Using Petrol with an Octane Rating Too Low Could Trigger Engine Detonation

Jakarta – The use of fuel with an octane rating not in line with the manufacturer’s recommendations remains common among motorists. Usually, this is done to save costs by choosing petrol with a Research Octane Number (RON) lower than advised. In fact, this habit can lead to engine problems, including detonations, often referred to as ‘knocking’. Detonation occurs when the fuel‑air mixture begins to burn on its own, not following the spark from the spark plug. Tri told Kompas.com on Thursday, 5 March 2026. Tri explained that fuel with a higher RON has better resistance to detonation. Conversely, petrol with a lower RON is more prone to uncontrolled combustion inside the engine’s combustion chamber. This condition is typically characterised by a knocking sound when the engine is operating, especially under heavy driving or high ambient temperatures. In the short term, these symptoms may manifest only as a loss of performance. One of the parts most vulnerable to damage is the piston. Tri explained that pistons are generally made of aluminium, which has a relatively low melting point compared with steel. As a result, the high temperatures produced by abnormal combustion can accelerate damage to this component. “If this happens repeatedly over the long term, the engine can suffer rapid wear. The weakest component in the combustion chamber is the piston because it is made of aluminium,” Tri said. Therefore, Tri urged vehicle owners to use fuel in line with the manufacturer’s recommendations. Besides preserving optimal engine performance, this measure also helps prevent damage from non-ideal combustion within the combustion chamber.