The 2013 RDX makes use of a 3.5-liter SOHC V-6 engine that marks the first-ever application of a V-6 in the model. Replacing the previous turbocharged 2.3L inline four cylinder engine, the naturally-aspirated V-6 offers significantly more horsepower and improved fuel economy- while simultaneously offering a more refined feel. Producing 273 horsepower, the V-6 engine makes 33 more horsepower than the previous 2.3L turbocharged engine.
The all-aluminum 3.5-liter V-6 uses single overhead camshaft (SOHC) cylinder heads fitted with 24 valves- with the valves actuated by intelligent Variable Valve Timing and Lift Electronic Control® (iVTEC®). The V-6 engine also debuts numerous power and fuel efficiency technologies that have never been applied to an Acura vehicle. Of great interest is use of Variable Cylinder Management™ (a first-ever application for Acura) that helps improve fuel efficiency as it allows the V-6 engine to run on six, four, or three cylinders based on driving conditions. Another new technology to debut for Acura is a unique Overrunning Alternator Decoupler (OAD) system that helps absorb dynamic variations in drive belt tension. Thanks to the OAD, belt tension can by reduced by approximately 30-percent which reduces engine friction losses for better power output and reduced fuel consumption.
The 3.5L V-6 engine reflects Acura’s unwavering commitment to the environment with good fuel efficiency and full compliance with EPA TIER 2 – BIN 5 and CARB LEV II ULEV emissions standards.
The V-6 engine teams with a new Sequential SportShift 6-speed automatic transmission along with a special multi-clutch lock-up torque converter. With comparatively “short” gearing in the first five forward gears, acceleration is enhanced while relaxed cruising is optimized thanks to a tall Sixth gear ratio. The new 6-speed transmission offers two automatic shift modes, or can be operated manually via racing-inspired paddle shifters mounted on the backside of the steering wheel. Grade Logic Control, Shift Hold Control and Cornering G Shift Control help make the 6-speed the most advanced automatic transmission ever offered by Acura.
Powertrain at a Glance
2013 Acura RDX
- Front-wheel-drive or available AWD with Intelligent Control
- 3.5-liter, SOHC, aluminum V-6 engine
- 273 hp at 6,200 rpm and 251 lbs-ft of torque at 5,000 rpm
- 10.5:1 compression ratio
- Variable Cylinder Management™ with Intelligent Variable Valve Timing and Lift Electronic Control (iVTEC®) for intake and exhaust valves
- Lightweight magnesium intake manifold
- Computer-controlled Programmed Fuel Injection (PGM-FI)
- Drive-by-Wire™ throttle system
- Cold-air intake system
- Direct ignition system
- Detonation/knock-control system
- 100,000 mile tune-up intervals*
*Does not apply to fluid and filter changes. Exact mileage is determined by actual driving conditions.
- High-flow close-coupled catalytic converters plus under-floor catalytic converter
- High-capacity 32-bit RISC processor electronic control unit
- Meets EPA TIER 2 – BIN 5 and CARB LEV II ULEV emissions standards
- RDX: EPA estimated* 20/28/23 mpg (city/highway/combined)
- Best-in-class Fuel Economy (RDX with front wheel drive)
- RDX with AWD with Intelligent Control: EPA estimated* 19/27/22 mpg (city/highway/combined)
*Based on 2013 EPA mileage estimates. Use for comparison purposes only. Your actual mileage will vary depending on how you drive and maintain your vehicle.
Noise, Vibration, and Harshness (NVH) control
- 60-degree cylinder V-angle for smooth running
- Automatically tensioned, maintenance-free serpentine accessory belt drive
- Electric Power Steering (EPS) eliminates hydraulic pump noise and vibration
- Electronically controlled hydraulic engine mounts reduce vibration
Sequential SportShift 6-speed automatic transmission
- Quick-response Sequential SportShift allows for semi-manual operation
- Straight-gate style console-mounted shifter
- Racing-inspired, steering-wheel-mounted paddle shifters
- Coordination between Drive-by-Wire™ throttle system and Sequential SportShift transmission makes for quick, smooth shifts
- Advanced Shift Hold Control minimizes unwanted shifting during spirited driving
- Grade Logic Control System reduces gear hunting when climbing hill
The RDX’s 3.5-liter V-6 engine uses an inherently smooth-running 60-degree V-angle. The cylinder block is constructed of aluminum and has cast-in iron cylinder liners. The cylinder heads are cast of lightweight aluminum and feature four valves per cylinder. A 10.5:1 compression ratio, high-output port shapes, intake airflow enhancements and a sport-tuned exhaust system team to enhance power. In addition to a high specific power output, the 3.5-liter V-6 delivers exceptional refinement and low emissions.
The 3.5-liter engine block is constructed of lightweight die-cast aluminum. The V-6 engine has thin-wall iron cylinder 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 for an effective bond with the aluminum block, generating good block stiffness and heat transfer from the liners to the block.
The 3.5L cylinder 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 helping to minimize engine noise and vibration.
The 3.5-liter V-6 engine uses a robust forged-steel crankshaft for high strength and minimum weight. Forged aluminum pistons are used and are cooled with oil spray directed up to the underside of the piston crowns, making possible the high 10.5:1 compression ratio. The connecting rods are steel forgings for high strength, and are “crack separated”- a unique process in which the bearing caps are broken away from the rod rather than machined separately. This process forms a lighter, stronger connecting rod with perfect mating surfaces.
The 3.5L V-6 uses 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 integrated exhaust-port castings that provide optimal positioning for close-coupled catalytic converters- one located on each cylinder bank. This design results in more rapid “light off” of the catalytic converters during cold start-up for reduced emissions. The cylinder heads are sealed against the block with a special 3-layer shim-type head gasket.
VARIABLE CYLINDER MANAGEMENT™ (VCM®) WITH iVTEC®
In a first-ever application for an Acura engine, Variable Cylinder Management™ (VCM®) is applied to the 2013 RDX 3.5L V-6 engine to help improve the fuel efficiency. Known as VCM-II, it is the latest version of the system that allows the engine to run in one of three operating parameters- all six cylinders, four cylinders or three cylinders. The original version of VCM® (used on earlier Honda V-6 engines) only allowed for six- or three-cylinder operation.
With the VCM® system, during cold start-up or whenever high power is required (such as during acceleration) all six cylinders function as normal. However, during moderate throttle applications, the VCM® system allows the V-6 engine to operate on four cylinders to save fuel. During light throttle applications, VCM® switches the engine to three cylinder operation to maximize fuel economy. During VCM® activation, cylinders three and four are deactivated when running in four-cylinder mode. When in three-cylinder mode, cylinders one, two and three are deactivated.
Working in concert with the Intelligent Variable Valve Timing and Lift Electronic Control (iVTEC®) system, the Powertrain Control Module (PCM) electronically triggers the opening/closing of spool valves (integrated within the cylinder heads) that regulate valve lift. Based on commands from the PCM, valve lift occurs when the spool valves direct oil pressure to the rocker arms for specific cylinders. During Variable Cylinder Management™ activation, the spool valves reroute the oil which results in no valve opening for a particular cylinder.
With the VCM® system, for the cylinders not being used, both the intake and exhaust valves remain closed. In addition, the fuel injectors for the inactive cylinders are not fired during VCM® operation. However, during engine operation the spark plugs continue to fire for the inactive cylinders to minimize plug temperature loss as well as to prevent fouling that could occur as a result of incomplete combustion during cylinder re-activation.
During operation, VCM® monitors a wide variety of engine parameters including vehicle speed, engine speed (rpm), throttle position, engine load, transmission gear and other factors to determine the proper amount of cylinder activation required. To ensure smooth engine operation during the transition between cylinder activation/deactivation, VCM® adjusts items such as ignition timing, throttle position as well as determines if torque converter lock-up is required. As a result, the transition between six-, four-, or three-cylinder operation is virtually unnoticeable to the driver.
DRIVE-BY-WIRE™ THROTTLE SYSTEM
The 2013 RDX does not use conventional mechanical throttle linkage, but instead employs sophisticated electronics to provide the connection between the throttle pedal and the engine’s throttle-body. The result is more accurate and precise throttle control, along with less clutter and reduced weight under the hood. By programming such factors as “gain” and “tip-in” into the throttle actuation, engine response and drivability can be tailored to suit specific driving conditions.
Acura’s Drive-by-Wire™ throttle system monitors pedal position, amount of throttle-body opening, engine rpm and road speed to establish driving conditions in real time. This data is used to define the throttle control sensitivity necessary to provide a predictable and responsive feel corresponding to driver expectations.
The Drive-by-Wire™ throttle system also helps integrate engine functions with the Vehicle Stability Assist™ (VSA®) and traction control systems. To smooth downshifts, when the Sequential SportShift transmission is in Sport mode the system is programmed to “blip” the throttle to help match engine speed to gear speed within the transmission.
PROGRAMMED FUEL INJECTION (PGM-FI)
The Programmed Fuel Injection (PGM-FI) system continuously tracks many engine parameters including crankshaft and camshaft positions, throttle position, intake air temperature and mass flow rate, engine coolant temperature, and manifold pressure- and then the PGM-FI system adjusts fuel delivery accordingly to deliver the best combination of power, fuel economy and low emissions.
MULTI-HOLE FUEL INJECTORS
Special multi-hole fuel injectors mounted in the lower portion of the intake manifold spray directly toward the intake ports. The multi-hole injector design enables the reduction in fuel droplet size to generate better fuel atomization, resulting in improved cold weather start-up, better fuel economy, reduced emissions and improved power.
DIRECT IGNITION AND DETONATION-KNOCK CONTROL
Because accurate spark timing is crucial for best power output as well as reduced emissions, the Powertrain Control Module (PCM) continually monitors several engine parameters to determine optimum spark timing for varying conditions. Additionally, a cylinder-block-mounted acoustic detonation (knock) sensor “listens” to the engine, sending information about potentially damaging detonation to the PCM, which then can retard ignition timing to help prevent damage. The ignition system uses coil units positioned directly above the iridium alloy-tipped spark plugs, which require no scheduled service prior to 100,000 miles of use.
HIGH-FLOW EXHAUST SYSTEM WITH CLOSE-COUPLED CATALYTIC CONVERTERS
The 3.5L V-6 engine features 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 engine start-up which helps reduce emissions in the critical cold-start mode.
Downstream, an under-floor catalytic converter is used that connects to a pair of resonators, and a large muffler with dual outlet exhaust tips that are hidden under the rear body fascia.
In an effort to be more ecologically friendly, the catalytic converters on the 2013 RDX use about 30-percent less precious metals (such as platinum, palladium and rhodium) than the previous design catalytic converters.
The 3.5L V-6 engine meets EPA TIER 2 – BIN 5 and CARB LEV II ULEV emission standards, and is certified to this stringent standard for 120,000 miles of service.
Contributing to this performance are 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 during varying engine speeds.
Also helping with emissions control is the Programmed Fuel Injection (PGM-FI) system that continually adjusts fuel delivery to achieve the best power, fuel efficiency and low emissions. Particularly important during the critical post-startup mode, the high-efficiency multi-hole fuel injectors help deliver better fuel atomization for lower emissions.
ONE-TOUCH STARTER SYSTEM WITH HIGH-POWERED STARTER
For 2013, the RDX receives Acura’s Keyless Access System that incorporates pushbutton start that does not require the use of a key to start the engine. Rather, the driver pushes a dash-mounted START/STOP button to control the engine. With the new pushbutton start, the RDX driver need only engage the brake, depress the starter button once (no need to hold the button down) and then the system will start the engine and disengage the starter automatically.
ENERGY MANAGEMENT SYSTEM (EMS)
The RDX has a new Energy Management System (EMS) that is designed to reduce the chance of a dead battery, increase the overall service life of the battery and help deliver improved fuel economy.
Should a RDX owner accidentally leave on the headlights or not close a door causing an interior light to remain on, after a set period of time the EMS will automatically terminate power delivery to prevent the battery from going dead.
The RDX 3.5L engine makes use of a powerful 130 amp alternator that charges in five different ranges- 12.5-, 13.0-, 13.5-, 14.0-, and 14.5-volts. By closely controlling the alternator charge voltage, EMS works to keep the battery in a specific charge range which can extend the service life of the battery by more than 25 percent. With EMS keeping the battery in a specific charge range, the alternator can run more often in the low range which generates less drag on the engine resulting in improved fuel economy.
Application of numerous electrical power reducing items allows the EMS to operate the alternator even more frequently in the more efficient low charge mode.
Should a battery or charging system issue occur, the Multi Information Display (MID) will alert the driver with a text prompt such as, “CHECK CHARGING SYSTEM”.
OVERRUNNING ALTERNATOR DECOUPLER (OAD)
Marking its first ever use by Acura, the 2013 RDX features a new Overrunning Alternator Decoupler (OAD) that helps to better absorb dynamic variations in belt tension, contributing to a more stable operation. As a result of OAD, nominal belt tension can thus be reduced by approximately 30 percent, helping reduce engine friction losses for improved fuel efficiency.
NOISE, VIBRATION AND HARSHNESS (NVH) CONTROL
The V-6 engine in the 2013 RDX is designed to effectively control Noise, Vibration and Harshness (NVH). A high-rigidity die-cast engine block, 60-degree cylinder V-angle, a strong forged-steel crankshaft, a stiff cast aluminum engine oil pan and die-cast accessory mounts team to reduce engine NVH. For 2013, the RDX uses a new floating-style front subframe assembly helps improve NVH.
An Active Control Engine Mount system (ACM) is used to minimize the effects of engine vibration as the VCM® system switches cylinders on and off. Sensors alert the Electronic Control Unit (ECU) to direct ACM actuators positioned at the front and rear of the engine to move to cancel engine vibration.
100,000 MILE TUNE-UP INTERVAL
The 2013 RDX is engineered to be an exceptionally low-maintenance vehicle. With features like iridium alloy-tipped spark plugs and a self-tensioning serpentine accessory drive belt, the 3.5L V-6 engine requires no scheduled maintenance until 100,000 miles* of use- with the exception of periodic inspections and normal replacement of fluids and filters. The first scheduled service at 100,000 miles includes items such as valve adjustment, timing belt replacement and water-pump inspection.
*Exact mileage is determined by actual driving conditions.
The 2013 RDX has as standard equipment a Maintenance Minder™ system that monitors operating conditions and alerts the driver should maintenance be required. When the ignition is first turned on, the Multi-Information Display (located between the tachometer and speedometer) shows maintenance information, if required.
To avoid distraction, the display is not shown while driving. In addition, the MID identifies the remaining engine oil life percentage and a wrench icon illuminates when service is due. 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 owner-resettable Maintenance Minder™ system monitors the service life of normal service parts and systems including oil, oil filter, tire rotation, air cleaner, automatic transmission fluid, spark plugs, timing belt, and coolant. In addition, Maintenance Minder™ is designed to eliminate unnecessary maintenance, reduce environmental impact and expenses, and help ensure long component and vehicle life.
SEQUENTIAL SPORTSHIFT 6-SPEED AUTOMATIC TRANSMISSION
To improve acceleration, passing ability and fuel economy, the 2013 RDX uses a new Sequential SportShift 6-speed automatic transmission- a first ever use of a 6-speed in an RDX. Careful engineering of the layout and power flow of the new 6-speed minimizes exterior size, parts count and overall weight compared to the previous RDX’s 5-speed automatic transmission.
The new 6-speed has lower gear ratios (higher numerically) in First through Fifth gears and in Reverse compared to the previous 5-speed. The lower gear ratios improve acceleration and pulling power. The Sixth gear ratio is tall (just as with the top gear in the previous 5-speed automatic transmission) which generates a more relaxed cruising rpm and enhanced highway fuel economy.
The 6-speed automatic transmission also includes engineering enhancements aimed at improved performance and fuel economy. Expanded control of the multi-disc lock-up assembly within the torque converter improves the efficiency of power delivery and works with the new gear ratios to provide an improvement in city/highway/combined fuel economy (+1/+4/+2 mpg for 2WD; +2/+5/+3 mpg for AWD).
The 6-speed transmission can be controlled by a console-mounted straight-gate shifter or via a steering wheel paddle shifter system that works whenever the transmission is in either of its two automatic modes. In addition to Grade Logic Control and Shift Hold control, the 6-speed also has Cornering G Shift Control. All of the transmission logic systems work together to automatically alter shift timing based on driving conditions.
The Sequential SportShift 6-speed transmission can be operated in two different fully automatic modes via the console-mounted straight-gate shifter. The D (or “Drive”) mode is ideal for most driving situations, and combines fuel efficiency with smooth operation and responsive power when needed. The S (or “Sport”) mode is for more performance-oriented driving, and features more aggressive shift mapping to keep engine rpm higher for greater acceleration and response.
In Sport mode the transmission typically operates in the four lowest gears, and won’t shift to Fifth gear unless the vehicle reaches a higher speed. In Sport mode, the economy-oriented Sixth gear is locked out.
When in the D mode (that is optimized for normal driving), the transmission incorporates an advanced Grade Logic Control System, Shift Hold Control and Cornering G Shift Control- all of which reduce unwanted shifting and gear hunting. The result is smart transmission operation that optimizes fuel efficiency and keeps the transmission in the appropriate gear for the specific driving conditions, thus generating excellent performance and smooth operation.
While traveling up or down hills, Grade Logic Control alters the transmission’s shift schedule to reduce shift frequency and improve speed control. A shift map in the transmission computer continually measures throttle position, vehicle speed and acceleration/deceleration, and then determines when the vehicle is on a hill. The shift schedule is then adjusted to hold the transmission in lower gears to boost climbing power or to provide engine braking when traveling downhill.
Shift Hold Control keeps the transmission in its current (lower) gear ratio when aggressive driving is detected, as in the case of decelerating at a corner entry. Shift Hold Control leaves the chassis undisturbed (as caused by excess shifting) and ensures that power will be immediately available at the corner exit without the need for a downshift.
Cornering G Shift Control is a transmission feature that debuted on the Sequential SportShift 5-speed automatic transmission. Cornering G Shift Control monitors the speed of each rear wheel independently to determine when the RDX is turning. When the system detects a sufficient speed differential between the rear wheels, it will suppress an unwanted upshift. This prevents the transmission from upshifting during a corner, which could upset the chassis balance and would then require downshifting again at the corner exit as the throttle is applied.
Temporary Manual Operation in “Drive”
Whether in Drive or Sport mode, special transmission programming allows the use of the steering-wheel-mounted paddle shifters. When the driver operates the paddle shifters while in Drive, the transmission responds to the driver’s shift command and then returns to its normal fully automatic Drive mode if further paddle shift inputs are not made within a short time. This special logic makes it easy for the driver to command a quick downshift without leaving the comfort of Drive mode. When in Sport mode, use of the paddle shifters puts the transmission into full manual mode that remains active until another mode of operation is selected with the console-mounted shifter.
By moving the center console-mounted gear selector lever rearward to the detent labeled “S,” the transmission is shifted into Sport mode. This mode offers automatic operation with more aggressive shift mapping. A pull on the racing-inspired paddle shifters (mounted on the steering wheel) places the transmission in fully manual mode. A digital display in the tachometer face indicates which gear the transmission is in.
A unique double-kick-down feature lets the driver command a sport-minded double downshift- such as from Fifth to Third gear. By pulling on the left downshift paddle twice in rapid succession, the transmission will drop directly to the chosen lower gear ratio. The Drive-by-Wire™ throttle system also creates a “blip” of the throttle to help match gear speeds while downshifting.
To prevent harm to the powertrain when the transmission is paddle shifted by the driver (including during double-kick-down shifts), the system will inhibit potentially damaging shifts. As an added safety measure, the Powertrain Control Module (PCM) can also cut off engine fuel flow to prevent over-revving. If fuel cut-off is insufficient to prevent engine over-revving, as may be possible when the vehicle is on a steep downhill, the transmission will automatically upshift to prevent damage. On downshifts, the transmission will not execute a driver command that will over-rev the engine.
For improved stop-and-go performance and to prevent “lugging” the engine, the Sequential SportShift transmission will automatically downshift to First gear even though the transmission has been left in a higher gear, as the vehicle comes to a stop. In Manual Mode, when coming to a stop in Second gear, the vehicle will start in Second gear as well.
MULTI-CLUTCH LOCK-UP TORQUE CONVERTER
The Sequential SportShift 6-speed automatic transmission teams with a special torque converter that not only has a higher maximum torque rating, but also has a unique converter lock-up assembly. The lock-up assembly uses multiple lock-up disks that generate nearly double the facing area of a typical torque converter.
The lock-up assembly not only reduces heat build-up during operation, but also features improved overall lubrication that generates better cooling. The torque converter allows for lock-up activation during a much wider range of driving conditions that helps improve fuel economy.
COOPERATION BETWEEN TRANSMISSION AND DRIVE-BY-WIRE™ THROTTLE SYSTEM
Shift speed and smoothness are enhanced as a result of cooperation between the Drive-by-Wire™ throttle system and the electronically controlled Sequential SportShift transmission. During upshifts and downshifts, the engine can be throttled by the engine management system, reducing peak forces (shift shock) on transmission components, thus improving component reliability and decreasing driveline harshness. With the new Sequential SportShift 6-speed transmission, the Drive-by-Wire™ throttle system also creates a “blip” of the throttle to help match gear speeds while downshifting.
AWD WITH INTELLEGENT CONTROL
The 2013 RDX uses an all-new all-wheel-drive system that is lighter, more compact and more efficient than previous all-wheel-drive system. Known as AWD with Intelligent Control, the new system introduces a high degree of four-wheel-drive sophistication on paved and dirt roads as well as in inclement conditions such as rain or snow. Operation of the new AWD is completely automatic and is nearly transparent to the driver. Unlike some four-wheel-drive systems that require the driver to select a drive mode based on the perceived need, AWD with Intelligent Control operates automatically based on specific road conditions which allows the driver to focus more on driving when situations are demanding.
The capabilities of the new AWD system are prioritized to support high fuel efficiency and all-around good drivability. AWD with Intelligent Control can operate at all speeds when needed, but when torque transfer to the rear wheels is not required (such as when cruising), drive to the rear wheels is decoupled for reduced drag. However, when accelerating from a stop, AWD with Intelligent Control sends power to the rear wheels while constantly communicating with Vehicle Stability Assist (VSA) and the new Motion-Adaptive Electric Power Steering (EPS) to detect any traction issues.
The major components of the new AWD system consist of a conventional front-wheel-drive system, a compact transfer case that distributes torque to a driveshaft running the length of the vehicle, a rear differential, a new electronically-controlled hydraulic pump, a multi-plate clutch, and left and right rear axles.
For AWD with Intelligent Control, a multi-plate clutch (similar to the clutches used in an automatic transmission) is used to engage the driveshaft connected to the rear differential. The new AWD system uses an electric motor to drive a single hydraulic pump, which operates the clutch. The electric motor is controlled by the Intelligent Control system, which means that the system can actively apportion power based on specific road conditions.
For example, when starting on snow the system sends power to the rear wheels right from the start which minimizes the potential for front wheelspin. In cooperation with the new Hill Start Assist feature, AWD with Intelligent Control can also detect when the RDX is climbing a hill- and can send a greater amount of power to the rear wheels.
Torque splits of AWD with Intelligent Control
During normal acceleration from a stop, AWD with Intelligent Control will send 75-percent of engine power to the front wheels with 25-percent of power sent to the rear wheels. When mild acceleration is needed (such as increasing road speed), 90-percent of power is sent to the front wheels with 10-percent power going to the rear wheels. During steady-state cruising, 100-percent of the engine power is sent to the front wheels.