Rate Adaptation is a critical component of IEEE 802.11 network devices. There are many rate adaptation algorithms proposed in the literature. They are either evaluated through simulations or through experiments only in static scenarios. We implement some of these algorithms (which are implementable) in Madwifi device driver and then compare their performance in static as well as mobile vehicular scenarios. We also present a novel rate adaptation algorithm called RAM. RAM is a per-packet receiver based rate adaptation algorithm. To the best of our knowledge, this is the first receiver based rate adaptation algorithm that is implementable at the device driver level.