Most manual transmissions use a case made from which material?

The use of cast aluminum for manual transmission cases is primarily due to its favorable properties such as lightweight, corrosion resistance, and good thermal conductivity. Aluminum's reduced weight compared to steel or cast iron contributes to overall vehicle efficiency, allowing for better fuel economy and handling. Additionally, aluminum's ability to dissipate heat effectively helps in managing the temperatures generated during the operation of the transmission, which is critical for maintaining performance and longevity.

Moreover, cast aluminum can be molded into complex shapes, enabling better design and integration with other components in the drivetrain. This process also helps minimize the number of parts required, leading to simpler assembly and potential cost savings in manufacturing. Other materials, while still used in some applications, do not offer the same combination of benefits as cast aluminum in modern manual transmission designs.