Comparison of First Gear Performance for Manual and Standard Transmissions

by Matthew Endres

Submitted : Spring 2011

The goal of this project was to determine the advantages and disadvantages of a manual or automatic transmission in otherwise identical cars. The manual transmission had a first gear ratio of 4.2:1, while the automatic was 2.86:1. The rear-end ratio was 3.55 for both cars, and the torque vs. RPM curve was provided. I used several equations and calculus to convert the given data to show the velocity of the cars over time.

I found that while the automatic had a first gear redline speed that was considerably higher than the manual, the manual reached the redline RPM in about half the time. This proves that a lower drive ratio will result in faster acceleration, but a higher drive ratio provides a higher top-end speed once the engine is at redline.

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