What Is E20 Petrol, and Why Does Your Spark Plug Care?
If you've filled up at an Indian petrol pump lately, you've probably used E20 fuel: petrol blended with 20% ethanol. It's part of India's push to cut crude oil imports and lower emissions. Most drivers ask about mileage. Fewer ask about the small part that starts every combustion cycle: the spark plug. What changes with E20? Ethanol behaves differently from pure petrol: Lower energy content. Ethanol carries less energy per litre, so the engine burns slightly more fuel for the same output. Higher octane. Ethanol resists knocking better, which suits modern engines. Cooler combustion. Ethanol absorbs more heat as it vaporises, so combustion temperatures shift slightly. Attracts moisture. Ethanol is hygroscopic, so it can pull in water vapour over time. Why the spark plug matters The plug sits inside the combustion chamber and works in the middle of these changes. It has to fire reliably every time and keep its electrodes and metal parts intact under conditions that can...