What is octane rating? What does Power, Speed, XP95, Shell V-Power mean? Does it have a benefit? What the hell is E20, ethanol? What is Turbojet diesel? Confused? I can understand. Let’s clear that confusion today.
Let us understand how your standard petrol engine works. It produces power by compressing a mixture of air and petrol to ignite it and create an explosion. The piston compresses the air-fuel mixture to high pressures which ensures that the mixture ignites and explodes to produce power. Same applies for diesel. Now, what is octane rating? Octane rating, a number that applies to petrol, is the ability of fuel to withstand compression in an internal combustion engine. It is a measure of fuel stability and it’s ability to resist “engine-knocking”, a phenomenon that occurs when fuel is prematurely ignited in the engine’s cylinder, which can damage the engine. This is primarily because fuels contain an oxygenate that prevents knock by adding oxygen to the fuel. The oxygenate is commonly referred to as octane. As I mentioned previously, fuel needs air (primarily oxygen) to burn. So, the added octane helps in burning the fuel more cleanly. Sounds complicated and counterintuitive, right? To make this easy, the higher the octane rating, the more you need to compress the air-fuel mixture for it to burn, and the harder it becomes for the engine to knock. But why is this so counterintuitive? To prevent premature combustion of the fuel, which causes engine knocking. To clear the confusion, the user manual of your car or motorcycle will tell you what octane rating fuel to put in your vehicle. The standard fuel is 91 Octane. Most, if not all vehicles, can take 91 Octane, and it is recommended in most. However, if you have a car with a turbocharged petrol engine (they have higher compression ratios), or a superbike, or any petrol car with a high compression ratio, then you can refer the user manual and go for higher octane ratings, like 95 Octane. The logic being that since higher octane rating means more compression is required to combust the air-fuel mixture, engines with higher compression ratio will perform slightly smoother, better, and will be more fuel-efficient, with high octane fuel. In your regular 91 Octane engine car, (e.g. Alto, i20) you might not notice much of a difference, just the car will feel a bit smoother and will be a bit more fuel-efficient, if you put higher octane fuel in it. In cars with naturally-aspirated engines, it won’t make much of a difference. Now, when it comes to all the premium fuels in India, a bit more expensive than regular petrol, there are two types. One type is the regular 91 Octane fuel but with detergents and additives to clean your engine and fuel lines of wear and deposits. Examples are Speed, Power and Shell V-Power. Going through two or three tanks might help clean the engine, but if it’s worth the extra cost, it’s up to you. Minor bump in fuel efficiency and smoothness, but not necessary that it will be big, depends from vehicle to vehicle. The other type is where the Octane rating is actually higher, for example XP95, which is 95 Octane, and Speed97, which is 97 Octane. In the end, follow the recommended Octane rating. There is no point in pouring 99 Octane in a 91 Octane car. So, let’s move to Ethanol, since Octane is cleared. The Government is hyped up and people are talking a lot about Ethanol. The Government of India wants it to be regular as fast as possible, but why? What is Ethanol? Ethanol, is another type of fuel that can power an internal combustion engine. If you look at every type of petrol or diesel, or any type of fuel that has powered the internal combustion engine in it’s history, it has always been a type of alcohol. Ethanol, is also a type of alcohol. But why is it being applied so quickly? It is because it can be extracted from natural, renewable energy sources like sugarcane, corn and sugar beet. So, it is actually good for the environment. And that is the need of the hour, if I’m being honest. So, what the world is doing right now is running a mix of ethanol and petrol in existing petrol-engined vehicles. The country which is really forward in Ethanol usage is Brazil. So, you might have read E10, or E20 in your new vehicle. What does it mean? It means ethanol mix petrol. So, E10 means petrol with 10 percent ethanol. Same applies for E20, E85, or E100, etc. So, what’s the catch with Ethanol? First off, the fuel efficiency drops because it is not as energy efficient or energy dense as petrol. Second, you have to be careful because if your car isn’t modified for it, ethanol can corrode fuel lines and damage your engine. So, as a consumer, just look at the user manual, or at your fuel lid or tank, or ask at the dealership. If E10, or E20 is written then you will know that it is compatible. Now, diesel. You might see a “Turbojet” diesel at HP petrol pumps and it would be slightly expensive. Now, what does that mean? Nothing but just that it has additives and chemicals that help in cleaning deposits, a common problem in high-mileage diesel engines. But you will see the effect only after going through a few tanks. I personally think it’s not entirely necessary, and in modern diesels it won’t make much of a difference. If you have an old diesel, then please be careful and I suggest that you put regular diesel in it. Do your research, look at the user manual, and ask around if it is actually necessary for your car or not. However, Xtra Green is one exception that has a higher cetane value (basically octane for petrol is same as cetane for diesel) than regular diesel. It can give slightly more range than modern diesel but it’s just a slight difference, not a big one. In the end, do your research, and choose wisely.
