As a rule, an automatic transmission is less economical than a manual transmission.
Reasons:
* Torque Converter Losses: An automatic transmission uses a torque converter to convert engine torque into motion. However, it results in energy loss, which reduces efficiency.
* Design complexity: Automatic transmissions are more complex in design than manual transmissions, which requires more parts and lubrication, which again leads to energy loss.
* Increased weight: An automatic transmission is heavier than a manual transmission, which increases drag and reduces efficiency.
Exceptions:
In some cases, automatic transmission may be more economical:
*Modern 8- or 9-speed automatic transmissions: These have more gears, allowing the engine to operate in a more efficient RPM range.
* Hybrid vehicles: The automatic transmission in hybrid vehicles is often combined with an electric motor, which can improve efficiency, especially when driving at low speeds.
*City Driving Conditions: In frequent stop-and-go conditions, such as city traffic, an automatic transmission can be more convenient and efficient since the driver does not have to constantly change gears.
In general, a manual transmission is usually more economical than an automatic, but in some cases an automatic transmission can be more efficient.