India saw a major step forward in emission standards when the country frog leapt from BS4 to BS6 emission norms. While this was huge on its own, there was another transition happening on the side with fuels — they started getting ethanol mix. Today, we stand at a 20 percent ethanol mix with fuel, and many concerns.
What fuel should you be filling for a BS4 vehicle? What if you have an early BS6 vehicle? How about the BS6 Stage 2 vehicles? Here’s your explanation for all of these questions.
Bharat Stage (BS) 4 or 6 vehicles have one major difference: the type of fuel they use, and it’s not the ethanol content. BS6 vehicles are designed to run on fuel that has a lower sulphur level, and the goal was to reduce pollutants from a vehicle’s engine.
Under BS4 norms, the permissible Nitrogen Oxide emitted from a vehicle was capped at 80mg, while the BS6 norms cap it at 60mg. This is for petrol vehicles only.
The government mandated that all vehicles sold in India since April 1, 2020 have to be BS6compliant, including twowheelers. With the decision, India completely skipped BS5 norms, which made it a huge challenge for automakers to follow, but they did manage to pull it off.
While BS4 vehicles are ethanolblend compatible, not all are. So is the case for BS6 vehicles. Only vehicles that are BS6 Stage 2compliant are capable of running on E20 petrol, or petrol mixes with 20 percent ethanol. The older BS4 vehicles can run on E5 or E10, but it is subject to the manufacturer, and they had no proper standard when they were sold.
Now, the problem with ethanol is its hygroscopic nature, meaning it attracts moisture. This can lead to tanks getting corroded (older metal tanks), and this, in turn, can harm the fuel system, especially with BS4 vehicles. BS4 vehicles feature carburettors, and when the vehicle is parked for a prolonged period of time, it can cause a sticky substance that can mess up the entire fuel system.
Also, since older vehicles were not designed to run on E20 fuel, they can cause harm to the engine in the long run. A vehicle can also see a drop in mileage, as ethanol does not have the same energy density as pure petrol. So the best option for BS4 vehicles and early BS6 vehicles is to use highoctane fuel that has no ethanol mix in it, like the XP100 or HPCL’s poWer100.
This is a subjective matter again. Early BS6 vehicles may not be fully E20 compliant, and they can also see longterm damage if the manufacturer has not specified it. They also face the same issue of ruining fuel lines and damaging the engine owing to its hygroscopic nature, especially when vehicles are parked for a few days or longer.
However, BS6 Stage 2 vehicles can run on E20 fuel, as all manufacturers were mandated to make engines compliant. They run just fine on E20 fuel, but will also face fuel line and engine damage if the vehicle sits for too many days. Manufacturers are blending the E20 fuels with other additives to mitigate this issue. While modern cars won’t really have to worry about fuel tank corrosion, the easiest way is to opt for a higher octane fuel that costs more.
