Which type of fluid goes in an automatic transmission?

Automatic Transmission Fluid (ATF) is specifically formulated to meet the unique lubrication and cooling requirements of an automatic transmission. This specialized fluid serves several critical functions, including providing hydraulic pressure to facilitate gear shifting, lubricating internal components, and helping to maintain optimal operating temperatures by dissipating heat.

ATF contains additives that enhance its performance under varying temperature conditions, ensuring consistent shifting and protecting metal components from wear and tear. This formulation is crucial because the automatic transmission operates differently than a manual transmission, relying heavily on hydraulic pressure to engage and disengage gears.

In contrast, options like DOT fluid are used for brake systems and are not suitable for transmissions, hydraulic fluid encompasses a broader range of fluids not necessarily designed for automotive transmissions, and motor oil is used in the engine, not in the transmission. Thus, the correct choice is ATF, as it is the necessary fluid type that fulfills the specific demands of an automatic transmission system.