GTO – the original muscle car – was re-introduced last year and returns with more power and style for 2005. A new LS2 6.0L V-8 engine replaces the LS1 5.7L engine, bringing with it an increase in horsepower and torque.
The ’05 GTO packs 400 horsepower (295 kw) – up from 350 horses (261 kw) – and 395 lb.-ft. of torque (546 Nm), up from 365 lb.-ft. (495 Nm). Transmission choices are the same as the ’04 model’s: The Hydra-Matic 4L60-E four-speed automatic is standard and the Tremec six-speed manual is optional. GTO’s more powerful engine should lower the 0-60 time to less than 5 seconds.
Enthusiasts will immediately spot the brawnier ’05 GTO, thanks to new badging and a revised rear fascia that incorporates a new dual-exhaust system – it splits the GTO’s two outlets, routing them to opposite sides of the rear fascia. The exhaust tips are polished for a more refined appearance.
Also available is a new hood design incorporating a pair of stylish air scoops. The scoops draw fresh air in to the GTO’s engine compartment.
The badges identifying the ’05 GTO’s bigger V-8 include a “6.0” badge on the trunk lid and revised “GTO” fender badges, which now incorporate “6.0 Litre” designations. The original 1964 GTO also wore “6.0 Litre” fender badges, but at a time when almost every other American manufacturer referenced engine size in cubic inches. Along with the GTO’s power increase comes improved braking performance from larger brake rotors, calipers and pads. The calipers are painted red and the front calipers feature the GTO logo.
Additional changes to the ’05 GTO include two new colors (blue and grey), as well as driver foot rest. A line of regular production accessories (RPAs) based on the 2004 GTO Performance Plus SEMA concept vehicle is scheduled for start-of-production availability. The accessories include a tall rear spoiler, front and rear fascia extensions, rocker molding extensions and grille inserts. As part of GM’s RPA program, the accessories can be ordered and installed on the vehicle prior to delivery.
LS2 DetailsCompared to the Gen III-based LS1, the 2005 GTO’s LS2 V-8 incorporates several significant changes to help improve performance. The block is an all-new casting with cylinder bores measuring 4.00 inches (101.6 mm) in diameter. The cylinder heads and camshaft are revised, too, to deliver the airflow necessary to complement the engine’s larger displacement. Other changes include:
- New aluminum block casting with revised oil galleries and provisions for external knock sensors – external sensors improve serviceability
- Camshaft lift increased to take advantage of increased cylinder head flow
- Camshaft sensor relocated from the rear of the block to the front of the block provides room for new oil galleries
- Flat-top piston design with lower ring tension reduces friction
- Piston floating wrist pins help quiet the engine
- More efficient ignition coils require less energy to provide a comparable spark
- Compression raised to 10.9:1
- Larger, 90-mm single-blade throttle body
- Reduced-mass water pump design with improved sealing capability
- Engine “redline” raised to 6500 rpm
- Revised and more powerful engine controller incorporates all electronic throttle control functions
Balanced Environment and Safety
The new GTO is a contemporary performer. Its traits include impressive cornering abilities, a smooth ride and surprising comfort. The drivetrain rides on a 109.8-inch (279-cm) wheelbase, with a low stance that enhances the wide-track feel behind the wheel. The front track measures 61.4 inches (156 cm) and the rear track is 62.1 inches (158 cm) wide.
The fully independent suspension features MacPherson struts in front and a semi-trailing arm design in the rear, with specially tuned strut valving and spring rates. Direct-acting stabilizer bars and a variable ratio power steering system also are tuned to provide a sporty feel and increased driver feedback. Seventeen-inch alloy wheels and performance tires are matched to the performance-tuned suspension. Traction control and a limited slip differential also come standard.
The GTO’s premium interior is accented by a harmonious blend of details, complementing its dynamic driving experience. All-leather seating, as well as a leather-covered steering wheel and shifter knob, immediately conveys luxury, while items such as stainless steel sill plates, metallic-look steering wheel styling, satin nickel-look accent trim, and racing-inspired drilled metallic pedals add sportiness to the environment.
The front and rear sports seats are configured in a traditional 2+2 configuration, with side bolsters and the “GTO” name embroidered on the front seats. Interior seat and trim colors may be coordinated to the exterior color, with red, blue, purple and black interiors available. This splash of color extends from the seats to the door inserts to the lower part of the instrument panel to the gauge cluster.
