For the upcoming second-generation 2009 Acura TSX sports sedan, Honda has modified the 2.4-liter engine with a resultant slight reduction in horsepower, an increase in torque, and a slight increase in fuel economy. The vehicle is also cleaner, meeting the Tier 2-Bin 5 and CARB LEV II Ultra Low Emission Vehicle (ULEV) standards for the first time in TSX history.
An all-aluminum DOHC i-VTEC in-line 4-cylinder 2.4-liter engine features a pair of firsts for the TSX model: dual balance shafts and a direct ignition system. Producing 201 hp (150 kW) and 172 lb-ft (233 Nm) of torque (with manual transmission), the new engine produces its usable power across a much wider rpm range, while the 5% more torque further strengthens the engine’s pulling power at middle rpm levels. This allows the 2009 TSX to be more responsive off the line and out of corners, and stronger in the middle of the rpm range where the engine operates most of the time.
This newfound performance and flexibility is due in part to a higher compression ratio, revised valve timing, and improved intake and exhaust gas flow. A new rear-mounted exhaust manifold layout, a close-coupled catalytic converter design, and a Programmed Fuel Injection (PGM-FI) system substantially reduce emissions levels. Estimated fuel economy is 21/30/24 mpg (city/highway/combined, 5 AT) and 20/28/23 mpg (city/highway/combined, 6 MT).
By comparison, the 2008 TSX, with a 205 hp 2.4-liter engine, has fuel economy ratings of 20/28/23 (city/highway/combined, 5AT) and 19/28/22 (city/highway/combined, 6MT).
(A hat-tip to Bob!)