A combined vehicle-speed and engine-speed indicating device that replaces or supplements the function of a manufactured vehicle's existing radial-dial tachometer and radial-dial speedometer with a single coordinate field and two translating indicators that follow paths set to a vehicle's set of overall-gear ratios correlating with each of its transmission's driver-selectable gears to give a vehicle's driver a tool by which to optimize selection of gear ratio, engine speed, and vehicle speed for smooth and efficient progress in a vehicle.