在探讨自动变速箱技术之前,D 级,即D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D级,D