Downshift to overtake: Avoid the common driving mistake that harms engines

Good driving techniques can lead to fuel savings and reduced vehicle wear and tear. However, even experienced drivers can make mistakes due to bad habits. One common error is failing to downshift before accelerating.

An empty road, a car with decent performance, and the need to overtake a slower vehicle: In such situations, drivers do not always decide to downshift before accelerating. They assume they have enough time and space for the maneuver and that the car will speed up sufficiently when the gas pedal is pressed to the floor. However, this is a mistake that adversely affects the engine.

Drivers also mistakenly believe that accelerating at lower RPMs is more beneficial because it generates less noise from the exhaust system. However, it should be noted that a high load at low RPMs is not advisable for the engine. In such operating ranges, the engine works less efficiently. More energy from the fuel is used to generate heat rather than acceleration, which results in higher fuel consumption and engine overheating, especially the internal parts of the cylinders.

This overheating leads to uneven combustion of the fuel-air mixture and ignition problems. Consequently, forces in the cylinder are distributed unevenly, accelerating engine wear. This is particularly detrimental to turbocharged engines, which are standard in modern cars. It also increases the risk of pre-ignition of the mixture.

Two Japanese companies, Toyota and Denso, a manufacturer of spark plugs, have studied the issues arising from accelerating without downshifting. Research has shown that in such cases, glowing fuel and oil residues may remain in the engine. At low RPMs, these residues are more likely to cause pre-ignition, leading to faster wear of pistons and spark plugs.

The necessity of downshifting before accelerating is also emphasized during driving courses. Overtaking is a dangerous maneuver that requires dynamic and rapid completion. Therefore, downshifting is crucial to maximize the car's acceleration and safely and quickly overtake a slower vehicle.