Adding it up

Not too long ago we skimmed over the topic of additives , telling you that they could help make your car a better machine. I’m going to expand on that today. First off, why the need for additives? The answer is simple: your car is built to a cost. As such, the components aren’t the best they can be. Of course, there’s no need to go out and get exotic components that cost more than the car originally did, but there are a few things you can do to improve on what you’ve already got. The easiest of these things is additives.


Broadly speaking, additives are things you can add to existing fluids to make them better. One such additive is fuel additive. Injector cleaner (or carburettor cleaner, if you’re using  a really old car) is useful because it prevents injectors from gumming up. See, the injector is nothing but a nozzle that turns the fuel into a fine spray just before it enters the combustion chamber, or cylinder. Think of a pichkari that you use at Holi, or the kind of spray that exits the hose at your friendly neighbourhood car pressure-washing centre.

Carburettors also perform the same operation as fuel injectors, and therefore have to let the fuel go through tiny holes that can get clogged if the fuel is bad, or the car hasn’t been used for a very long time, letting the fuel evaporate and leave residue behind.  Additives are also present in branded fuels like Speed or Power, and they claim to do the same thing: keep your fuel delivery system and engine free from blockages and carbon deposits, which will reduce the engine’s efficiency, both in terms of power and fuel efficiency.


To explain what octane booster does, we’ll have to backpedal to what engine compression is. When the fuel and air are sucked into the cylinder and squeezed, it is compressed to a fraction of its original size. Since it is a gas, we won’t say ‘size’, we’ll call it ‘volume’ – as in ‘cc’ or ‘litres’. If the volume is compressed to a tenth of the original, the compression ratio is 10:1. The more the compression ratio, the more efficient your engine will be – but then, the more sensitive it will be to bad fuel. That’s why most of our petrol engines do not have high compression ratios.

However, with increasing demands from everyone involved, they have no choice but to increase the compression ratio and this presents a unique problem to the petrol engine, which needs the fuel/air mixture to be ignited with the spark – that of the fuel exploding by itself, much that diesel engines do. This is extremely bad for the engine and today’s car computers compensate for this ‘knocking’ or ‘pinging’ automatically. However, this still leads to increased wear and tear on engine components and reduced efficiency.  

What you can do if you have a high compression engine (second generation Honda City owners, Skoda Octavia petrol owners and all premium German petrol car owners, we’re talking to you) is add octane booster to your fuel to help your engine. The bottle you see in the image is a 350-odd ml bottle, but it will suffice for a tankful of gas. To the regular Joe like you and me, it won’t offer more performance, but it will certainly improve low-rev drivability of a high-compression engine. 

Adding it up

Engine oil additives simply take the job of engine oil and carry it a step further. Engine oil forms a slick surface between moving parts so that they can move freely; what engine oil additive does is make that layer slightly thicker so that the lubrication is even more. This makes for a decrease in engine vibrations, and in some cases, quietens it down considerably as well. If the engine is an inherently quiet, vibe-free unit then you probably won’t find much difference after the addition. There are two bottles in the image because STP makes different compounds for diesel and petrol engines – do pay attention to what you’re purchasing!

I know the image looks like an advertisement for STP products, but there is a lot of choice available in the market, even in India. Abro, Bardahl and Wurth are a few manufacturers that produce additives in India and are therefore a lot more inexpensive compared to the imported-from-the-USA STP products. 

Some of the products we’ve talked about today have an inarguable benefit to them. Octane booster, for example, will always be a good addition to a petrol Audi because the company recommends 95RON fuel. That is not to say that the vehicles cannot run on regular unleaded or branded fuels, but the only fuel we can think of that have them performing the way they should is the 97RON Speed 97. Shell’s Super Premium is rated at 93RON, which is near enough to the recommend octane rating. However, both these fuels are usually found in select areas in the heart of big cities. Regular fuel is rated at 91RON.

As always, there are positives and negatives to everything. What I’ve put down here are lessons and observations from using different products and listening to feedback from different people, from ordinary people to those whose life revolves around cars. An overwhelming majority found a difference when additives were used – you can blame it on our bad fuel quality standards, or lackadaisical attitude to preventive maintenance – but your manufacturer might not recommend you to use them. Please go through your owner’s manual or check with your service centre to find out if using additives will void your warranty before trying them out.