The 7-speed automatic transmission includes a manual shift mode, paddle shifters and Downshift Rev Matching. The 6-speed manual transmission includes SynchroRev Match synchronized Downshift Rev Matching system. Part-throttle downshift was added to the 8-cylinder automatic transmissions. This shift in frequency is called a Stokes shift, or downshift. In 1968, part-throttle downshift functionality was added to A-904 transmissions used with six-cylinder engines. It can also automatically downshift before overtaking. Changes include downshift "rev matching", slightly altered gear ratios, and a different bellhousing. Downshift are accompanied with automatic rev-matching. The automatic added downshift rev-matching system also in 2014.