The Acceleration Device was first introduced in the flagship Acura RL sedan, and continues in the MMC versions of the Acura RL sedan. This more complex configuration appears to be unique among the SH-AWD equipped Acuras. This more complex RL configuration could be considered an exclusive flagship vehicle feature, and not specified for vehicles with lower price points. On the other hand, the later SH-AWD configuration without the Acceleration Device could just be a simpler and less sophisticated version due to vehicle dynamics and price points, or it could represent a more refined, less complex and inherently more reliable, new standard for the SH-AWD configuration. The rationale for the two distinct configurations has not been publicized by Acura.