There are several items on the list of things that haven't changed. Some are good, while some still need attention. On the positive side, the TSX's sublime short throw 6-speed shifter carries forward unchanged and continues to be one of my personal favorites in terms of feel and precision. It is coupled to the motor through a nearly flawless clutch. The chosen ratios of the 6MT remain the same for '06. While the ratios seemed to be a bit short on the '04-'05 TSX, they now seem like a more appropriate match for the zestier '06 motor. Unfortunately, the throttle lag in the TSX's drive by wire system hasn't been fixed yet. Many drivers may not even notice it, but it quickly becomes apparent during max acceleration runs. We found that the easiest way to extract the best acceleration figures was to upshift without lifting, but at the same time we must emphasize that this is NOT a recommended technique for daily driving. This WILL lead to accelerated wear on your transmission and can also increase the probability of catastrophic mis-shifts. We only tried this technique on a couple of our acceleration passes, but according to our results this technique clearly resulted in nearly a 0.5 second improvement in the 0-60 and 1/4 mile times.

Finally, a 5AT to test
We never had the chance to fully test a 5AT version of the '04-'05 TSX, but the first '06 TSX we got our hands on was a 5AT Sportshift model, and overall we liked it. The gear ratios are longer and (naturally) spaced further apart than the 6MT, lending the 5AT car a bit more of a relaxed feel. Shifts are smooth, quick, and confident. At part throttle and in typical around town traffic, there's plenty of pep. Thanks to the trip computer, we noticed that the 5AT easily averaged over 25mpg in our suburban driving loop and over 33mpg at a steady 75mph cruise - both figures are a few notches better than the 6MT. The 5AT's transmission logic seems to be biased towards economy and refinement rather than all out performance, as it tends to upshift a bit short of the redline when left to its own devices. As you can see on the dyno charts on the next page, this motor is making good power all the way to the rev limiter, so obviously to extract the maximum performance from it, it's best to upshift as close to the limiter as possible. During our acceleration testing we were able to shave a full second off the 0-60 time by pushing the transmission selection lever over into the sportshift mode. This wasn't as easy as it sounds, because there is a bit of a lag in the sportshift system, so the timing is critical for upshifts, particularly on the 1-2 upshift.

One other curiousity that continues with the TSX's K24A2 is the way the starter seems to struggle a bit to turn over this relatively high compression (10.5:1), long stroke motor and you may find yourself cranking the motor over a bit longer than you might be accustomed to with Hondas. It's most noticeable on cold mornings when the battery's not in its most energetic state. We can't see any real problem with it, but it does seem to be a bit out of character.

Chassis

From a chassis standpoint, the original TSX was so good out of the box there really wasn't much that needed to be changed. The car turns in so eagerly that it's easy to forget you're at the helm of a front-wheel drive sedan. Even with relatively compliant springs and dampers (and a very composed ride), the TSX slithers through corners effortlessly and begs for more. The steering ratio feels about perfect, and while it's not explicitly claimed by Acura, for 2006 there seems to be a bit of additional heft to the steering feel. Combined with the newly beefed up steering wheel, this additional heft lends a bit of a sportier feel to the car. In steady state cornering the meager limits of the all-season Michelin tires reveal the TSX's ultimate tendency towards mild understeer, but until you reach that point the car feels amazing and just begs for more corners. It's a shame that there's no high performance "summer" tire option for this car, because if you fit a good set of tires on it, the car responds amazingly well. We have been running url=tires/Sizes.jspmake=Michelinmodel=Pilot+Sport+PS2partnum=245YR7SPORT2">Michelin Pilot Sport PS2s on our project TSX and overall they are some of the best tires we've ever tried. They complement the TSX's chassis extremely well and we highly recommend them.

It's Time to Rethink the Brake Pads
One item that has escaped Acura's attention is the TSX's brakes. We're going to be brutally honest: the stock brake pads are pretty bad. The feel is okay, but they provide somewhat weak stopping power and are prone to overheating easily (particularly when slowing from freeway speeds). When they overheat, they tend to leave deposits on the rotors, which can lead to a very noticeable and irritating brake shudder. Many people misdiagnose this problem as rotor warpage, but as we proved on our own car, it's really the stock pads chubbing the rotors. It only took a few thousand miles for this problem to appear on our TSX project car, and these were very gentle miles. While the symptoms felt almost exactly like rotor warpage, we decided to swap out the stock pads for some more aggressive aftermarket pads, and the results were simply astounding. Without any rotor resurfacing, the brake shudder and wobble disappeared almost immediately, and within a few days of normal driving, all of the OEM pad deposits were wiped clean from the rotors. To this day, there has been absolutely no brake shudder and brake fade is a thing of the past. Even more impressively, the car has benefitted from a tremendous improvement in braking power. The only downside to this pad upgrade is that the new pads will squeak in very rare circumstances and they generate appreciably more brake dust than the stock pads. Otherwise they are one of the biggest "bang for the buck" modifications out there for the TSX and we highly recommend it. We installed Axxis Ultimates on our TSX, but similar results are likely with any number of other aftermarket fitments.

In Summary
Overall, while the improvements for 2006 have been fairly subtle, everything that has been changed results in increased driving enjoyment. Furthermore, Acura engineers have managed to improve the experience without upsetting the wonderful harmony of the TSX. While we were hoping for a larger dose of extra speed, the 2006 TSX's spirit has been enhanced to an extent that may not be fully represented by test figures.