If you’ve been avoiding “off-brand” petrol stations because you’re afraid of what their cheaper product might do to your car, maybe it’s time to re-assess your thinking.
In Australia, most petrol stations offer a range of fuel types (E10, 91, 95, 98). These labels are what’s called the Research Octane Number (RON). The RON is really just a fancy way of indicating how well the fuel will resist burning too early inside your engine. This pre-burn can destroy engine internals, cause misfires, idling, clogging up of fuel injectors and be less fuel efficient. The higher the number the better the fuel may perform. Retailers must meet a minimum standard of petrol quality (RON 91) set out in the National Fuel Quality Standards.
What a lot of people don’t realise is that the petrol that you buy at the cheaper stations and the petrol that you buy at the premium stations, actually comes from the same refinery. In these refineries they mix additives (government mandated) in order to clean a car’s engine and reduce emissions. Then, when the fuel is distributed to the different petrol companies, they put their own additive packages in to their fuel. The key difference between the cheaper and the major petrol stations in Australia is that the major brands put their own “secret” combination of additives in their fuel which they say provides an even better level of cleaning, performance and protection for your engine.
Twenty years, only premium fuels had these extra additives in it. Back then, it was beneficial to occasionally buy a tank of higher quality fuel to “clean” the engine. This may be where some of these cheap fuel misconceptions may have sprouted from.
Fuels sold at the discount stations will not hurt your car. In fact, most drivers, won’t notice any drop in performance between different brands of fuel between the major chains and the discount stores. A blind study in the US (The Auto Club) on three samples of fuel from major and independent stations tested emissions, fuel economy and performance and they could not tell the difference in brand. This was confirmed in a study by engineers at Toyota who studied the effects of different brands of fuel on their engines. After 10,000 miles of running them on different brands of fuel to see if there is a difference, they were tested, and the engineers could not determine the difference in fuel brand usage.
What is true though is that a higher-octane rating fuel in a NEW car can deliver better fuel consumption and engine performance, and some of the additional additives in the premium fuels also help to keep components cleaner and better lubricated. These will all help your engine run more smoothly and last longer. But the jury is still out on the cost vs benefit.
In older cars however, there may be no difference in performance or efficiency.
So there you have it: While cheaper fuel is not bad for your car the difference with the more premium brands is that they can improve economy and give you more mileage for your money (but at a higher cost).