The Chevrolet SSR builds on Chevrolet’s semi-forgotten tradition of curvy trucks, so it is not just an imitation of the PT Cruiser or Plymouth Prowler.
The Chevy SSR combines the open air of a sports roadster with a pickup bed. A retractable hardtop - which remains in the production version - makes it a practical street machine. The two-piece power retractable hardtop stows vertically between the seat and the rear storage bed.
Like the Trailblazer, which it is based on, the SSR features a hydroformed steel frame with eight crossmembers for stiffness and handling. The engine crossmember was modified to fit the SSR’s V-8. Due to its superior stiffness, hydroforming is becoming the new standard, having been adopted in the heavy-duty Dodge Rams and Dodge Durangos as well.
The production version has somewhat larger headlights and smaller turn signals than the concept, with small changes to the fenders and grille.
A 5’3" x 4’7" covered, lockable pickup box is included with the Chevy SSR concept for hauling. A button on the key fob of the SSR concept can operate the tailgate remotely; a latch on the inside of the tailgate can operate the gate manually.
The SSR conceals controls for temperature, sound, navigation, weather information, Internet/e-mail access, and OnStar behind a dashboard-mounted panel door.
The interior plays off a twin cockpit theme, presenting a clean, simple, comfortable environment. The storage area between the seats can be stowed away to provide seating for a third person or a child seat, or it can act as an armrest with cupholders that slide out from inside.
The production model, unlike the concept, has bucket seats, a center console, and, a conventional shifter. However, it retains the large (19" and 20") wheels and performance tires.
New aluminum version of the Vortec 5.3
GM used an aluminum Vortec 5.3 liter engine with its Hydramatic 4L60-E automatic transmission.
The all-aluminum version of the 5.3 had a variety of improvements. The engine block is 100 pounds lighter than the standard truck version of the 5.3 V8, and is cast of Vortec 5300 Improvements Chevy’s new roadster features the Vortec 5300 engine, refined to provide a quieter, yet more aggressive driving experience for the SSR customer. The all-aluminum 5.3-liter V8 will showcase a variety of performance, durability and noise improvements, resulting from innovative use of structural materials, calibration and components.
319-T7 aluminum alloy. Aluminum’s thermal characteristics provide improved heat rejection, resulting in cleaner emissions from faster catalytic converter "light off," faster heater core warmup for vehicle occupants, and cooler piston and oil temperatures for improved durability.
The all-aluminum Vortec 5300 V8 builds on the small-block tradition started by the 5.7-liter V8s featured in the Chevrolet Corvette. The engine block is produced by the gravity-poured precision sand casting process. This process allows cylinder liners to be cast in-place and yields exceptional cast quality. The engine is tested to identical levels of endurance as the cast-iron Vortec 5300 engine.
The engine features new quiet-profile pistons to ensure that the pistons track straight in their bores, minimizing clearances as the pistons rock under gas pressure. The pistons are polymer-coated to reduce cold scuffing and engine noise. Polymer-coated pistons, long a mainstay in luxury car engines, enable tighter bore clearances, provide enduring wear surfaces between pistons and cylinder walls, and further reduce piston motion.
The deep-skirt engine block design, with six-bolt main bearings, allows cross bolting of the bearing caps, limiting crank flex, stiffening the engine’s structure and reducing overall vibration.
The also saves weight with a new oil pan design. Due to the lower, shorter design of the SSR, the new "pan-axle" design allows the front differential to pass through the oil pan, resulting in weight savings, while optimizing the use of under-hood space. (Note: this paragraph was taken from a GM press release on the SSR, but GM may have used it by accident since there will reportedly be no all wheel drive SSR).
Exhaust catalyst and emissions control system calibration have been improved to allow the engine to meet federal emissions and California Ultra Low Emissions Vehicle (ULEV) standards without an Exhaust Gas Recirculation (EGR) system.
The aluminum engine, like its iron sibling, uses platinum-tipped spark plugs to extend plug life to 100,000 miles, while the coolant maintains its cooling and corrosion-inhibiting properties for 150,000 miles. Scheduled maintenance is limited to oil changes when indicated by the engine oil life monitoring system or at 10,000 mile intervals (whichever comes first). The cam is within the block.
The Hydra-Matic 4L60-E transmission, an electronically controlled, updated "turbo 350," is used in many GM cars (including the Corvette) and some light duty pickups, often behind the 6 liter V8. It was selected for its durability, low weight, and the ability to optimize its electronic controls for performance oriented shifting. The electronic controls are calibrated to give the dependability of a pickup and the performance of a supersport vehicle. (In 2005, the 4L65-E replaced the 4L60-E, and a manual became available.)
To multiply engine torque the 4L60-E uses a 300 millimeter torque converter. The converter is enclosed in 360 degree-mount structural bell housing for powertrain rigidity. Overall transmission weight as shipped from the Toledo, Ohio, transmission assembly plant is 88.3 kilograms (194.6 pounds).
The SSR features a TORSEN Traction Differential on the rear axle. The TORSEN differential distributes the engine’s power to the wheel with the most traction, reacting instantly before any wheel slip can occur. The TORSEN system for the SSR is a close relative to the rear differential developed for the Chevrolet Camaro and is the technology of choice for numerous racing teams.
"The TORSEN differential will work seamlessly with the standard traction control system to give the SSR strong performance in driving manuevers such as aggressive acceleration and cornering and the wide variety of road conditions," said Ted Robertson, Chief Engineer for the Chevy SSR.
The Chevy SSR features an engine-based electronic traction control to manage the level of power, while the Torsen differential provides an extra measure of traction with its precise distribution of power. The rear axle ratio for the SSR will be 3.73:1.
An axle differential is located on the rear (rear wheel drive) or front axles (front wheel drive), and distributes the engine’s power to the wheels. Most are passive in design, relying on clutches and the inertia of wheel-spin to engage and transfer power to the wheel with the most traction. TORSEN units employ a gearing system that reacts faster. An advanced gearing system senses torque or force feedback from a wheel that is about to slip or skid, and shifts most of the engine’s power away - prior to wheel slip - to the wheel with the most traction.
The torque distributing effect of the TORSEN differential is a constant, proportional to the torque on the axle. With minimum torque on the axle, differentiation occurs freely as with an open differential making it easier to maneuver when both rear wheels are on a slippery surface. When operating the vehicle with unequal traction under the rear wheels, the TORSEN differential will apply about 65-70 percent of the total axle torque to the wheel with the greater traction.
The SSR’s handling characteristics will benefit from the TORSEN differential, as well. In a cornering manuever, the differential will bias torque to the outside wheel after the inside wheel becomes saturated with torque and begins to slip. The result is smooth handling, strong traction and quicker and safer lane changes.
The TORSEN system is manufactured by Zexel TORSEN of Rochester, N.Y., a subsidiary of Robert Bosch, Inc.