The TSX spanned two generations, both derived from the corresponding Japanese/European versions of the Honda Accord, which were more compact and sporting-oriented than their larger North American counterpart.

The 2004 model year TSX's powertrain consisted of a 2.4-liter inline four-cylinder K24A2 engine which produced 200 horsepower, a six-speed manual transmission (which featured a magnesium casing, to reduce weight), and a front wheel drive layout.

[8] In 2007, Tire Pressure Monitoring System and an improved electronic rear view mirror were added, and the 2008 model year brought a new color option.

2005 was the second year of the TSX and Acura updated it with XM Satellite Radio, a four-way power passenger seat and illuminated the steering wheel-mounted audio and cruise controls.

[9] Along with the slight tweaks to the engine in 2006, interior tech features were also added, including a Multi-information Display (MID) in the instrument panel, and luxury features such as a two-position memory for the driver's seat adjustments which adjusted according to which of two keys were being used, auxiliary MP3 player input and Bluetooth-compatible HandsFreeLink (for cellular phones).

Another feature of the i-VTEC system on the TSX and RSX-s was that, unlike other Honda K-series motors, variable timing was used on both the intake and exhaust cams in its three rocker design.

[16] Making its debut on the new TSX was Honda's Advanced Compatibility Engineering body structure, which was designed to reduce accident impact on occupants.

[19] In 2009, the 2010 model year TSX added an optional 3.5L 280 hp V6 engine, shared with the Acura TL, and which was not available for the CL-series Accord sold in Europe.

Inside included more LED lighting, new LED/VGA navigation screen and system functions with Technology Package, center console HVAC vents for rear occupants, and new trim colors, woodgrain, and metal finishes.

[27] The Acura TSX was slated to receive a high-performance 2.2-liter i-DTEC clean turbodiesel engine in the 2010 model year, after having already offered it for the CL-series Accord sold in Europe.

For the United States market, the 2011 Acura TSX Sport Wagon went on sale starting on December 21, 2010 with a base price of US$30,960 (US$34,610 with Technology Package).

[34][35][29] Changes for the 2012 TSX Sport Wagon include a compact tire repair kit that allows for a significantly larger underfloor storage area.

The 2012 TSX Special Edition is a version of the TSX commemorating the 25th anniversary of Acura, with a 6-speed manual or Sequential SportShift 5-speed automatic transmission, a more aggressive front spoiler, rear bumper fascia and side sills, 17x7.5-inch 5-spoke aluminum wheels with a dark grey finish, a "Special Edition" badge on the trunklid, perforated black Lux Suede inserts and red backing upholstery, unique red stitching and red-lighting throughout the interior, aluminum pedal covers and a black headliner material replaces the standard grey headliner used on other TSX models.

The factory TSX is refashioned to be stiffer and lighter, and includes motor work with raised compression, and a custom built sequential transmission.

Acura returned in 2006 and won the Manufacturers' Championship of the Speed World Challenge Touring Car class for the second year in a row, running both RSXs and TSXs.