2012 Acura TSX - Powertrain
For 2012, the 2.4-liter DOHC i-VTEC® inline four-cylinder engine remains as the standard engine. The engine offers good acceleration while generating excellent fuel efficiency. The all-aluminum I-4 engine produces 201 hp and 172 pound-feet of torque (6MT), 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 2.4L 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, different valve timing, and intake and exhaust flow improvements. An aluminum and resin composite intake manifold reduces weight over the previous I-4's aluminum design, while better insulating the engine's incoming airflow from under-hood heat.
The use of numerous friction reducing technologies (applied to both the 2.4L I-4 and the 3.5L V-6 engines) help reduce internal operation friction which helps deliver improved efficiency.
Both the 4- and 6-cylinder engines make use of a plateau honing technique for the cylinder bores that generates a smoother surface. As a result, the piston rings achieve more consistent contact with the cylinder walls which generates improved ring-to-bore sealing along with reduced overall friction.
With the 2.4L I-4, the pistons make use of a low-tension piston ring that reduces operating friction while the 3.5L V-6 uses a redesigned ion-plated piston ring design. In addition, the outer skirts of both the 4- and 6-cylinder pistons now feature a molybdenum coating applied in a unique dot-pattern application. The result is reduced overall friction as the pistons move within the cylinder bores.
Other friction reducing items include the use of lower viscosity engine oil (0W-20 weight versus the previous 5W-20 weight oil) along with lower viscosity oil for the Sequential SportShift 5-speed automatic transmission. In addition, the 5-speed automatic fitted to the 2.4L I-4 engine makes use of a fluid warmer assembly warmer that helps improve shift quality and engine fuel economy for TSX owners who live in colder climates.
A rear-mounted exhaust system layout, close-coupled catalytic converter and advanced Programmed Fuel Injection (PGM-FI) team to help both the I-4 and V-6 engines meet EPA 2 - Bin 5 and CARB LEV II Ultra Low Emission Vehicle standards.
Beginning in 2010, the TSX was available with a transversely mounted 3.5-liter all-aluminum V-6 engine with single overhead camshaft (SOHC) cylinder heads. The V-6's 12 intake valves are actuated by Acura's acclaimed VTEC® (Variable Valve Timing and Lift Electronic Control) system. The compact and efficient V-6 engine produces 280 horsepower and 254 lbs-ft of torque. The power curve has been specially tailored to deliver strong, linear power in the rpm range used in most day-to-day driving conditions.
|2012 TSX I-4||2012 TSX V-6|
|Engine||DOHC i-VTEC® I-4||SOHC VTEC® V-6|
|Displacement||2.4-liter (2354 cc)||3.5-liter (3471 cc)|
|Horsepower @ rpm||201 at 7,000||280 at 6,200|
|Torque @ rpm (lbs-ft)||
172 at 4,300 (MT)
|254 at 5,000|
|EPA estimated mileage
|Emissions certification||EPA TIER 2 – BIN 5 and CARB
LEV II ULEV
|EPA TIER 2 – BIN 5
and CARB LEV II
*Based on 2012 EPA mileage estimates. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.
The 2012 TSX with 2.4L I-4 engine comes with a choice of two transmissions- a close-ratio 6-speed manual transmission (TSX Special Edition only) or a Sequential SportShift 5-speed automatic transmission (all TSX models). The manual gearbox has a lightweight aluminum case and multi-cone synchronizers providing a light, quick action with very short shift throws. To provide more spirited driving, the manual transmission includes performance-minded gear ratios to maximize acceleration during spirited driving.
The Sequential SportShift 5-speed automatic transmission has a straight-style shift gate with Drive and Sport positions that provide fully automatic operation. At the driver's option, the automatic transmission can be shifted manually via steering wheel mounted paddle shifters. Grade Logic and Shift Hold Control work in automatic mode to keep the transmission in the gear that is ideal for the current driving situation. Further improving performance and drivability is a revised torque converter lock-up assembly.
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.
TSX Powertrain at A Glance
- 2.4-liter, DOHC, i-VTEC® four-cylinder engine generates 201 horsepower at 7,000 rpm with 172 lb-ft of torque at 4,300-4,400 rpm (MT); 170 lb-ft of torque at 4,300-4,500 rpm (AT)
- Lightweight aluminum pistons and high-strength connecting rods
- Dual balance shafts for exceptional smoothness
- i-VTEC® "intelligent" valve-control system combines Variable Timing Control™ (VTC™) with VTEC®
- Computer-controlled Programmed Fuel Injection (PGM-FI)
- Direct ignition system
- Drive-by-Wire™ throttle system
- 100,000-mile tune-up interval*
- EPA estimated mileage: 21/29/24 mpg** (city/highway/combined, 6 MT sedan)
- EPA estimated mileage: 22/31/26 mpg** (city/highway/combined, 5 AT sedan)
- EPA estimated mileage: 22/30/25 mpg** (city/highway/combined, 5 AT wagon)
- EPA TIER 2 – BIN 5, CARB LEV II ULEV emissions standards
- 3.5-liter, SOHC, VTEC® V-6 engine generates 280 hp at 6,200 rpm and 254 lb-ft of torque at 5,000 rpm
- Variable Valve Timing and Lift Electronic Control (VTEC®)
- Dual-stage induction system with magnesium intake manifold
- Drive-by-Wire™ throttle system
- Computer-Controlled Programmed Fuel Injection (PGM-FI)
- Direct Ignition System
- Maintenance Minder™ system
- 100,000 mile tune-up intervals*
- EPA estimated mileage:19/28/23 mpg** (city/highway/combined, 5AT, sedan)
- EPA TIER 2 – BIN 5, CARB LEV II ULEV emissions standards
*Does not apply to fluid and filter changes. Exact mileage is determined by actual driving conditions.
** Based on 2012 EPA mileage estimates, reflecting new EPA fuel economy methods beginning with 2008 models. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.
The TSX's 3.5-liter V-6 engine uses an inherently smooth-running 60-degree V-angle. The engine block is constructed of lightweight die-cast aluminum and uses thin-wall iron liners that are made in a centrifugal spin-casting process that ensures high strength and low porosity. The rough outer surface of these liners makes an effective bond with the aluminum block, enhancing block stiffness and heat transfer from the cylinder liners to the block. The cylinder liners are now finish honed using a plateau honing technique that generates a much smoother surface that translates to improved ring-to-bore sealing along with reduced operating friction.
The 3.5-liter cylinder aluminum block is heat-treated for strength and has a deep-skirt design with four bolts per bearing cap (providing excellent structural support for the crankshaft), thus minimizing engine noise and vibration.
The 2.4L I-4 uses a die-cast lightweight aluminum cylinder block with cast-in iron cylinder liners that are made using a unique spin casting, centrifugal process. Like the 3.5L V-6, the inline four uses the plateau honing technique. 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-aluminum bed-plate assembly.
The 3.5-liter engine employs a robust forged-steel crankshaft for high strength and minimum weight. Forged aluminum 11.2:1 pistons are used and are cooled with oil spray directed to the underside of the piston crowns, making possible the high compression ratio. The pistons feature a MoS2 molybdenum coating applied in a unique dot-pattern application that reduces overall friction as the pistons move within the cylinder bores.
The connecting rods are steel forgings for high strength, and are crack-separated- a unique process in which the bearing caps are broken apart from the rod rather than machined separately. This process forms a lighter, stronger connecting rod with exact mating surfaces.
The four-cylinder uses a high strength forged-steel crankshaft with micropolished journals to help reduce friction and to improve long-term durability. High compression 11:1 aluminum pistons feature a MoS2 molybdenum coating and also use low-friction rings to help reduce friction.
The 3.5-liter engine has lightweight aluminum cylinder heads that are pressure cast for high accuracy and low porosity. To save weight and reduce parts count, the cylinder heads have uniquely integrated exhaust-port castings that provide optimal positioning for close-coupled catalytic converters- one on each cylinder bank. This design results in more rapid "light off" of the catalytic converters for reduced emissions during cold start-up. The cylinder heads are sealed to the block with a 3-layer shim-type head gasket.
The 2.4L I-4 cylinder head is constructed of pressure-cast aluminum 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. Large intake and exhaust valves along with high-flow ports contribute to excellent engine breathing. Additionally, a high compression ratio of 11.0:1 is a significant contributor to the TSX's torque output.
VTEC® VALVE CONTROL SYSTEM
The 3.5-liter V-6 engine uses the Variable Valve Timing and Lift Electronic Control (VTEC®) system that provides crisp throttle response, strong low-speed torque and enhanced high-rpm power. This is achieved by providing reduced intake valve lift and duration at low engine speeds for good torque, with increased valve lift and longer duration at higher speeds for optimum power. With the VTEC® system, both intake valves are controlled by a single low-speed camshaft lobe.
On the V-6, at 4,750 rpm the Powertrain Control Module (PCM) electronically triggers the opening of a spool valve that routes pressurized oil to small pistons within the intake valve rocker arms. Moved by this pressurized oil, these pistons lock together each cylinder's intake rocker arms, which then follow in unison a single high-lift, long-duration cam lobe. Intake valve lift and opening duration are adjusted according to engine speed, resulting in a broad torque curve as well as superior power at peak rpm.
The 2.4L I-4 engine features Acura's i-VTEC® "intelligent" valve control system that pairs Variable Valve Timing and Lift Electronic Control (VTEC®) with Variable Timing Control™ (VTC™). A patented VTEC® design uses three reduced-thickness aluminum rocker arms that operate a pair of valves for each cylinder. At low rpm, the intake valves follow low-lift, short duration camshaft profiles to help boost low-end torque. Above 5,000 rpm, the valves are operated by high-lift, long-duration camshaft profiles for maximum high-rpm horsepower.
To further refine the I-4's operation, the engine features an "intelligent" element that adds Variable Timing Control™ (VTC™) to VTEC® which provides continuously variable, computer controlled camshaft timing. In total, the I-4'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™)
With the 2.4-liter engine, intake camshaft timing is continuously adjusted to suit engine operating conditions via a system called Variable Timing Control™ (VTC™). An integral part of the i-VTEC® system, the VTC™ enhances power output, fuel efficiency and emissions performance with its precise control of camshaft 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 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. Such operation reduces pumping losses, which increases fuel efficiency and further reduces exhaust emissions due to the creation of an internal exhaust-gas recirculation effect.
The 3.5L V-6 features a dual-stage intake manifold made from lightweight magnesium. The manifold works together with VTEC® to improve low-speed torque with no sacrifice in high-rpm power. Divided into two banks feeding three cylinders per bank, the manifold has two Powertrain Control Module-controlled valves located between each bank. These valves are closed at low engine speed, which reduces the operating volume of the plenum and increases the effective length of the inlet passages. The result is maximum resonance effect and amplification of pressure waves within each half of the manifold at lower engine speeds, significantly increasing cylinder filling and low rpm torque. The open ends of the intake runners are also flared into a "trumpet" shape (as on racing engines) to further improve airflow.
At 3,950 rpm the valves open, connecting the two halves of the manifold, increasing its effective volume and increasing the mass of air rushing down each intake passage. The inertia of this increased air mass forces more charge into each cylinder for better cylinder filling, increasing power at high rpm. The manifold's two modes further complement the changes in low and high speed running made possible by the VTEC® system.
The induction system used with the 2.4L I-4 is designed for high flow as well as to create an aggressive sound. The inlet design allows cool ambient air to be picked up at the front of the vehicle, and then routed though a high-flow air filter assembly. The single-stage lightweight plastic intake manifold has fixed-length intake runners that are tuned in length, diameter and shape to provide an optimal blend of low-rpm torque and high-rpm response. The composite manifold incorporates 48 mm intake runners along with a high flow aluminum throttle-body.
PROGRAMMED FUEL INJECTION (PGM-FI)
Both the I-4 and V-6 engines feature Programmed Fuel Injection (PGM-FI) that 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 injectors reduce the typical size of fuel droplets, which improves air/fuel atomization and flame propagation inside the combustion chambers.
MULTI-HOLE FUEL INJECTORS
Special multi-hole fuel injectors mounted in the lower intake manifold spray directly toward the intake ports. The multi-hole injector design means that fuel droplet size is reduced for better fuel atomization, resulting in improved cold weather start-up, better fuel efficiency and higher horsepower.
DRIVE-BY-WIRE™ THROTTLE SYSTEM
In place of a conventional mechanical throttle linkage setup, the TSX uses a Drive-by-Wire™ throttle system. The result is more accurate and precise throttle control, along with reduced weight and less clutter under the hood. A DC motor controls the amount of throttle-body opening that leads to the intake manifold. This allows the ratio between pedal movement and throttle motion to be altered to suit the specific driving conditions. The system monitors throttle pedal position, throttle-body opening amount, road speed, engine speed (rpm) and engine vacuum. This information is used to define the throttle control sensitivity. The system also alters throttle response based on the calculated road slope, providing more throttle gain uphill and less downhill. When driving on curvy roads, the Drive-by-Wire™ throttle system recalibrates throttle gain to make the TSX easier to control.
In addition, the Drive-by-Wire™ throttle system works with the Sequential SportShift 5-speed automatic transmission to make gear shifts smooth and quick. With coordination of the throttle opening and the transmission's shifting functions, shift shock and shift delay are reduced.
ONE-TOUCH STARTER SYSTEM (TSX V-6)
A TSX fit with the available 3.5-liter V-6 features a starter with more power to crank the larger engine. In addition, the TSX V-6 has a one-touch starter system that automatically maintains starter engagement until the engine has started. The TSX driver simply activates the starter switch once by turning the key and needs not hold the switch in the Start position. Once the V-6 engine starts, the one-touch system disengages the starter automatically.
The TSX 3.5-liter V-6 has exhaust manifolds that are cast directly into the cylinder heads for reduced weight, parts count and bulk. Attached directly to the cylinder heads are high-efficiency catalytic converters. Due to closer-than-normal proximity to the exhaust ports, the close-coupled catalytic converters "light off" very quickly after the engine starts, reducing emissions during the critical start-up mode. To ensure optimum flow and low backpressure, a hydroformed two-into-one collector connects the close-coupled catalytic converters to the main under-floor catalytic converter.
Downstream of the under-floor converter, the V-6 engine has a single pipe that feeds to a pair of resonators, followed by a pipe split that connect to a pair of high-flow mufflers fit with round exhaust tips. With the V-6, the exhaust system is tuned to deliver a sportier, more aggressive exhaust note than with the 2.4L I-4.
To help boost engine torque, the 2.4L I-4 has a high-flow, low back-pressure exhaust system. Large-diameter pipe sizes throughout the exhaust system increase flow; beyond the under-floor catalytic converter, the exhaust system passes through a pre-chamber (located under the second-row floorboards), and then splits just behind the rear axle to feed into free-flowing dual silencers fitted with chrome exhaust tips.
The 2012 TSX is compliant with the California Air Resources Board (CARB) LEV II ULEV standard, which is one of the toughest emissions regulations in the United States. The TSX also achieves EPA TIER 2 - BIN 5 regulations emissions compliance.
Acura's advanced technologies contributing to this performance are the close-coupled catalytic converters which light-off quickly on start-up, an increased amount of EGR gas recirculated into the engine, and an advanced 32-bit RISC microprocessor within the Powertrain Control Module (PCM) that boosts computing power to improve the precision of fuel and spark delivery at all engine speeds and conditions. Particularly in the critical post-startup mode, the high-efficiency multi-hole fuel injectors deliver better fuel atomization for lower emissions.
Both TSX engines feature Programmed Fuel Injection (PGM-FI) that continually adjusts fuel delivery to achieve the best combination of power, fuel efficiency, and low emissions. The fuel injectors help reduce exhaust hydrocarbons after engine startup, while a linear air/fuel sensor positioned in the exhaust system just upstream of the catalyst improves air/fuel mixture control.
The inline four-cylinder engine is designed with emissions performance in mind, employing Variable Timing Control™ (VTC™) and a unique i-VTEC® cylinder head design promoting exceptional internal exhaust gas recirculation, which helps reduce NOx emissions output.
Both the V-6 and I-4 engines feature an exhaust manifold design that is integrated directly into the cylinder head casting. This unique design allows the catalytic converter to be positioned very close to the cylinders for swift converter light-off after a cold engine start. A secondary catalytic converter is positioned downstream under the passenger compartment floor.
DIRECT IGNITION AND DETONATION-KNOCK CONTROL
A strong ignition spark is critical to improve power and reduce emissions. Thus, both the 2.4L I-4 and 3.5L V-6 engines feature a direct ignition system that uses individual coil units positioned directly above each spark plug. Because accurate ignition spark timing is crucial for best power and torque output (as well as reduced emissions), the Powertrain Control Module (PCM) continually monitors several engine parameters to determine optimum spark timing based on specific driving conditions.
Additionally, a block-mounted acoustic detonation (knock) sensor "listens" to the engine, sending information about potentially damaging detonation to the PCM, which then incrementally retards ignition timing as needed to help prevent damage.
NOISE, VIBRATION & HARSHNESS (NVH) CONTROL
The 3.5L V-6 is designed to effectively control noise, vibration and harshness (NVH). Featuring a high-rigidity die-cast engine block with 60-degree V-angle cylinders, a strong forged-steel crankshaft, die-cast accessory mounts and stiff cast aluminum engine oil pan, low engine NVH is ensured. The induction and exhaust systems are designed to emit a refined and quiet tone at low speeds, with a sporty "growl" above 3,000 rpm.
The 2.4L I-4 engine has an array of features designed to reduce NVH. The pressure-cast cylinder block has a bed-plate type main bearing cap that results in a highly rigid assembly, which helps to resist vibration. Two balance shafts further smooth the inherent vibration commonly found with a large-displacement inline four-cylinder engine layout. A self-adjusting, silent-type camshaft drive chain and serpentine accessory drive belt team to help reduce NVH.
ELECTRONIC CONTROL MOUNT (ECM)
Acura's sophisticated Electronic Control Mount (ECM) system is used to minimize the effects of engine vibration. At low engine speeds, vacuum-controlled engine mounts allow additional engine movement, so that less low-frequency vibration is transmitted to the body. At higher rpm, the ECM mounts stiffen so that the mass of the engine is properly restrained for better handling.
With the 3.5L V-6, in addition to being used for the engine, ECM mounts are also used for the Sequential SportShift 5-speed automatic transmission.
ENGINE COMPARTMENT COVER
While the engine compartments for both TSX models are handsomely finished, the 3.5L V-6 features an engine compartment cover that conceals accessory systems. The engine itself is visible and is finished to eliminate the need for traditional cosmetic covers. Whereas the 2.4L I-4 TSX uses a prop rod to hold open the hood, the 3.5L V-6 TSX makes use of a gas-charged strut assembly to hold open the hood. The strut setup not only delivers an improved underhood appearance, but it helps lift the hood during opening as a convenience to the user.
100,000 MILE TUNE-UP INTERVAL
All TSX models are exceptionally low-maintenance automobiles. With features like Iridium alloy-tipped spark plugs and a space-saving, self-tensioning serpentine accessory drive belt assembly, both TSX engines require no scheduled maintenance until 100,000 miles (exclusive of periodic inspections and normal replacement of fluids and filters). The first scheduled service at 100,000 miles includes valve adjustment, timing belt replacement and water-pump inspection. Note that 100,000-mile tune-up interval does not apply to fluid and filter changes. Exact mileage is determined by actual driving conditions.
MAINTENANCE MINDER™ SYSTEM
All TSX models feature as standard equipment a Maintenance Minder™ system automatically monitors the vehicle's operating condition. The driver is alerted via a message on the Multi-Information Display (MID) when maintenance is required. The system helps eliminate unnecessary service stops, while ensuring that the vehicle is properly maintained.
The Maintenance Minder™ system monitors operating conditions such as coolant and oil temperatures along with engine speed, and then determines the proper service intervals. Depending on the engine operating conditions, oil change intervals can be extended to a maximum of 10,000 miles, potentially sparing the owner considerable money and inconvenience over the life of the vehicle.
The Multi-Information Display (MID) shows the remaining percentage of engine oil life, and indicates when service is due via a wrench icon. A percentage-based countdown to the next service is displayed when the car is within 15-percent of the end of the service interval. The type of service required is shown in an alphanumeric code, and if a service is missed, the MID indicates its urgency by showing past-due mileage. The system can be reset manually by the owner, and monitors all normal service parts and systems, including oil and filter, air-cleaner, tire rotation, automatic transmission fluid, coolant, spark plugs, timing belt, brake pads and more. Maintenance alerts are presented on the instrument cluster when the ignition is first turned on, and not while driving.
SEQUENTIAL SPORTSHIFT 5-SPEED AUTOMATIC TRANSMISSION
All TSX models are available with a smooth shifting Sequential SportShift 5-speed automatic transmission. Although similar in design, the transmission fit to the V-6 engine is more robust to handle the substantial increase in horsepower. In addition, the transmission uses special gear ratios to take advantage of the V-6's abundant torque. Although the I-4 and V-6 use different transmission gear ratios, the operation of the Sequential SportShift 5-speed automatic transmission is identical. Both Sequential SportShift 5-speed automatic transmissions feature racing-inspired paddle shifters (mounted on the backside of the steering wheel) and Grade Logic Control to maximize acceleration, fuel efficiency and driver control.
A console mounted, 5-position shift gate makes operation of the transmission simple. When in the "D" position, the transmission operates automatically (selecting from one of the five forward gears) based on the driving conditions. When in automatic mode, the transmission incorporates advanced Grade Logic Control and Shift Hold Control, both of which work to reduce gear "hunting" on hills or when the TSX is in the midst of a turn.
Grade Logic Control reduces shift frequency and improves vehicle speed control by altering the transmission's shift schedule when traveling uphill or downhill. The transmission computer continuously compares throttle position, vehicle speed and acceleration/deceleration with a map stored in the computer memory. The Grade Logic Control System determines when the TSX is on an upslope or down slope. The shift schedule is then adjusted to automatically hold the transmission in a lower gear for better climbing power or increased downhill engine braking.
When the throttle is quickly released and the brakes are applied, as might be the case when decelerating for a corner, Shift Hold Control keeps the transmission in its current (lower) gear ratio. This helps provide added engine braking, and ensures that abundant power is immediately available at the corner exit.
The TSX is equipped with paddle shifters (mounted to the back side of the steering wheel) that operate the Sequential SportShift 5-speed automatic transmission. The paddle shifters are activated with a fingertip pull; the right paddle commands an upshift while a pull of the left paddle commands a downshift. A digital display in the tachometer face indicates which gear the transmission is in when the steering wheel paddles are active.
The steering wheel paddles can operate in both the "D" and "S" transmission positions. When in "D," a touch of a paddle shifter temporarily places the transmission in manual mode (but without gear holding at redline). After steady-state cruising conditions are detected, the transmission returns to fully automatic operation. In "S," engaging a paddle shift enables transmission gear holding, which allows only driver-commanded shifts, with the exception of automatically shifting to First gear at a stop- even if not driver-selected.
When first placed in "S" mode, the transmission will automatically shift between First, Second, Third and Fourth gears until a paddle shifter is activated. When a paddle shifter is activated, the transmission goes into full manual mode and upshifts will only be made if commanded by the driver.
Manual mode protective features
To help protect the engine and drivetrain from damage, an array of protective features are active when the transmission is in manual mode. The Powertrain Control Module (PCM) will cut fuel flow to the engine if there is a possibility of over-revving in a specific gear, as might occur if the driver is late in commanding an upshift. To prevent over-revving while downshifting, the transmission will not execute a driver-commanded downshift that would send the engine beyond redline in the lower gear. Even if the driver allows the vehicle to come to a stop in a high gear, the transmission will automatically downshift to First gear to prevent lugging away from a stop in a high gear.
|5-Speed Automatic Transmission Gear Ratio Comparison|
|5AT (I-4 engine)||5AT (V-6 engine)|
Cooperation between Automatic Transmission & Drive-by-Wire™ Throttle System
With the TSX's electronically-controlled Sequential SportShift automatic transmission and Drive-by-Wire™ throttle system, the function of the engine and transmission are closely choreographed for faster, smoother shifting. As a result, shift shock is reduced significantly during shifts.
ACTIVE LOCK-UP TORQUE CONVERTER
To provide good fuel efficiency while maintaining a high level of drivability, the 5-speed automatic transmission includes an active lock-up torque converter. With the precise control afforded by a linear solenoid and assist spring, the system features a wide range of speed and throttle settings in which lock-up assembly can be engaged in the four forward gears. This results in improved fuel efficiency for both city and highway driving.
6-SPEED MANUAL TRANSMISSION
Available with the TSX Special Edition with 2.4L I-4 is a close-ratio 6-speed manual transmission. With precise and light shifting action, the manual gearbox is designed to compliment the TSX's sporting side. Compared to a 5-speed transmission, the 6-speed gearbox allows for closer gear ratio spacing. Such tighter gear spacing enables the engine to operate closer to its power peak during acceleration for better performance.
The compact, highly rigid transmission case is cast of aluminum to reduce weight. Additionally, the highly rigid casting helps damp out noise and vibration. Multi-cone synchronizers on First through Fourth gears reduce and smooth shifting effort. A high (numerically low) top gear ratio allows for a relaxed cruising rpm, improved fuel efficiency and lower emissions.
The close-ratio 6-speed manual transmission teams with a specially designed clutch pedal assembly that delivers low-effort actuation and has a broad engagement band for progressive engagement and smoother launches.