Since the launch of the XT4 with the rather anemic (if more refined) LSY engine, many (including myself) had questioned why GM does not offer the Tripower 310 bhp / 348 lb-ft (L3B) 2.7T 4-cylinder in the XT4 (at least) as an option. To a lesser extent some have also questioned why the LSY is putting out a mere 237bhp / 258 lb-ft whereas the outgoing LTG engine is good for 265~272 bhp / 295 lb-ft. Is it just so that it can have 258 lb-ft arrive @ 1,500 rpm? Now, we have the answer...
It's the 9-speed Automatics.
Adopting the 9-speed automatics is deemed a priority for refinement and fuel economy. The new GM-Ford 9TXX transmissions, jointly developed with Ford promises better fuel economy and better shift quality. There are currently two versions of this transmission:-
- 9T50 -- 258 lb-ft
- 9T65 -- 280 lb-ft
The need to pack 9-speeds into a very slim transmission case meant that they have to use an ovoid cross section torque converter, a tension chain coupling and abandon the high torque capability of the previous generation top dog 6T80 (369 lb-ft) transmissions used in the 410 hp / 368 lb-ft 3.6L Twin-Turbo (LF3) powered Cadillac XTS. The lack of torque capability is also in part why Ford abandoned the use of the GM-Ford 9TXX transmissions, choosing instead to develop an 8-speed evolution of the decade old 6T80 for use in their high torque applications like the Ford Edge ST (2.7L Ecoboost V6 with 335 hp / 380 lb-ft). Ford also asserts that the new 9-speed autos did not yield any fuel economy improvement when tested with their engines and the refinement improvements alone did not justify the costs and weight increases.