The seventh ratio is called ___________.

The seventh ratio is called ___________.

• A. driven-overdrive
• B. underdrive
• C. direct drive
• D. overdrive

Answer: (C)

In a multi‑gear transmission, the top gear (often the seventh in a seven‑speed setup) is designed to let the engine run at speeds close to the wheel speed without gearing up or down. This is called direct drive, a 1:1 ratio where engine speed and driveshaft speed match. Because there’s no multiplication or reduction of engine torque, the engine can maintain cruising speeds with moderate RPM, which helps with fuel efficiency and smoother operation on highways. Overdrive would be a ratio less than 1:1, meaning the engine would turn slower than the driveshaft, which isn’t the standard top gear for most seven‑speed layouts. Underdrive has a ratio greater than 1:1, causing the engine to run faster than the driveshaft, which is not how top gear is used. The term driven‑overdrive isn’t a conventional label for the seventh ratio, so it’s not the appropriate term here.

In a multi‑gear transmission, the top gear (often the seventh in a seven‑speed setup) is designed to let the engine run at speeds close to the wheel speed without gearing up or down. This is called direct drive, a 1:1 ratio where engine speed and driveshaft speed match. Because there’s no multiplication or reduction of engine torque, the engine can maintain cruising speeds with moderate RPM, which helps with fuel efficiency and smoother operation on highways.

Overdrive would be a ratio less than 1:1, meaning the engine would turn slower than the driveshaft, which isn’t the standard top gear for most seven‑speed layouts. Underdrive has a ratio greater than 1:1, causing the engine to run faster than the driveshaft, which is not how top gear is used. The term driven‑overdrive isn’t a conventional label for the seventh ratio, so it’s not the appropriate term here.