ENGINE
The 2.4-liter SOHC four-cylinder engine (4G69) found in
the 2005 Outlander utilizes advanced Mitsubishi Innovative Valve timing and
lift Electronic Control (MIVEC) system technology to improve power output over
a wide rpm range without sacrificing emissions or fuel economy in the process.
The MIVEC system features
separate cam profiles for high and low engine speed modes, which translates to
higher maximum power and increased usable torque in the widest variety of
driving conditions. Under low-rev conditions, MIVEC selects the smaller cam
profile, which provides stable combustion and lower emissions. But when the
throttle is opened wide and engine speed increased, MIVEC allows the valves a
longer duration and longer stroke, thus providing maximum and efficient power
and torque over a broader range of engine speeds.
Variable
Lift Technology
The
enhanced power output of the MIVEC system is achieved by its ability to vary
the lift and duration of the intake valves. In the MIVEC system, there are
three distinct cam profiles that create two engine modes: a low-speed mode,
consisting of low- and mid-lift cam profiles; and a high-speed mode. The low-
and mid-lift cams and rocker arms – which drive separate intake valves – are
positioned on either side of a centrally located high-lift cam. The high-lift
cam is directly connected to a T-shaped lever, which controls valve lift and
duration of both intake valves in the high engine-speed mode.
At lower engine
speeds, the T-shaped levers connected to the high-lift cams reciprocate freely
without contacting intake-valve rocker arms, thus allowing the low- and
mid-lift cam lobes to control corresponding intake-valve lift and timing. The
intake rocker arms contain internal pistons that are retained by springs in a
lowered position at less than 3500 rpm, to avoid contacting the high-lift
T-shaped levers. The benefit of the dual-profile low-speed mode is to induce
swirl within the cylinder, which help create stable combustion and improve
emissions.
The high-speed mode
opens the valves longer due to its higher lift. At high engine speeds, the
pistons within the rocker arms elevate when MIVEC sends increased oil pressure
through an oil control valve. The high-lift cams’ T-shaped levers are then able
to directly contact the elevated rocker-arm pistons, overriding the low-speed
cam lobes and fully controlling intake-valve lift and duration.
The 4G69 engine
switches to a more aggressive cam profile at approximately 3500 rpm, when the
powertrain control module opens the valves longer to increase the amount of
intake airflow, resulting in higher engine output. More precisely, MIVEC
switches to the higher cam profile at 3600 rpm as engine speed increases, and
drops back to the lower cam profile at 3400 rpm as engine speed decreases; the
output torque of the low- and high-speed modes overlap at those speeds. This
also means that the cam switch operation is virtually transparent to the
driver, who is simply rewarded with more power.
Engine Summary
Under low-rev conditions the low- and mid-lift cam lobes
drive the intake valves, providing slightly better fuel economy and lower
emissions. But when the throttle is wide open and engine speed increased,
MIVEC gives the valves a longer duration and higher lift, thus providing
maximum and efficient power and torque over a very broad range of engine
speeds. Despite its technological complexity, the basic workings of the MIVEC
engine system can be expressed quite simply: MIVEC alters the cam profiles,
tailoring engine performance to suit your driving needs.
4G69 Engine
Modifications
Aside from its highly efficient valvetrain, the 4G69 with
MIVEC is a thoroughly re-engineered powerplant benefiting from mechanical
improvements that improve power production and durability while reducing the
mass of critical moving parts. All of the following feature comparisons are
to the non-MIVEC 2.4-liter (4G64) engine that powers Eclipse.
·
Intake. Several modifications were made to improve both
efficiency and performance. Starting with the incoming air, the aluminum intake
manifold’s interior surface was smoothed to increase intake efficiency. The
intake runners are also longer, and they feature a bell-mouth shape to reduce
air intake resistance.
·
Exhaust. More air coming in means more air needs to get out,
so the exhaust manifold was switched from single to dual ports, which reduces
interference and improves the flow of gases out of the combustion chamber.
·
Rocker cover. For better noise reduction and to reduce weight, the
rocker cover is made of aluminum instead of steel.
·
Combustion. More efficient combustion has been achieved by
increasing the compression ratio to 9.5:1 (from 9.0:1).
·
Valves. To improve high-speed efficiency, the valve sizes
were increased – intake valves are larger by 1 millimeter in diameter (to 34
mm), and exhaust valves were increased by 1.5 mm in diameter (to 30.55
mm).
·
Pistons. With the compression height reduced, the piston
height was reduced to match. Even though the pistons have a slightly larger
diameter (87 mm versus 86.5 mm), they are significantly lighter in weight (278
grams per unit compared to 354 grams). For moving parts, lower mass also means
better efficiency.
·
Connecting rods. The mass of each connecting rod was reduced from 623
g to 530 g.
·
Crankshaft. Once again engineers found a way to reduce the mass
of a moving part. The crankshaft’s weight was reduced from 15.8 kg to 14.9 kg.
In addition, the crankshaft pulley’s weight was reduced at the same time its
size was increased. By using aluminum in the hub in place of steel, the
pulley’s weight was reduced from 2.9 kg to 1.8 kg, a savings of 1.1 kg.
·
Timing belt. Shortening the width of the timing belt reduced
weight and friction. To further reduce weight, the auto tensioner is now made
of aluminum instead of cast iron.
·
Serpentine drive belt. The 4G69 MIVEC engine uses a single serpentine belt
to operate the engine’s accessory drives for the power steering, alternator,
and air conditioning unit. In addition to saving space compared to the
dual-belt drive system used on the previous engine, the low-maintenance
serpentine belt features an auto tensioner.
CYLINDER block
The height of the cylinder block was reduced to decrease
weight, and the water jacket’s length was shortened to help warm the engine
faster for better fuel consumption. Also, air bleed holes were added to the
main webs to reduce piston movement resistance, which is created by pressure
pulsation when the piston is in motion. Also, the new cylinder block reroutes
the oil returning from the head to reduce interference between the oil and the
rotating crankshaft.
Engine Block - Illustration shows that 4G69 engine block is dramatically revised over the basic 4G64 engine block.
Another feature that contributes
to the 2.4-liter engine's responsiveness is a high-velocity runner intake
manifold with a cold-air induction system. Drawing air from above the radiator
rather than from inside the hot engine compartment, the cold-air induction system
allows a cooler, denser charge of air/fuel mixture to be fed to the cylinders.
This combination produces a more complete and powerful combustion. The intake
manifold runners are tuned for mid-range punch and contoured to increase
airflow at both low and high engine speeds.
Also, counter-rotating balance shafts quell the low-speed
rumble and high-rpm tremble inherent in large, powerful four-cylinder engines.
An induction-hardened steel crankshaft insures stability for the reciprocating
assembly. Thanks to a liquid-filled engine mount that isolates the engine from
the chassis, the Outlander provides a refined driving experience rarely
achieved in a four-cylinder SUV.
Engine Features
TRANSMISSION
Four-Speed
Automatic with Sportronic™ Sequential Shifter
All Outlander’s are equipped with a 4-speed automatic
transmission with Sportronic™ mode that allows drivers to manually actuate gear
changes. This transmission comes equipped on both the 2WD and AWD versions of
the Outlander. In standard Drive mode (“D”) an INVECS-II program controls the
shifting action to match the road conditions and the driver’s accelerator
movements. The INVECS-II computer calculates each driver’s reaction and
tailors the gearbox’s reactions accordingly. When the lever is pushed to the
right, into the Sports Mode gate, clutchless shifts can be manually actuated
with just a push or tug of the shift lever.
Five-Speed Manual (Outlander LS)
For 2005, the Mitsubishi Outlander offers a 5-speed
manual transmission for the LS trim level. Like the transmission in the sporty
Eclipse Coupe, double-cone synchronizers on first gear and triple-cone
synchronizers on second gear help to ensure smooth gear transfers and ease of
use. The optimally spaced gears help maximize the MIVEC motor’s powerband.
Reverse gear also is fitted with dual-cone synchronizers for easy gear
engagement to eliminate gear grinding and help improve reliability. The
transmission shifter features a fulcrum-action lever that reduces the range of
motion needed to select a gear, providing a more positive feel.
Transfer Case
On all-wheel drive
Outlanders, the center differential operates to regulate an equal torque split
between front and rear wheels. Under normal driving conditions torque is split
evenly between the front and rear wheels. When the system detects slip in any
of the wheels, as may occur at high speeds while in the rain or on pavement, or
when driving over dirt, sand or snow-covered surfaces, the VCU (Viscous Coupling
Unit) automatically regulates torque split in proportion to the rotational
speed differential between the front and rear wheels. This system manages the
torque split between the wheels in such a way to deliver optimum traction in
all conditions. The Outlander’s transfer case design was tested in World Rally
Championship competition with the Lancer Evolution series of vehicles.
Suspension
The Mitsubishi Outlander’s dual nature as an urban
cruising and gravel road SUV required engineers to design a suspension to cope
effectively with both environments. Though similar to the Lancer’s suspension
design, the Outlander’s suspension design is revised, upgraded and reinforced
in numerous ways to achieve the optimum balance between ride quality, car-like handling,
and ruggedness in both urban and light-off road environments.
Front Suspension
The Outlander’s front wheels rely on a proven, rugged
MacPherson strut arrangement to provide superior all-terrain performance with
outstanding handling stability. The struts dampen road harshness with the help
of a gas charged insert. By optimizing key suspension characteristics such as
toe, camber and other alignment parameters, engineers are able to produce a
flexible, responsive vehicle that is fun to drive. The Outlander chassis boasts
a significantly reinforced steel front suspension cross member that helps
increase suspension mounting point stiffness by 30 percent. Rugged, enlarged,
lower control arms pivot from these reinforced mounting positions. The front suspension
sway bar, which attaches to the suspension using ball joints and rubber
stabilizer links, has been stiffened and its mounting points optimized
to suppress body roll. Engineers paid careful attention to the selection of
tuned coil springs to help strike a balance between stable, sporty handling and
a compliant ride.
Rear Suspension
The Mitsubishi
Outlander’s rear suspension utilizes a sophisticated multi-link, trailing-arm
design. This suspension design includes extended-length trailing arms, an
elongated lower control arm, a stiff upper link and additional links that
attach to the trailing arm to the unibody for improved lateral stability.
Suspension component mounting points have been repositioned and alignment
changes made to give this Outlander its unique handling characteristics and
superior all-around performance. The Outlander’s rear trailing arms are
positioned wide to match the increased width of the front track. A reinforced,
rear suspension cross member spans the mounting points, and helps inhibit rear
deck flex. On AWD models, the rear differential is mounted to this cross
member with vibration canceling mounts for a smoother ride.
Most of the rear suspension’s mounting points rely on
stable, friction-free pillow-ball style bushings for movement. This compact,
long travel rear suspension system helps Outlander to offer superior
all-weather handling and comfort, while maximizing the useful interior space.
Steering
Outlanders come equipped with either a leather or
urethane-covered four-spoke, tilt steering wheel to help accommodate various
shapes and sizes of driver. The steering column shaft is designed as a
collapsible mechanism that helps absorb impact energy in the event of a
collision. All Outlanders are equipped with power rack and pinion steering
system.
Outlander P/S Gear Specifications
|
Type
|
Rack and
Pinion
|
|
Pinion
Gear Teeth
|
9
|
|
Stroke
Ratio
|
51.45
|
|
Pressure
Area (cm²)
|
1.40 in.2
/ 8.88 mm
|
|
Rated
Torque
|
2.95 lbs.
ft.
|
|
Rack
stroke
|
5.55 in.
/ 141 mm
|
This power steering system is designed and tuned to be
responsive to slight inputs on the steering wheel, making the vehicle a snap to
maneuver in parking situations. In addition to the light effort gearing of the
steering rack, the output and flow characteristics of the pump were also
improved to meet more stringent driving demands with higher and more consistent
fluid pressure. This easier, more car-like handling nature was a virtue
designers sought to include in the Outlander.
Brakes, Wheels & Tires
For 2005, all Outlanders come equipped with hydraulic,
ventilated front disc brakes and solid rear disc brakes that are aided by a
tandem brake booster system, which helps reduce pedal effort. In addition,
larger diameter brake caliper pistons help increase the effectiveness of the
brakes without an increase in pedal effort. This system is designed to help
ensure ample, stable braking power for the Outlander in all conditions,
including deceleration from high speeds. The security of 4-channel ABS is
available on Outlander (optional on XLS AWD, standard on Limited AWD), and also
includes an EBD (Electronic Brake Force Distribution) system that increases
control and safety under heavy braking.
Outlander Brake Specifications
|
Front Brake Rotor Diameter
|
10.9 in. / 276 mm
|
|
Front Brake Rotor Width
|
1.02 in. / 26 mm
|
|
Rear Brake Rotor Diameter
|
10.3 in. drum / 262 mm
|
|
Rear Brake Rotor Width
|
.394 in / 10 mm
|
|
Total Swept Area Front Brake
|
211.3 sq. in.
|
|
Total Swept Area Rear Brake
|
140.2 sq. in.
|
|
Master Cylinder Diameter
|
25.4 mm
|
|
Vacuum Assist
|
Tandem
|
|
Fluid Pressure Control
|
Pressure Control Valve
|
Outlander
Wheels and Tires
Two distinct wheels are available on the 2005 Outlander.
The base LS arrives with a 16 in. x 6 jj. steel wheel with an
attractive wheel cover wrapped in a P225 / 60R16 all season, radial tire. For
2005, the XLS and Limited ride on an attractive 17-inch alloy, five-spoke
design. The Outlanders 17-inch wheels wear P215/55R17 all-season rubber.
Unibody and Safety
Building upon basic elements of the Lancer sedan platform,
the 2005 Mitsubishi Outlander relies upon a thoughtfully designed steel
skeleton to provide high levels of chassis rigidity and safety. The
Outlander’s all steel unibody is welded together using the most modern methods,
such as MASH seam welding and Mitsubishi’s RISE (Reinforced Impact Safety
Evolution) design. The resultant steel structure, with its carefully layered
pressed metal panels joined by controlled welds, creates a structure that
surrounds passengers in a highly impact absorbent front and rear structure.
The center of the cabin is a highly rigid compartment designed to offer
occupants maximum protection in the event of a collision.
Examples of Unibody Enhancement for Superior Rigidity and Handling
The Outlander’s rear hatch aperture is constructed using
a skeleton of pressed-sheetmetal pieces strategically joined to create a
continuously welded structure. By increasing the thickness of the metal and
the amount of overlap at the welded unions, the entire rear hatch opening
assembly helps yield a superior level of torsional rigidity for the rear
section of the Outlander body. This reduction in unibody flex contributes to
the Outlander’s stable handling characteristics, making the suspension, and not
the unibody, adapt to road conditions.
Thoughtful Design Refines a Platform
The Outlander’s rear suspension spring mount is attached
in a low, compact position. The lower profile position of the rear strut
mount, and the elimination of a traditional, taller strut-tower structure,
helps to increase vertical and horizontal rigidity for improve suspension
action. A reinforced metal plate also was welded to the top of the rear strut
mount to help further strengthen this suspension mounting point.
The enlarged profile of the upper frame rail combined with
a closed section front deck increases the front-end rigidity and helps control
front to rear and left to right flexural forces. In addition, the careful
positioning of a bulkhead inside of the upper frame helps create highly
responsive steering and a quieter, more refined ride.
Structurally-critical, stress-bearing components such as
the center-pillar reinforcements, front sub-frame rails, and front-end cross
members are constructed using MASH-seam welding techniques which fuse multiple
sheets of thinner metal together to produce a more rigid structure.
Noise Vibration Harshness
In keeping with the concept of building a more refined
entry-level SUV, the Outlander’s designers incorporated several measures to
limit the amount of vibration and noise that enters the cabin. Outlander’s
pillars have been filled with vibration canceling foam, and sound insulating
pads have been carefully placed throughout the floorpan. The urethane foam
used in the pillars and filler pads located in other structures is especially
effective in canceling resonant road vibrations. The surfaces under the
floorpan make extensive use of asphalt sheets to help further reduce detectable
road noise in the cabin.
Warranty and
Manufacturing
As part of Mitsubishi Motors “Best-Backed Car”
program, all models are backed by a comprehensive new vehicle limited warranty
that covers the vehicle from bumper-to-bumper for five-years/60,000 miles. In
addition, the powertrain is covered by a 10-year/100,000 mile limited warranty,
while body panels have a seven-year/100,000 mile anti-corrosion/perforation
limited warranty. The “Best-Backed Car” program also includes 24-hour emergency
roadside assistance with free towing to the nearest authorized Mitsubishi
retailer for warranty-related repairs for five years/unlimited miles.