The Mitsubishi Diamante stands as a testament to sophisticated automotive engineering, offering a blend of powerful performance and near-luxury refinement. At its heart lies a robust engine, meticulously designed to deliver both exhilarating power and smooth operation. Let’s delve into the intricate details of what makes the Mitsubishi Diamante a standout in its class.
Engine: The Powerhouse Under the Hood
The Diamante boasts a potent 3.5-liter, SOHC, 24-valve V6 engine, engineered to produce an impressive 205 horsepower (and even 210 hp in the VR-X variant) at 5000 rpm. Complementing this power is a substantial 231 pound-feet of torque at 4000 rpm, ensuring responsive performance across the rev range. The VR-X model elevates the performance further through a less restrictive exhaust system, unlocking additional power and a sportier engine note. This robust V6 enables the Mitsubishi Diamante to accelerate from 0 to 60 mph in a swift 8.1 seconds, positioning it as a capable performer in its segment.
Alt text: Detailed view of the Mitsubishi Diamante engine bay, showcasing the 3.5-liter V6 engine.
Several advanced engineering principles are integrated into this engine’s design. The 60-degree cylinder arrangement inherently ensures smooth operation, while the durable cast-iron block provides a solid foundation. Weight-saving aluminum heads contribute to overall vehicle agility, and quiet, belt-driven camshafts along with friction-reducing roller-type rocker arms enhance efficiency and longevity. Furthermore, hydraulic valve lash adjusters eliminate the need for routine valve adjustments, reducing maintenance and ensuring consistent performance over time.
The engine’s combustion chamber features a compact pent-roof design, optimized for high combustion efficiency and minimized exhaust emissions. The central placement of the spark plug within the chamber promotes faster and more stable combustion. The four-valve cylinder head design enhances engine breathing, allowing for improved airflow and consequently, greater power output.
Mitsubishi engineers employed advanced computer-aided design techniques to ensure engine rigidity and reliability. This meticulous approach included determining the optimal thickness for the cast-iron cylinder block and strategically positioning stiffening ribs to maximize structural integrity. A forged steel crankshaft is incorporated within the reciprocating assembly, chosen for its superior durability and ability to withstand high stresses.
The crankshaft rotates within heavy-duty, four-bolt main-bearing caps, interconnected by a full-web girdle. This robust arrangement is engineered to enhance engine smoothness, improve overall engine rigidity, and effectively dampen vibrations originating from crankshaft flexing, resulting in a refined and quieter driving experience.
Transmission: Seamless and Adaptive Power Delivery
The Mitsubishi Diamante ES model is equipped with a sophisticated four-speed, electronically controlled automatic transmission. This transmission features Mitsubishi’s Adaptive Shift Control, an intelligent system that “learns” the driver’s habits and driving style. By adapting to individual driving patterns, the transmission tailors its shift points to optimize responsiveness and fuel efficiency, providing a personalized driving experience.
In the LS and VR-X trim levels, the Mitsubishi Diamante steps up to the Sportronic™ transmission. This advanced system offers the versatility of both a traditional fully automatic mode and a driver-selectable clutchless manual shift mode for those seeking a more engaging driving experience. The Sportronic™ INVEC-II system further refines the driving experience by continuously learning driver throttle inputs and adapting its shift patterns accordingly. A user-friendly four-position shift lever, complete with a Sports-mode gate, allows drivers to effortlessly engage manual shifts with a simple push or pull of the lever, providing sporty, tactile gear changes.
Alt text: Close-up of the Mitsubishi Diamante Sportronic gear shift, highlighting the manual shift mode option.
In fully automatic mode, the Sportronic™ transmission exhibits intelligent behavior. It will proactively downshift for engine braking when it detects frequent braking during downhill driving. Conversely, when climbing hills, the transmission will hold a lower gear to ensure ample power is available and to prevent the annoyance of constant gear hunting between upshifts and downshifts, maintaining smooth and consistent performance in varying terrains.
Suspension: Engineered for Confident Handling and Ride Comfort
The Mitsubishi Diamante’s confident and composed handling characteristics are largely attributed to its well-engineered fully independent suspension system. The front suspension utilizes a MacPherson strut design, known for its effective combination of handling precision and ride comfort. At the rear, a multi-link setup is employed, offering superior control over wheel movement and contributing to both handling agility and ride sophistication.
For enhanced durability and handling precision, the front struts are designed with a large, rigid cross-section. This robust design resists bending and twisting forces, leading to more accurate control of wheel geometry and consistent handling performance, even under demanding driving conditions. The lower arm of the suspension is attached to a precision-cast aluminum crossmember. Aluminum construction reduces weight compared to conventional steel, improving agility and responsiveness, while also providing more accurate wheel alignment. Rubber bushings isolate the crossmember from the body, minimizing the transmission of vibrations and road noise into the cabin. Furthermore, the lower arm is mounted to the crossmember using liquid-filled bushings. These advanced bushings effectively absorb vibration, road harshness, and noise, further enhancing ride comfort and refinement.
The sophisticated rear multi-link suspension design comprises a pair of high-mounted upper A-arms (wishbones), two lower trailing links, and four lower transverse, unequal-length control arms. The upper wishbones are connected to the lower links via long “twisted” arms, which serve as mounting points for each wheel hub. The carefully engineered configuration and geometry of the upper arms effectively resist bending forces from camber changes, while also ensuring excellent straight-line stability, contributing to confident and predictable handling.
The suspension geometry is optimized to provide excellent stability during acceleration and to minimize body dive during braking and squat during acceleration. The Mitsubishi Diamante’s chassis tuning incorporates front and rear stabilizer bars. These bars effectively control body roll during cornering, enhancing stability and driver confidence in turns. The rear stabilizer bar and trailing links are mounted using pillow-ball bushings. Pillow-ball bushings offer smooth, progressive roll control and effectively reduce rear impact harshness, further refining ride quality.
Steering: Responsive and Connected to the Road
All Mitsubishi Diamante models are equipped with speed-sensitive, power-assisted rack-and-pinion steering. Requiring only 3.1 turns lock-to-lock, the steering system offers a quick response and reassuring feel, providing the driver with constant feedback about the road surface and the car’s directional dynamics. The variable assist nature of the system is subtly but effectively implemented. It adjusts seamlessly and proportionally to engine speed. At lower speeds, such as during parking maneuvers, the steering provides greater power assist, making low-speed maneuvering easier. As speed increases, the steering’s reduced power assist enhances road feel, providing the driver with a more connected and stable sensation at higher speeds, promoting directional stability.
Brakes, Wheels & Tires: Confident Stopping Power and Grip
To ensure confident stopping power, four-wheel disc brakes are standard equipment on the Mitsubishi Diamante, reflecting its commitment to performance and safety. The brake system includes an antilock braking system (ABS). ABS enhances steering control during emergency braking situations by preventing wheel lock-up, allowing the driver to maintain directional control while braking hard. Electronic Brakeforce Distribution (EBD) further enhances braking performance. EBD intelligently monitors traction conditions and dynamically distributes hydraulic braking force between the front and rear brakes, optimizing braking effectiveness based on weight distribution and road conditions.
The Mitsubishi Diamante comes standard with V-rated P215/60R16 all-season performance tires. These tires are mounted on stylish six-spoke alloy wheels, combining aesthetic appeal with performance capabilities.
Alt text: Close-up of a Mitsubishi Diamante six-spoke alloy wheel and all-season performance tire.
Safety: Prioritizing Occupant Protection
The Mitsubishi Diamante incorporates a comprehensive suite of safety technologies, designed to enhance occupant safety in the event of a collision. Mitsubishi Motors engineers employ the acronym RISE—Refined Impact Safety Evolution—to encapsulate their commitment to elevating safety standards.
A multitude of structural elements work in concert to create a robust safety cage around the vehicle’s occupants. These elements include high-rigidity side members, roof reinforcement, large-section side sills, reinforced door frames, and side-guard beams. This robust skeletal structure enhances safety performance in offset crashes and side-impact collisions. Additionally, front and rear crumple zones are strategically designed to absorb impact energy, effectively dissipating crash forces away from the passenger compartment, further protecting occupants.
Even the crossmember supporting the steering column plays a role in passenger protection. This crossmember acts as an integral part of the front bulkhead, enhancing structural resistance in a front impact. It also contributes to overall rigidity in the event of a side impact, reinforcing the vehicle’s safety structure.
In addition to the standard antilock braking system, a traction control system (TCL) is available as part of the Cold Zone Package on the LS model. In its fundamental operation, TCL prevents the drive wheels from spinning on slippery surfaces. When the system detects excessive wheel slip, the TCL microprocessor collaborates with the engine management system to momentarily reduce engine power. This intervention continues until optimal driving force is safely restored, maximizing traction and control in challenging conditions.
In the event of a collision, the Mitsubishi Diamante is equipped with a driver’s and front passenger’s airbag Supplemental Restraint System (SRS). Furthermore, driver and passenger seatbelt pretensioners are designed to automatically tighten the seatbelts upon impact, securely restraining occupants against their seats. The pretensioners work in conjunction with seatbelt force limiters. Force limiters gradually reduce pressure exerted by the shoulder belt during an impact once a predetermined load is reached. This controlled release of tension helps to decelerate the passenger in a more controlled manner, reducing the peak impact load experienced in a frontal collision.
Warranty: Peace of Mind Ownership
The Mitsubishi Diamante is backed by a comprehensive New Vehicle Limited warranty from Mitsubishi Motors, providing owners with peace of mind. This warranty covers the vehicle from bumper-to-bumper for three years or 36,000 miles, demonstrating Mitsubishi’s confidence in the Diamante’s quality and durability. Furthermore, the powertrain and restraint systems are covered by a five-year or 60,000-mile limited warranty, providing extended protection for critical components. Body panels are also covered by a seven-year or 100,000-mile anti-corrosion/perforation limited warranty, safeguarding against rust and corrosion.
The warranty service also includes 24-hour emergency roadside assistance for three years or 36,000 miles. This service provides free towing to the nearest authorized Mitsubishi retailer for warranty-related repairs, ensuring prompt and convenient assistance in case of unforeseen issues. Mitsubishi also extends assistance with hotel and rental car arrangements and contacting family members, demonstrating a commitment to customer care beyond the typical warranty coverage.
1. Motor Trend.com Buyer’s Guide, September 20, 2001
