What are the symptoms of insufficient low-speed torque?
2 Answers
Insufficient low-speed torque means the torque output is too weak at low RPMs. The performance characteristics of such vehicles include lack of power when lightly pressing the accelerator, and the car not moving forward with gentle throttle input. Generally, small-displacement naturally aspirated engines have relatively weak torque at low RPMs, and some large-displacement naturally aspirated engines also exhibit this characteristic. Turbocharged engines, which can deliver maximum torque at very low RPMs, demonstrate superior low-speed torque performance. The introduction to turbocharging is as follows: 1. Development history of turbocharging technology: The power output characteristics of turbocharged engines differ from naturally aspirated engines, which is why many consumers prefer models equipped with turbocharged engines. The power delivery of turbocharged engines is more suitable for stop-and-go urban driving conditions. Turbocharging technology was originally developed for aircraft engines to address insufficient air intake at high altitudes. 2. Turbocharging principle: Turbocharged engines are equipped with turbochargers, which consist of two main components - a compressor turbine and an exhaust turbine. When the engine reaches certain RPMs, the exhaust gases have sufficient energy to drive the exhaust turbine, causing the compressor turbine to rotate and compress air into the cylinders.
The manifestation of insufficient low-speed torque is that the car starts extremely slowly, with no response for a long time after stepping on the accelerator, as if the engine hasn't had enough fuel. It's even worse on slopes—the car struggles to climb and requires heavy throttle input to move, accompanied by a deep roaring sound from the engine, along with body shaking and steering wheel vibrations. In city driving, overtaking or changing lanes becomes difficult due to weak acceleration, and the car lags far behind others when starting from a green light. Even restarting after a stop takes several seconds before the car moves. This also affects driving safety, as the inability to accelerate quickly in emergencies increases the risk of accidents. Additionally, fuel consumption rises because higher RPMs are needed to compensate, making driving over time truly frustrating.
