Overcoming turbocharged temptations: Downshifting for engine health

The almost universal use of turbochargers, which provide "strong low-end torque" (while meeting emissions standards), has become the main cause of driver errors. When the road is clear and the car seems to accelerate well with just a press of the accelerator, we tend to skip downshifting. However, this is a mistake that negatively impacts the engine.

Many drivers believe that accelerating at lower RPM (revolutions per minute) is preferable because there is less noise from the exhaust system. Nonetheless, the engine is not designed to handle heavy loads at low RPM. In these conditions, efficiency decreases — more energy from the fuel is used to produce heat rather than actual acceleration. This leads to higher fuel consumption and increased engine temperature, particularly within the cylinders.

Excessive heating of these components can lead to uneven fuel mixture combustion and ignition problems. Consequently, forces within the cylinder become unevenly distributed, contributing to faster engine wear. Turbocharged engines, which are found in most new cars, are particularly sensitive to this type of acceleration, increasing the risk of pre-ignition of the mixture.

Research conducted by Japanese companies Toyota and Denso has shown that glowing remnants of fuel and oil can remain in the engine when accelerating without downshifting. At low RPM, such particles increase the chance of uncontrolled ignitions, which reduces the lifespan of pistons and spark plugs.

Driving instructors also recommend downshifting before accelerating during courses. Overtaking is a risky manoeuvre that requires a dynamic and swift conclusion. Downshifting lets you utilise the vehicle's full capabilities and rapidly complete the overtaking manoeuvre.