TLX 3.5L SH-AWD
We were generally quite impressed with this version of the TLX, though we could certainly feel the additional weight of the V6/9AT/SH-AWD powertrain. The difference in weight between this model and the 4-cylinder TLX that we drove is around 280lb, but for some reason it felt like more than that. The additional weight of the V6 AWD powertrain was evident every time we asked this car to change directions - it simply didn't transition with the same effortless sensation as the 2.4L version. That's not to say that it was less capable than the 2.4L TLX, it just felt like its maximum performance was less accessible, to a degree.
If you don't care so much about turning, acceleration with the 290hp V6, SH-AWD, and all-new 9-speed automatic transmission is quite good, though honestly we thought the new powertrain and weight loss would result in a greater boost in performance than the 0.3 second improvement that Acura claims.
The engine makes nice sounds while pressed and always maintains its composure. The ZF-sourced 9-speed transmission is fantastic under acceleration, but when you need to overtake a slower moving vehicle or if you are looking for some engine braking we found that it may require a bit of forward planning. When cruising along at a steady speed, obviously the transmission will find its way to the highest possible gear (and it finds 9th quite frequently). At 70mph you will be turning well under 2000rpms in 9th, so obviously a passing situation will require a multi-gear kickdown. If you're dealing with a short passing zone on a two lane road, you will definitely want to gear down with the paddle shifters to anticipate the pass. Otherwise if you rely upon an automatic kickdown, it takes an extra heartbeat to kick down the 3 to 5 gears required to effect the pass. As for the latter issue concerning engine braking, a specific scenario I can describe was where we crested a hill at a fair clip, gained some speed as we descended the hill, and then tried to gear down with the paddle shifters to slow the TLX's descent as we approached a right-hander. The 9AT basically freewheeled as I frantically tried to call for sufficient downshifts to slow the car in time for a graceful corner entry. Ultimately I had to stab the brakes, as the transmission never downshifted quickly enough to effect an adequate level of engine braking. (Side note: If you are driving with IDS set in Sport+ mode, the transmission will automatically gear down as you apply the brakes, to assist in slowing down, and add to the "racy" feel of Sport+.) This situation presented itself multiple times throughout my drive. Which leads to the next issue.
We need stronger Brakes
For an everyday driver, the TLX has sufficient brakes, but under "sporty" driving circumstances, it's not difficult to generate enough heat to fade them fairly early in a spirited drive. And though this is being mentioned under the 3.5 SH-AWD comments, this criticism generally sticks with all 3 versions of the TLX. After an all-too-brief period of time where Acura engineers specified some reasonably powerful brakes on their cars, they seem to have reverted to the practice of the old days where the brakes were rather underpowered.
Unfortunately, with the 2015 TLX, the brakes just don't quite seem beefy enough for extended sporty duty. Effort levels are light, but that's not the main problem. The braking interface itself feels a bit flimsy, especially compared to the competing vehicles that Acura brought to the event (2014 Infiniti Q50, 2015 Lexus IS250, 2014 BMW 328xi). This is unfortunate as there was a brief period where Honda and Acura seemed to be taking braking system performance more seriously. Hopefully this will be addressed.
SH-AWD version 2.0
Acura's update to their Super Handling All-Wheel-Drive system performs as advertised. Responsiveness does indeed seem to be improved, particularly from a standing start. For example, upon departing our lunch spot, we had to make a left turn across a busy 50mph road, so I picked a gap in traffic, matted the throttle and it surged forward immediately, notching the rear end out to a slight degree as I cranked the wheel to the left, giving it a nice rear drive feel.
On the twisties, we didn't have a lot of opportunities to fully flesh out the system due to slow moving traffic, but the few times I was able to push a little harder, it felt similar to the previous generation SH-AWD system in that it felt like you had to overdrive the car a bit to get the maximum effect of the SH-AWD system. Unfortunately, this car will not make you completely forget that it is based on a transverse FF layout. The competitors Acura had on hand felt more natural, poised, and intuitive than the V6 TLXs on the winding roads.
With upsized 18" wheels, the SH-AWD TLX brings a bit more styling flair to the table than the 4-cylinder model. It also brings a serious jump in power and torque, on top of the traction benefits of the SH-AWD system. Ultimately, it will probably out-corner the 2.4 model as well, but from a seat of the pants feel, the TLX 2.4's additional athleticism and perfectly optimized powertrain is what nudges it ahead of the SH-AWD model in our book.
TLX 3.5L P-AWS
Yes, the front-wheel-drive 3.5L P-AWS comes in third here, but that's not to say it's a bad car by any stretch. The key reason it's our least favorite is that it exhibits most of the things that bother us about high powered front-wheel-drive sedans. Too much weight on the nose + a lot of power means you will easily surpass the mechanical grip afforded by the front tires. This car is fine at a medium-brisk pace, but the chassis struggles to balance everything out when the corners tighten up. I would recommend this car if you are merely looking for a comfortable cruiser with lots of luxury and power.
Overall, Acura did a nice job combining the TSX and TL to create the TLX, while building upon the virtues that made the 1st generation TSX and 3rd generation TL so desirable in the first place. For those who generally favored the TSX, the TLX with the new 2.4L engine and 8-speed DCT is a really entertaining package, with unsurpassed levels of comfort and refinement. For those who loved the 3rd generation TL (and the 4th-gen TL SH-AWD 6MT), the TLX V6 brings new highs in refinement, efficiency, and driving enjoyment. The one thing that's missing from the TLX (and this could be a dealbreaker for a tiny fraction of the prospective customer base) is the availability of a 6-speed manual transmission.
We'd like to see one or more Type-S variants for the TLX. One possibility that piques our interest would be a 2.0L Turbo (borrowed from the upcoming Civic Type-R) version with SH-AWD and a 6-speed MT or a DCT of some sort. If the engineers could make this package feel as nimble and balanced as the TLX 2.4, we think it would make for an incredible luxury performance sedan.