Drivers may not notice when their vehicles are running on substandard fuel because changes in colour or smell do not reliably reveal the fuel’s chemical quality.
Maxim Kadakov, Editor-in-Chief of Za Rulem magazine, said fuel containing excessive impurities can damage engine components gradually, often without causing an immediate change in vehicle performance.
He explained that drivers may continue to experience normal acceleration and engine operation even when the fuel is contributing to long-term mechanical deterioration.
Sulfur and Other Impurities Can Damage Engine Components
Fuel containing excessive amounts of sulfur, benzene or aromatic hydrocarbons can affect a vehicle’s exhaust and emissions systems.
The catalytic converter and oxygen sensors, also known as lambda probes, are among the first components exposed to the effects of these impurities.
These parts are designed to operate within specific chemical conditions. Fuel containing substances outside the required standards can contaminate the catalytic converter and shorten its operating life.
Continued exposure may also accelerate wear inside the engine, potentially reducing its lifespan below the manufacturer’s expected specifications.
Engine Knocking Can Indicate an Octane Problem
Kadakov distinguished chemical contamination from problems caused by fuel with an octane rating below the engine’s requirements.
A driver may detect an octane-related problem through metallic knocking or pinging sounds, particularly when accelerating quickly or driving uphill under heavy engine load.
This occurs when fuel ignites prematurely or unevenly inside the engine, creating detonation and placing additional stress on components such as the pistons.
Unlike some chemical impurities, which can damage emissions equipment without obvious warning signs, an unsuitable octane rating may produce audible knocking soon after the fuel is used.
Modern Engines Can Be More Sensitive to Poor-Quality Fuel
Modern vehicles are particularly vulnerable to fuel that does not meet the required specifications.
Their fuel injection systems and electronic control units are calibrated to operate within precise limits. Deviations that older carbureted engines might tolerate can cause serious problems in newer vehicles.
Fuel Quality Documents Provide a Way to Check Compliance
Drivers seeking to verify fuel quality before filling their tanks are advised to inspect the fuel quality passport available at the filling station.
According to the report, the document should be checked for three key details:
- Environmental class: The fuel should meet at least K5 standards, equivalent to Euro 5, to ensure lower sulfur content.
- Document date: The date on the quality passport should correspond with the station’s most recent fuel delivery.
- Chemical composition: Sulfur and resin concentrations should remain within the maximum limits specified by the applicable technical standards.
Laboratory testing remains the method for directly verifying the chemical composition of fuel, while the quality passport provides drivers with documented information about the supplied batch.
