While the aesthetic aspects of the TSX will likely go a long way towards punching 15000 $25-30k holes in people's wallets, it's on the road where the car will really win sales. Key the motor to life and it quickly fires and settles to a nice muted burble. Release the parking brake, pull away, and immediately you can sense that this is no ordinary 4-cylinder sedan. It moves with a fluidity and confidence that betrays its $25000 price tag. At the same time, you are able to sense the supreme stiffness of the chassis (exceeding basically everything in its class), and the reassuringly solid feel it provides. Acura claims that stability and ride comfort both exceed the standards set by BMW's 3-series and Audi's A4. After driving the car, I'll take their word for it.

Under the hood, the reserve of torque availed by the 2.4L DOHC i-VTEC motor (yes, Martha, VTEC operates on both cams, just as in the RSX Type-S) is immediately obvious. The dual balancer shafts effectively quell the n^th order harmonics that plague 4-bangers. These harmonics can be quite considerable in a 4-cylinder of such a large displacement. You won't mistake the motor for an inline 6-cylinder, but there are some V6s that could take a few hints from the smooth operation of this K24A2 (cough! VQ35 cough!!). The exhaust system is tuned to emit pleasingly subtle sounds of the big 4, sounds which emanate from two attractive exhaust tips. The cable-actuated 6-speed shifter is typical of Honda, which means it offers a great feel and class-leading short throws. The clutch feel is also quite good, engaging precisely and smoothly. Acura also utilized a dual mass flywheel to dampen driveline shock upon shifting. The only complaint I might register at this point has to do with the throttle action.

Thanks to space-age technology involving tiny little silicon devices called "microchips", the throttle plate is not connected by direct mechanical linkage to the (bottom-hinged) gas pedal. Instead, the TSX employs a throttle-by-wire system that replaces the (old-school) throttle cable with a conducting wire that propagates a stream of electrons from a sensor attached to the gas pedal to a servomotor inside the throttle body. This fancy "throttle-by-wire" system opens up a host of possibilities in terms of computer intervention. From a driving standpoint, the system allows the throttle to employ several different "profiles" which cause the throttle plate to crack open in a non-linear fashion with respect to gas pedal inputs, depending upon the situation (see graphs). At lower speeds, to reduce lurching in traffic, the throttle actually responds slower than your foot dictates, so tip in isn't so harsh. On the freeway, it's nonlinear in the opposite direction, reacting more aggressively at the center of the range to provide a sense of improved response and power when you need to make a pass. The "drive-by-wire" system also works in concert with the cruise control and VSA (Vehicle Stability Assist) system, which is there to deal with wheelspin and also to stabilize the vehicle if the need arises. I don't pretend to fully understand this enigma wrapped in a mystery, shrouded in ABS plastic, but apparently the engineers had to go this throttle-by-wire route to meet the power goals without violating the strict LEV-2 emissions target.

Now, on to my complaint about the throttle action: it seems that there may have been a few bugs left in the "profiling" code of our pre-production prototypes, as smooth getaways were occasionally glitched by this 21st Century computer intervention. Once underway, throttle response is very good, and the system operates transparently, which is How It Should Be. Other "throttle-by-wire" systems I've driven have left me fuming. And by "other" systems, I might be referring to the 2003 Mercedes E-Class' drive-by-wire. With the E-, I had the sensation that the gas pedal was connected electronically to the throttle plate, by a dial-up transatlantic modem connection, backhauled over a satellite link. Fortunately, there's no such perceivable lag in Honda's throttle-by-wire system.

The VSA system is one of the better traction control/vehicle stability systems I've encountered. In fact, its operation goes virtually unnoticed, which is how it should be. Only periodically would you even notice the icon flashing on the instrument panel. Without the indicator light, you'd likely never even know the system was working.

The TSX uses a hotter version of the now-familiar K24, and it should satisfy most drivers. In addition to carrying peak power through frenetic RPMs, it's designed to deliver its power more consistently across the rev range. It moves the TSX rather well, delivering plenty of oomph for most situations at just about any RPM. Through the hills, the motor provides ample tug, even in upper gears. High rpms are there if you want them, but they're not a requisite for speed. If you're feeling frisky, the car revs willingly right up to its 7100 RPM redline (and a bit beyond, into the limiter at an indicated 7500 RPMs or so - of course the tach is probably optimistic by a couple hundred RPM), with a 2nd wind coming online right around 6000 rpms, just as you think the power might be tapering off. It's not the same sort of kick that most people associate with DOHC VTEC motors, or even the RSX-S' K20A2, but rather it feels like an extension or continuation of the torque curve. The gear ratios in the 6-speed manual transmission seem to have been selected well for the car's intended purpose. 6th gear provides plenty of leg for highway duties, yet the motor retains a sufficient reserve of torque to minimize the need to downshift during passing situations. For those interested in straight-line acceleration figures, Acura figures the car to be a half step behind a 325i, but well ahead of the Audi A4 1.8T. I anticipate 0-60 times of the 6MT model to be in the 6.8-7.0 second range, but I will not be able to verify these until we have a chance to do a full road test on the TSX. I found the power to be adequate, but I'm accustomed to driving quicker cars, so I was personally hoping for a 240hp version of the TSX, perhaps a Type S version. Fortunately the K24A2 is a very close cousin to the RSX-S's K20A2, which to date has responded phenomenally to bolt-on upgrades. I expect the K24A2 to also respond quite well to the same sort of tricks that work today on the K20A2. I wouldn't be surprised to see 210 or even 220 horsepower at the wheels from a modified (computer, intake, exhaust, header, maybe cams) K24A2.

Acura expects 30% of buyers to opt for the 6MT, with the balance ordering the 5-speed Sport-Shift. I briefly drove a TSX equipped with the Sport-Shift, and I came away pleasantly surprised by how well it performed. Honda's automatic transmissions have really come a long way in the past few years, and this one is no exception. In contrast to the the CL and TL's Sport-Shifts, the TSX's allows you to select 1st gear. It executes upshifts and downshifts crisply and cleanly, and the torque converter feels pretty tight. Compared to the 6-speed, there seems to be little penalty in the way of acceleration, which is somewhat remarkable in a 4-cylinder car. Several advancements have been made to the torque converter which directly impact fuel economy and performance. The system is now able to lockup much sooner in the top four gears. This directly results in a 2 percent improvement in fuel economy in both the city and highway EPA cycles. Couple this advancement with the taller final drive ratio, and the fuel economy numbers of the automatic-equipped TSX are actually better than the 6MT on both EPA cycles. Furthermore, the throttle-by-wire system is credited with the remarkable smoothness and quickness of shifts. In fact, Acura claims a 40-percent improvement in the 2-1 shift time, dropping from 1.15 second to 0.7 seconds.