本推荐规程定义了一个试验程序和过程，对20世纪自动变速器的效率和性能进行了合理完整的描述。随着电子控制的引入，控制变速箱运行的参数数量已经广泛增加，需要为每次测试定义这些参数。变速箱、环境、发动机、冷却系统和其他系统之间的相互作用也使得测试定义非常困难和复杂。最后，电动和混合动力驱动系统所带来的多样性、快速变化和部件复杂性，再加上上述困难，使得定义一个能够对21世纪汽车变速器的性能和效率进行有意义描述的推荐实践变得不切实际。 正在稳定现行推荐规程J651，以保留试验程序，供将来参考。

This Recommended Practice had defined a test procedure and process which gave a reasonably complete description of the efficiency and performance of a 20th century automatic transmission. With the introduction of electronic controls, the number of parameters which control the transmission’s operation have expanded extensively and these need to be defined for each test. The interaction between the transmission, the environment, the engine, the cooling and other systems have also made test definition very difficult and complex. Finally, the diversity, the rapid changes, and the component complexity introduced by electric and hybrid drive system combine with the above difficulties to make it impractical to define a Recommended Practice which could provide a meaningful description of performance and efficiency of 21st century automotive transmissions. The existing Recommended Practice J651 is being stabilized to preserve the test procedures for future reference.