Busting Fuel Additives Myth: Do They Work Or Not

I was in my teens when I got my first car. It was a white Suzuki Mehran. I took it to a Caltex fuel station and asked the attendant to fill it up. While I was standing next to petrol dispenser, a small black plastic bottle caught my eyes and I picked it up to read what it said. It was a fuel additive. I had absolutely no idea what it was. I asked the attendant about it and he said ‘it makes your car run smoother and improve mileage’. I had no clue if it will work or not, but in the love of my new pride and joy, I bought the bottle and poured it in the fuel tank myself.

I have no idea if it worked or not, and if it did, then up to what extent. But I used to tell myself that car is running better. I, of course, have no proof of that, but I was content with my decision, even though now I think differently. Now, however, I don’t feel much optimistic about fuel additives anymore. Few days ago, on one of the blog posts, we received a comment asking about the effectiveness of fuel additives and if they are recommended. In this article, we will try to explain a bit what they are and what can you expect from them. Fuel additive products is whole big industry with a lot of players in the market, so explaining all of them will not be possible, but we’ll try to give you an educated idea so you can decide for yourself if they are for you or not.

You will always find someone, a relative or a friend, who would be adamant that fuel additives work. Well, the first thing is what are fuel additives? One definition is:

“Any liquid that is added into the fuel supply of vehicles either via the filler cap or other parts of the fuel system is classed as a fuel additive.” (Fuel Duty, Business Link)

Fuel additives are compounds formulated to enhance the quality and efficiency of the fuels used in motor vehicles. So the definition is sorted. Fuel additives can be octane boosters or those that reduce the corrosion of your engine internals (corrosion inhibitors). Diesel additives often offer the benefit of functioning as an antioxidant that helps to minimize corrosion within the engine as well as antiknock agents to ease the stress on engine pistons. Then there are those that help to clean your fuel injectors and system. As I said above, fuel additives are a big business, and I am sure if you go deeper, you will more types and combinations of products with varying possible benefits. Choose wisely, if you really want to choose.

The kind we are going to discuss is the one that claims to boost your fuel’s octane ratings. The majority of additives boast to be able to increase your car’s acceleration and engine performance. Not only they claim to improve your fuel average but also rejuvenate its horsepower. However, one positive aspect, that is present in most additives, is their capability to remove dirt residue and other harmful deposits which, over the life of your vehicle can build up in your fueling system (fuel lines, filters, injectors etc).

Now comes the question whether they will make your car go vroom vroom. That is the million dollar question. Opponents claim that over-the-counter additives for fuel provide no extra benefits and in fact could damage the engines if nor used properly. Normal fuel that you get from your average fuel station is equipped with your car’s octane needs; unless you are running a racecar that needs specific kind of fuel. But if for some reason, you are stuck with fuel that would barely pass as being fuel, the additives may work to increase octane rating of the fuel as your vehicle requires. Your over the counter additives, octane boosters in this case, might help you there. Maybe in very specific conditions, where factor are stable and under control, they have positive effect. But other than that, they don’t usually work like you want them to.

But they are not at all evil, and some do have a little benefit to them. Additives can take the form of oxygenates (alcohol or ethers) and this can reduce the harmful emissions by reducing the carbon monoxide from your car exhaust. And if you are using the additives like anti-knocking agents to have a smooth running engine, maybe it’s time to get it inspect rather than using short cuts like fuel additives.

And as mentioned above, the fuel additives can be helpful in removing slime and grime from your car’s fueling system. There are three common cleaning agents used in most top selling brands, polyisobutene or PIB, Polyisobutylene amine or PIBA and Polyetheramine or PEA. Most of these are nitrogen based and act as a detergent. If a product lacks a nitrogen based additive, its cleaning ability is negligible. Which detergent and how much of it is in the formula will determine the cleaning power of your fuel additive and the treatment interval.

Basically, PIB is good, PIBA is better, and PEA is the best. The ratio of cleaning agents to other fluids in an additive will determine how well it cleans existing deposits and prevents new ones from forming. This ratio can vary considerably by brand and product and is not always reflected in the price. However, if an additive does not contain PEA or one of the other nitrogen-based detergents, it simply is not cleaning.

You cannot buy fuel efficiency in a bottle; you vehicle must be fuel efficient from the get go. And also, it is quite possible, that old school carby engines behaved differently on additives than your new fancy ECU controlled engines that take all the input from different sensors and adjust your car’s ignition and fueling setting accordingly. Mileage-boosting fuel additives claim to increase the combustion efficiency of fuel. But the automaker programs a vehicle’s computer to have optimal fuel economy with your everyday average pump fuel. Change the chemistry, and you may actually find a decline in both performance and mileage – if there is any real change at all. The additives are short term fixes to real problems that need either a mechanic’s attention, or maybe a different vehicle all together.

Some additives are detrimental to environment, and are controlled or altogether banned in some countries. Like in US, their Environmental Protection Agency (EPA) requires the registration of all fuel additives which are commercially distributed for use in highway motor vehicles in the United States, and may require testing.

So yeah, be careful when buying fuel additives. Think thoroughly whether you will reap any benefit from spending extra on additives. There is a high chance that you do not need them at all, and you are only burning your extra money with fuel that is already an efficient combustible element. If there is any positive thing about them, that their cleaning capabilities. If you and your mechanic have come to a conclusion that your fueling system needs a cleaning, or one of your system is choking or something, try a good brand injector cleaner. That might solve the issue without opening everything up. But in your everyday use, on your average vehicle, it is better to stay away from fuel additives.