What is the difference between a transmission and an engine?

[EmmanuelFitz]

The difference between a transmission and an engine lies in their functions: the transmission changes the gear ratio, while the engine serves as the power source of the vehicle. The relationship between the transmission and the engine is that the engine delivers power to the transmission, which then controls and transfers this power to the wheels. The transmission is a mechanism designed to alter the speed and torque from the engine, capable of fixing or changing the gear ratio between the output and input shafts. It is categorized into stepped transmissions, continuously variable transmissions (CVT), and integrated transmissions. The engine is a machine that converts other forms of energy into mechanical energy, and it is classified into external combustion engines, internal combustion engines, gas turbines, and jet engines.

[StMatteo]

I've driven many cars, and the engine is like the heart of a car, burning gasoline or diesel to generate power and propel the vehicle forward; the transmission acts like a smart brain, adjusting the rhythm and intensity of this power to ensure smooth operation at different speeds. For example, when you press the accelerator to speed up, the engine roars, but the transmission shifts gears to change the gear ratio, ensuring efficient power delivery to the wheels. The engine is usually installed separately at the front of the car, requiring maintenance checks on spark plugs or engine oil; the transmission is connected at the rear and can sometimes accumulate carbon deposits or experience oil leaks. If the engine fails, the car won't move, while transmission issues may lead to rough shifting or increased fuel consumption. In daily driving, the engine determines the power output, and the transmission controls smoothness—only when both work well together can driving be comfortable and safe.

[Danielle]

I think understanding these two components is quite simple. The engine is the source of power generation, just like a chef needs a stove to heat up when cooking; the transmission is a tool for adjusting power, similar to a switch controlling the heat level to prevent food from burning or being undercooked. When driving, the engine burns fuel to output energy, while the transmission converts the power into appropriate speeds through a gear system—it shifts to lower gears for more torque when climbing hills and to higher gears for fuel efficiency during high-speed cruising. The engine is usually located under the hood with a long maintenance cycle, while the transmission is closer to the chassis, requiring more frequent maintenance and prone to minor issues. Distinguishing them is crucial because neglecting transmission maintenance can lead to jerky shifts, affecting the driving experience.

[HavenLee]

From a maintenance perspective, there is a significant cost difference between the engine and transmission. The engine is the power core, and faults like oil leaks or overheating can cost a lot to repair or replace. The transmission regulates power output; if gears are worn or fluid paths are blocked, repairs might be cheaper but are prone to recurrence. The engine is easily identifiable at the front of the car and requires regular oil changes for maintenance. The transmission is hidden near the driveshaft, and its maintenance requires professional tools to prevent damage. The key difference lies in the engine generating initial power, while the transmission optimizes the process of delivering it to the wheels. Ignoring these distinctions may lead to sudden jerks or unresponsive acceleration while driving.