What is the Difference between Premium petrol and Regular petrol/gasoline?

We all know that an internal combustion engine requires three important things to produce power and they are fuel, air, and combustion. Fuel plays a major role in the overall efficiency and performance of the engine, so it becomes very important that what are you filling into your tank. Right now, we get a variety of petrol or gasoline at a petrol pump. Premium fuel can be made premium by simply adding some detergents in them or by increasing the octane numbers in it. A normal commuter, who has limited knowledge about them, becomes confused as to what to choose. With a considerable price difference between them, you could very well be wasting your money by adding the premium stuff even when your vehicle does not require it. So it is better to have an understanding of the different categories of petrol. Let us learn more about premium gasoline vs regular in this article. 

“$5+ premium gas in San Francisco” by aloharakesh is licensed under CC BY-NC-ND 2.0

The basic difference

The difference between the two petrol types can be the difference in octane rating, or it could be simply the difference between the composition of additives in the base chemical structure. The octane rating is the standard rating that tells about the fuel’s ability to withstand the internal compression of the engine before it detonates. Octane rating is simply the ability to take more pressure and has no direct relation to the power output of the engine. They are used in the engine which has higher compression ratios. In India, the octane ratings differ between 87-97 octanes, depending on fuel type. On the other hand, fuel can also be made premium by additives such as cleaning agents that help keep the fuel system of a vehicle healthy. There is a lot of debate whether they are effective or not and have caused some problems in modern GDI(direct injection) engines that have tighter tolerance levels in the fuel system. 

When do you need premium fuel?

As discussed above, a petrol engine with a higher internal compression ratio will need a high octane number of fuel to prevent pre-detonation or ‘knocking’ of the fuel. The modern GDI engines or high-performance engines like the AMG lineup from Mercedes-Benz or superbikes like Hayabusa etc need higher rating octane in fuel to function properly. If forced to run on normal fuel, then the engine management of the vehicle will gradually reduce the power, and you will get a very bad efficiency and output from the engine. They do require 97 octane fuel. Other car engines are hybrid and can manage between 87 or 94 octane fuel, and you can fill them up according to the fuel availability and requirements. 

When you do not need premium fuel? 

If you have a run-of-the-mill vehicle like a Honda Activa or Maruti Swift, then you will be wasting your money if you think that by simply pouring 97 octane fuel in, you will gain a considerable amount of power. Low compression engines run just fine with regular fuel, and you won’t gain any extra horsepower by using more octane numbers. As stated above, a higher octane number will only benefit a higher compression ratio engine. As with premium fuel with additives and detergents, there are two schools of thought. Some believe that they have seen improvement after adding premium fuel with additives. But it could be just a placebo effect or their vehicles were not maintained properly, and premium fuel could have simply unclogged the fuel system. The simple thing to do is to stick to the owner’s manual and fill what the manufacturer describes the best for them. Modern cars have very tight tolerance levels, and they can throw a fit if some non-recommended additives are added, causing you additional money in repairs. So stick to regular fuel if your engine does not require it. 


So, in the end, we can say that yes, there is a considerable difference between premium gasoline vs regular. But do you need premium fuel for your vehicle? That depends on the type of engine that you have under the hood of your vehicle. If your vehicle requires a 97 octane-rated petrol then fill that in. if your vehicle has flexible fuel characteristics, then fill according to your choice. But if your vehicle can happily run on a simple 87 octane-rated petrol, then stick to it and do not waste money on premium fuel. Always remember, regular maintenance is the key to the best performance and efficiency.