Not for points English to Japanese Tech/Engineering Automotive / Cars & Trucks エンジン始動�

お知恵拝借したく、お願いいたします。
下記記事の中にある「slurry shift」に適当な日本語を教えてください。slurry自体は「泥水、懸濁液」とありますが shiftを形容すると、どういう日本語が適当でしようか？

But an engine cannot propel a car by itself—the transmission plays a role, too, and in this case, the Q50’s seven-speed automatic has some more rehearsing to do. That it’s down one ratio compared with the gearboxes in competitors such as the BMW 340i and the upcoming Audi S4 is no big deal, but the fact that it serves up some surprisingly slurry shifts, even in Sport and Sport+ driving modes, is of more concern. (The other chassis modes include Standard, Eco, and Snow.)