Today’s drivers may never have noticed it, but before modern software transformed car dashboards, many automatic transmissions included a small “E” beside the familiar P, R, and D. It looked insignificant, yet it represented a feature that quietly influenced the way a car behaved.

Some drivers selected it every day without giving it much thought, while others ignored it completely because they were unsure what it actually did. Unlike the more obvious gear positions, the “E” rarely drew attention, even though it could noticeably change the driving experience.

The letter stood for Economy mode. When activated, the transmission shifted to higher gears sooner and kept engine speed lower, helping reduce fuel consumption and create a smoother, more relaxed ride during everyday driving.

Although many newer vehicles now offer Eco modes through buttons or touchscreen settings, that simple “E” was an early version of the same idea. It reminded drivers that they could choose efficiency over performance with a single, easy adjustment.