2006 Ford Explorer Powertrain

     Special Features

    2006 Ford Explorer Powertrain


    The 2006 Ford Explorer’s advanced engine
    technologies improve both the drive experience and the environment.

    The 2006 Explorer with the standard V-6 engine produces 74
    percent less smog-forming emissions than the previous model. In
    fact, V-6-powered Explorers are expected to be certified to the same
    federal tailpipe emissions standards as the Ford Escape Hybrid, the
    world’s cleanest SUV.

    Additionally, fuel economy for the
    all-new 4.6-liter three-valve V-8 engine paired with the new
    six-speed transmission is expected to increase by up to 10 percent,
    while delivering 53 more horsepower.

    “Performance and fuel
    economy can go hand-in-hand if you invest in the right
    technologies,” says Dave Szczupak, vice president, Powertrain
    Operations. “That’s why Ford is investing in six-speed automatic
    transmissions, electronic throttles, variable cam timing and other
    advanced powertrain technologies.”

    Ford has a leadership
    position in powertrain technologies such as six-speed automatic
    transmissions to simultaneously boost performance — without
    necessarily going to larger engines — and fuel economy with
    the wider ratio spreads allowed by the extra gear. This investment
    in technology is particularly appropriate in the SUV market, where
    Ford is increasing capability without resorting to
    larger-displacement engines that consume more fuel.

    new V-8 and six-speed automatic drivetrain is a tremendous advantage
    for the 2006 Explorer,” says Raj Nair, SUV and Body-on-Frame
    Vehicles executive director. “Not only does it offer more power,
    more refinement and better fuel economy, but it also offers
    increased utility. The additional power output helps Explorer
    deliver improved payload — up to 1,520 pounds — and a
    7,300-pound maximum towing capacity when properly equipped.”

    Explorer’s standard powertrain is a refined version of the
    SOHC 4.0-liter V-6, paired with a five-speed automatic. Both
    powertrains boast modifications to improve noise, vibration, and

    Three-valve heads,
    variable cam timing, muscle car power

    The 2006 Ford Explorer features a new,
    4.6-liter, 3-valve V-8 with variable cam timing, delivering 292 hp
    and 300 ft.-lbs. of torque.

    The most
    significant powertrain improvement, from the driver’s perspective,
    is the new 4.6-liter V-8, with three-valves per cylinder, and single
    overhead cams with variable cam timing. These features are common
    with the highly lauded 2005 Ford Mustang GT, as well as the
    5.4-liter V-8 in the F-Series pickups and Expedition. With the
    introduction of the Explorer, Ford Motor Company is approaching one
    million three-valve V-8s produced. This multi-application approach
    to Ford’s “modular” V-8s delivers benefits in manufacturing
    efficiencies, proven customer reliability, and performance.

    In the Explorer, the 4.6-liter V-8 delivers 292
    horsepower. The slight decrease in output from Mustang’s 300
    horsepower can be attributed to a more restrictive exhaust necessary
    to accommodate Explorer’s available four-wheel-drive system.

    The new head enables a higher compression ratio on regular grade 87
    Octane gasoline. Two of the three valves assigned to each cylinder
    are intake valves because more airflow into the engine means more
    power output. A new, tuned-length exhaust manifold offers optimized
    exhaust flow to help scavenge burned gases from the cylinders.

    The three-valve heads feature center-mounted sparkplugs
    that offer three benefits:

    • Placing the sparkplug in the
      center of the cylinder provides symmetrical flame for more complete
      fuel combustion. This extracts more power from the engine while
      decreasing the amount of unconsumed fuel in the exhaust system,
      resulting in low emissions
    • A longer and narrower spark
      plug design enabled powertrain engineers to use larger-diameter
      valves, for increased economy and performance
    • The compact
      coil-on-plug ignition system enables the powertrain control module
      (PCM) more precise spark control, again for improved efficiency

    The three-valve heads are smaller and lighter than
    equivalent four-valve heads. Their large dual intake ports provide
    a direct path to the twin intake valves for better airflow at peak
    engine speeds. At lower speeds and loads, a charge motion control
    valve (CMCV) closes, increasing air velocity and in-cylinder motion
    for optimum fuel economy. Likewise, lightweight intake and exhaust
    valves reduce inertia for high-speed performance capability, while
    enabling lower friction for fuel economy. The cylinder heads are
    capped with lightweight magnesium cam covers that help suppress
    valvetrain noise.

    The ABCs of

    Variable camshaft timing (VCT) plays an
    important part in generating more power as well as improving
    efficiency and reducing emissions.

    The VCT system allows
    up to 50 degrees of cam variation in relation to the crankshaft
    angle. Ford’s “dual-equal” variable cam timing design shifts the
    timing of both the intake and exhaust valves together, with a single
    camshaft per cylinder head. This provides all the benefits of
    variable valve timing — but creates far less complexity and
    adds less weight than VCT systems that actuate the intake valves

    The single-overhead-cam heads feature “dual
    equal” variable cam timing that rotates the camshafts up to 50
    degrees in relation to the crankshaft.

    The cam in each cylinder head operates both sets
    of valves using low-profile roller-finger followers, helping reduce
    friction. The powertrain control module (PCM) directs solenoids to
    alter the oil flow in the hydraulic cam timing mechanism, which
    rotates the camshafts in relation to their drive sprockets. The
    unit can shift between fully advanced and fully retarded in

    The result is enhanced efficiency under
    low-load conditions, such as at idle or highway cruising, and
    increased power for brisk acceleration for times of high

    Paired with the six-speed automatic, 4×4 V-8 models
    are expected to deliver up to a 10 percent increase in fuel economy,
    or two miles per gallon. Just as significant, it is anticipated to
    qualify for Tier II Bin 5 emissions certification, which is
    compliant with California’s Low Emissions Vehicle II (LEV II)

    six-speed automatic transmission

    The 4.6-liter V-8
    comes standard with a new six-speed 6R automatic transmission,
    introducing transmission technology normally found only in luxury
    vehicles to the mid-price mid-size SUV segment.

    For the
    best possible shift quality, each 6R transmission is bench tested at
    Ford’s Livonia (Mich.) Transmission Plant. There, the transmission
    build quality is verified, detecting even minute variabilities in
    the manufacturing process. These variances would normally lead to
    changes in shift feel. However, the 6R’s electronic controller is
    programmed with its own unique software to account for these
    variances, producing smooth, precisely controlled shifts that
    improve durability and customer satisfaction.

    The class-leading, six-speed 6R electronically
    controlled transmission features the first console-mounted shifter
    in an Explorer.

    The electronically controlled
    transmission offers the smooth shift quality of a luxury car, but is
    fully tested for heavy-duty use. In fact, it contributes to the
    7,300-pound maximum towing capacity of the V-8 drivetrain. For
    example, the torque converter assembly features three friction
    plates with improved durability, and increased cooling flow for
    heavy-duty, high-load use.

    New for 2006, the transmission
    selector is mounted on the center console (rather than the steering
    column.) As a result, the transmission can be shifted manually with
    crisp response, thanks to full electronic solenoid control of the
    clutch elements. Lastly, focalized transmission mounts mean an even
    greater reduction in NVH levels.

    The 6R has a 6.04:1 gear-ratio span. The company’s 5R55W5 automatic
    has a span in the range of 4.5:1. The wide ratio span of the 6R
    enables the engine to spend more time in the optimum powerband
    — either at peak power for acceleration, or at peak efficiency
    for more fuel economy.

    emissions on standard V-6 engine

    Explorer’s standard
    4.0-liter SOHC V-6 engine received significant improvements for the
    2006 model year as well. New engine calibrations and an improved
    emission controls cut smog-forming emissions by 74 percent. Idle
    quality was improved by 50 percent, thanks to a new camshaft and
    spark plugs.

    The 4.0-liter SOHC V-6 produces the same 210 hp
    of its predecessor, but now produces 74 percent less smog-forming

    Additionally, the 2006 Explorer V-6 is expected to be certified to
    the same federal tailpipe emissions standards as Ford’s Escape
    Hybrid, the world’s cleanest SUV.

    The 4.0-liter V-6 is
    rated at 210 horsepower at 5,100 revolutions per minute and 254
    foot-pounds at 3,700 revolutions per minute.

    The torque
    curve is designed to be relatively flat across the entire engine
    range and to provide strong performance at nearly any engine speed.
    An equal-length composite plastic intake system improves sound

    The V-6 engine comes with a five-speed automatic
    transmission. The wide-ratio five-speed 5R55W provides good
    acceleration and fuel economy. In addition, the 5R55W has a single
    aluminum transmission casting that greatly reduces NVH and
    powertrain bending at higher speeds. To reduce noise, it utilizes a
    quieter oil pump and planetary gear designs.

    Cooling system designed to pass rigors of Ford
    truck towing tests

    The 2006 Explorer also features
    an improved cooling system, delivering increased capability,
    decreased NVH, and improved fuel economy.

    The clutch that
    operates the cooling system fan is now under the command of the
    powertrain control module. This electronic control allows the fan
    to be operated at just the right time to keep the engine within the
    proper range of operating temperature yet not run so long as to draw
    off engine power and draw down fuel economy. Controlling when the
    fan operates, how long it operates and how fast it operates also
    makes it less intrusive in terms of NVH.

    The cooling system
    is a key component in the Explorer’s impressive payload and towing
    capability. One of the most tortuous tests Explorer is subject to
    is the Davis Dam towing test in Arizona. The truck is loaded down
    to its maximum gross vehicle weight, and then climbs up the Davis
    Dam grade as the ambient temperature peaks over 100 degrees. This
    is just one of the battery of towing tests Explorer must pass to
    certify that its engine and transmission cooling systems are up to
    the task, not to mention its engine calibration and system hardware.

    New driveshafts improve

    As part of its campaign to elevate refinement of
    the 2006 Explorer, Explorer also features new driveshafts.

    On V-6 models, the traditional aluminum-tube driveshaft is
    engineered for improved balance and decreased run-out.

    accommodate the longer 6R transmission, V-8 Explorers have new,
    improved “slip-in-tube” driveshafts. These feature a pair of
    splined tubes that plunge into one another, eliminating the need for
    the steel slip and forged stud yokes used in conventional
    slip-between-center driveshafts.

    2006 Explorer 4×4 models feature improved
    slip-in-tube driveshafts, differential mounts and transfer-case
    mounts for improved NVH isolation.

    The slip-in-tube
    driveshaft is more resistant to bending than conventional
    driveshafts and thus is inherently less prone to NVH. In addition,
    the increased overlap between the tubes enables increased driveshaft
    extension, as well as increased durability.

    A computer
    numerically controlled (CNC) cold rolling spline process is used to
    make the slip-in-tube driveshaft. That means that no material
    — inside or outside — is machined away. The primary
    benefit of this process is that it allows the tubes to slide in and
    out of each other easily, even under heavy torque, which eliminates
    unpredictable NVH behavior and provides a smooth, quiet ride.

    Finally, the rear differential mounts of all 2006
    Explorers have been reconfigured for improved isolation, greater
    durability and reduced NVH. The differential is suspended by four
    mounts: Two, close-set, vertical mounts are connected to the front
    of the differential casing, while two vertical mounts have a wider
    stance at the rear of the casing. Like the legs of a table, these
    wide set mounts better stabilize the differential, for improved
    isolation and durability.

    Control Trac® delivers automatic torque
    split, low-range

    Explorer continues to offer the
    advanced Control Trac® four-wheel-drive system. It includes
    electronic logic and a two-speed transfer case with a locking center

    Control Trac® is an advanced
    four-wheel-drive system that allows a driver to select between three
    driving modes:

    • The 4×4 AUTO (or A4WD) mode provides full
      power to the rear axle until the rear wheels begin to slip. Then
      power is automatically proportioned to the front axle as required
      for increased traction. This mode is appropriate for any driving
    • The 4×4 HIGH (4H) mode effectively locks the
      center differential, providing a constant 50/50 torque split between
      the front and rear axles. It only is intended for severe winter or
      off-road conditions, such as deep snow and ice and shallow sand.
    • The 4×4 LOW (4L) mode locks the transfer case and engages
      a torque-multiplying gear set in the transfer case. It only is
      intended for off-road applications that require extra power
      including deep sand, steep grades and towing a boat trailer out of

    These powertrain changes help Explorer retain its
    leadership, offering genuine SUV capability to tow or go off-road,
    without compromising the fuel-economy, refinement, or performance
    that have made the Explorer the benchmark of its class.