What's your octane?

In the recent past, India has seen a rush in high octane quality petrol with premium prices and aggressive marketing by oil companies. Brands such as Speed, Power, and Xtra Premium are household names today. Two days back, a friend of mine, Peter, asked me which petrol am I using for my bike and car. When I said Speed, he asked me to check up with the mechanics to make sure it's okay to run on octane.... So, I did a little bit of research myself to understand what octane fuels are all about... now here's a run down what I found.

Octane levels:

Generally, engines with compression ratios of 9:3:1 or less can safely operate with regular unleaded 87 octane fuel. However, engines with higher compression ratios will require higher octane fuels.

Theoretically, each engine (even of the same make) will have a specific ideal fuel octane number right down to the decimal value. In the real world, however, engines of a particular make will all work perfectly in a given octane number range and it is advisable to match this manufacturer-recommended fuel octane number for your car.

Deposit formation

When one buys a new vehicle, its fuel injectors, intake valves and combustion chamber are completely free of deposits. With time, deposits accumulate on these parts, affecting the engine's performance. Deposits on the fuel injectors results in poor ignition, rough idling, reduced acceleration and higher emissions.

Now, high octane petrols not only removes the existing deposits in your engine but also prevents the formation of new ones.