The new TSX's size, weight and total performance work in balance. The result is a car that is comfortable for five passengers, yet agile and responsive for performance driving. The same balanced thinking applies to the TSX powertrain. With an advanced in-line 4-cylinder powerplant, TSX offers strong acceleration, combined with low overall weight and compact packaging. Fuel efficiency is also a strong point.

An advanced, all-aluminum 2.4-liter DOHC i-VTEC® in-line 4-cylinder engine produces 201 hp and 172 pound-feet of torque (MT), and incorporates Acura's i-VTEC® "intelligent" valve control system that features Variable Valve Timing and Lift Electronic Control (VTEC®) combined with Variable Timing Control™ (VTC™). Though peak horsepower is virtually unchanged versus the previous generation engine, peak torque output has risen by 8 lb-ft. In addition, the engine's torque curve has fattened considerably. Horsepower, for example, is up five percent at 4,400 rpm. The result is stronger throttle response and better acceleration just about everywhere in the engine's operating range. To achieve these power gains, the engine has a higher compression ratio, new valve timing, and intake and exhaust flow improvements. A new aluminum and resin composite intake manifold reduces weight over the previous aluminum design, while better insulating the engine's incoming airflow from under-hood heat.

Though engine performance has improved, the powerplant delivers better fuel economy and has reduced emissions. A rear-mounted exhaust layout, close-coupled catalytic converter and advanced Programmed Fuel Injection (PGM-FI) team to help the TSX meet strict EPA 2 - Bin 5, and CARB LEV II Ultra Low Emission Vehicle standards (LEV-2 ULEV).

The 2009 TSX comes with a choice of two transmissions – a standard 6-speed close-ratio manual transmission or a Sequential SportShift 5-speed automatic. The manual gearbox has a lightweight magnesium alloy case and multi-cone synchronizers providing a light, quick action with very short shift throws. To provide more spirited driving, the manual transmission now includes more performance-minded ratios for second and third gears.

The 5-speed Sequential SportShift automatic has a new straight-style shift gate (versus the previous TSX's serpentine-style gate design) with Drive and Sport positions that provide fully automatic operation. The transmission can be shifted manually via new steering wheel mounted F1®-style paddle shifters at the driver's option. Also new with SportShift is the ability to use the paddle shifters to make gear changes while in Drive, whereas previously this would only occur when in Manual mode. When using SportShift in Drive, the gear changes are made per driver command, but after a short time (with no further gear change input) the 5-speed automatic transmission returns to its normal Drive mode operation. Working in combination with the Drive-by-Wire™ Throttle System, the Sequential SportShift transmission's shift logic results in quick, smoothly controlled shifts. Grade Logic and Shift Hold Control work in automatic mode to keep the transmission in the gear that's ideal for the driving situation. Further improving performance and drivability is a revised torque converter lock-up assembly.

Long 100,000-mile tune-up intervals and a standard Maintenance Minder™ system, which automatically monitors the vehicle's unique operation condition to indicate to the driver when maintenance is required, help to lessen the cost of ownership. The Maintenance Minder™ system is designed to ensure that important service issues are addressed in a timely manner, and eliminate unnecessary maintenance procedures to help reduce environmental impact and operating expenses.

POWERTRAIN AT A GLANCE

Engine

• 2.4-liter, DOHC, i-VTEC® 4-cylinder engine generates 201 horsepower at 7,000 rpm with 172 lb-ft of torque at 4,400 rpm (MT); 170 lb-ft of torque at 4,300 rpm (AT)
• i-VTEC® "intelligent" valve-control system combines Variable Timing Control™ (VTC™) with VTEC®
• Drive-by-Wire™ Throttle System
• Computer-controlled Programmed Fuel Injection (PGM-FI)
• Dual balance shafts for exceptional smoothness
• Direct ignition system
• Lightweight alloy pistons and high-strength connecting rods
• 100,000-mile tune-up interval (may vary with driving conditions)

• Estimated mileage of 21/30/24 mpg* (city/highway/combined, 5 AT) and 20/28/23 mpg* (city/highway/combined, 6 MT)
• EPA TIER 2 – BIN 5, CARB LEV II ULEV emissions standards
• Rear-facing exhaust ports, close-coupled catalytic converter and under-floor converter provide fast catalyst light-off for lower and cleaner emissions

6-Speed Manual Transmission

• Close-ratio 6-speed manual transmission
• Compact, rigid, lightweight transmission case and bellhousing
• Multi-cone synchronization on all gears for light shifting effort
• Revised ratios for second through sixth gears
• Precise and light shift
• Short clutch pedal stroke with light effort
• Compact clutch with low inertia for quick acceleration

• Sequential SportShift via F1®-style steering-wheel mounted paddles
• 5-position straight shift gate
• Advanced Grade Logic Control for reduced gear hunting when driving on steep hills
• Linear solenoid direct-acting control for reduced shift shock and shift smoothness and responsiveness
• Drive-by-Wire™ cooperative control facilitates quicker shifts
• Lockup torque converter design delivers superior fuel economy
• Shift Hold Control

• Lightweight and durable aluminum cylinder block with cast-in iron cylinder liners
• One-piece aluminum crankshaft carrier for improved strength
• Chain-driven balance shafts mounted on lower block in oil pan
• Maintenance-free silent-chain camshaft drive
• Maintenance-free serpentine accessory drive-belt assembly with auto-tensioner

i-VTEC® VALVE CONTROL SYSTEM

The 2009 TSX's 2.4L engine features Acura's i-VTEC® "intelligent" valve control system. Featuring Variable Valve Timing and Lift Electronic Control (VTEC®) combined with Variable Timing Control™ (VTC™), the system provides power characteristics like those of a V6 without sacrificing the light weight or fuel efficiency of an inline four. A new VTEC® design uses three reduced-thickness aluminum rocker arms that operate a pair of intake and exhaust valves for each cylinder. At low rpm, the valves follow low-lift, short duration camshaft profiles to help boost low-end torque. Above 5000 rpm, the intake valves are operated by high-lift, long-duration camshaft profiles, for maximum high-rpm horsepower.

VTEC® lets the engine develop strong low-end torque along with exceptional high rpm power by varying valve lift and duration based on key engine parameters. To further refine powerplant operation, the TSX engine features the "intelligent" i-VTEC® system which adds Variable Timing Control™ (VTC™) to VTEC®. This provides continuously variable, computer controlled camshaft timing. In total, the TSX's i-VTEC® system provides performance, efficiency and emissions benefits by allowing the intake valve lift and valve timing to be continuously adjusted to suit the engine's operating parameters.

VARIABLE TIMING CONTROL™ (VTC™)

The TSX's intake camshaft timing is continuously adjusted to suit engine operating conditions by a system called Variable Timing Control™ (VTC™). An integral part of the TSX's i-VTEC® system, the new TSX employs revised VTC™ parameters to enhance power output, fuel economy and emissions performance with its precise control of cam timing.

Camshaft position, intake manifold pressure and engine rpm are simultaneously monitored by the powertrain control unit (PCM), which then commands a VTC™ actuator to advance or retard the intake camshaft timing. The intake camshaft is almost fully retarded at idle to deliver a more stable idle and reduced hydrocarbon (HC) emissions. As engine RPM builds, the intake camshaft is progressively advanced so the intake valves open sooner and valve overlap increases. This reduces pumping losses, which increases fuel economy and further reduces exhaust emissions due to the creation of an internal exhaust-gas recirculation effect.

CYLINDER HEAD / VALVETRAIN

The TSX cylinder head is constructed of pressure-cast aluminum alloy and features four valves per cylinder actuated by dual overhead camshafts (DOHC). The cams are driven by an automatically adjusted silent-type chain. The chain system is maintenance free and runs in an oil bath for maximum durability. The combustion chambers have large "quench" areas to promote faster flame propagation and more complete burning, thus helping to reduce carbon monoxide (CO) and hydrocarbon (HC) exhaust emissions. Larger intake and exhaust valves and revised ports contribute to improved breathing. An increase in compression ratio from 10.5 to 11.0:1 is a significant contributor to the TSX's greater torque output.

CRANKSHAFT, PISTONS, ENGINE BLOCK & OIL PAN

TSX's forged-steel crankshaft has micropolished journals to reduce friction and improve long-term durability. The die-cast lightweight aluminum cylinder block has cast-in iron cylinder liners that are made using a unique spin casting, centrifugal process. New-design pistons use special low-friction rings to reduce power loss. For maximum rigidity and minimal noise and vibration, the cylinder block is a 2-piece design that supports the five main bearings with a single cast-alloy bed-plate assembly.

PROGRAMMED FUEL INJECTION (PGM-FI)

Programmed Fuel Injection (PGM-FI) uses an array of sensors to constantly monitor a number of critical operating variables, including throttle position, intake air temperature, water temperature, ambient air pressure (altitude), air flow, air/fuel ratio, along with the position of the crankshaft and camshafts. Highly vaporized-style fuel injector nozzles reduce the typical size of fuel droplets, which improves air/fuel atomization and flame propagation inside the combustion chambers.