Yes, riding a motorcycle slowly at the highest gear can increase fuel consumption. When you ride a motorcycle at a low speed in a high gear, the engine has to work harder to maintain the speed, which can lead to higher fuel consumption.
Motorcycles are designed to operate efficiently within a certain range of engine speed (RPM) and gear ratios. Riding at a low speed in a high gear can cause the engine to operate at a lower RPM than its optimal range, resulting in decreased fuel efficiency. Additionally, the throttle opening required to maintain speed in a high gear at low speeds can lead to the engine running at a less efficient point on its power curve.
To achieve better fuel efficiency, it is generally recommended to ride at an appropriate gear for the given speed. Riding at a lower gear in situations where the engine is lugging or struggling can help maintain better fuel efficiency. Additionally, it's important to consider factors such as traffic conditions, road gradient, and the specific characteristics of your motorcycle when determining the appropriate gear for a given situation.