Fuel price hike: Is it safe to switch or mix fuels for savings?

Jakarta (ANTARA) - The increase in non-subsidised fuel prices amid geopolitical dynamics in the Middle East region is prompting some vehicle users to consider cost-saving measures, including switching or mixing types of fuel. However, an automotive expert from the Bandung Institute of Technology, Yannes Martinus Pasaribu, warns that such steps pose risks to engine performance and longevity. According to Yannes, switching from higher-octane fuel to a lower one can directly impact vehicle performance. “The main risk of switching to a lower-octane fuel type in vehicles is excessive engine heat, a drastic drop in power, and ironically increased fuel consumption,” he said when contacted by ANTARA in Jakarta on Monday. This risk is said to be greater in high-specification vehicles. Yannes explained that sports vehicles with turbochargers or high compression ratios are more prone to internal engine component wear, such as piston rings, if using fuel not matching the specifications. Besides switching fuel types, the practice of mixing fuels, such as Pertamax Turbo with Pertamax, for example, is also not recommended. He explained that mixing two types of fuel can result in unstable octane levels. In the medium term, this condition triggers performance degradation, uneven combustion, and sporadic knocking – irregular knocking sounds in the vehicle engine. Additionally, deposits can form that clog filters and increase the potential for damage to high-pressure injection systems like Common Rail or GDI. Yannes emphasised that mixing fuels is not an effective cost-saving solution but merely postpones problems and potentially accelerates damage. “It is wiser to choose one type according to the specifications set by the manufacturer,” he said. PT Pertamina (Persero) has raised prices for several non-subsidised fuel products, namely Pertamax Turbo, Dexlite, and Pertamina Dex, starting Saturday (18/4). Quoting Pertamina’s official website in Jakarta on Saturday, the price of Pertamax Turbo for the DKI Jakarta region as of 18 April has risen to Rp19,400 per litre from Rp13,100 per litre on 1 April 2026. For Dexlite, the price is set at Rp23,600 per litre, up from Rp14,200 per litre on 1 April 2026. Meanwhile, for Pertamina Dex, the price is set at Rp23,900 per litre from the previous Rp14,500 per litre. Meanwhile, the price of Pertamax (RON 92) fuel remains at Rp12,300 per litre and Pertamax Green at Rp12,900 per litre. Pertamina is also maintaining the prices of subsidised fuels, namely Pertalite at Rp10,000 per litre and Biosolar at Rp6,800 per litre.