I'm sure the gauge shows both, average and instantaneous. The reason is, the bar (not the one showing the average with number) jumps up and down when you traveling about 20-30 km/h. If you're in US, you are using MPG, which means the bar is always down. That's why you don't notice it's there. If you are using L/100km, the bar is always up, and does jump up/down sometimes when traveling at low speeds such as 20-30 km/h. See pics attached.