear answer. To sum up, 29% of owners of petrol vehicles (purchased in 2022 or prior) confirm experiencing unusual levels of wear & tear, or need for repair in the last 9 months with regards to engine, fuel line, tank, carburettor, etc.

In summary, the study shows that 1 in 2 petrol vehicle owners with a vehicle that was purchased in 2022 or earlier say their vehicle’s fuel efficiency/mileage has reduced in the last 9 months. Similarly, 29% of owners of petrol vehicles (purchased in 2022 or prior) confirm experiencing unusual levels of wear & tear, or need for repair in the last 9 months with regards to engine, fuel line, tank, carburettor, etc.

Whether the new E20 standard will fully address the issues facing owners of older petrol vehicle owners remains to be seen. In the interim, there is need for policy planners to relook on the ethanol policy as fuel efficiency must be a priority along with environmental concerns as they are interlinked. Also, the fact that more than one-fourth of those surveyed have experienced more than usual wear and tear of their vehicle or need for repair shows that many vehicles will become un-road worthy sooner than 15-year life fixed by the government for petrol vehicles.

If the higher-octane ethanol blended fuel does not address the issues being faced by older petrol vehicle owners, the government needs to relook at its fuel policy to allow sale of lower ethanol mix fuel for older petrol vehicles so that it does not tax owners of such vehicles. Not all are able to switch vehicles at will as funds remain a big concern in most households in India.