These are the standard painted aluminum 18x8-inch wheels and 245/45-18 all-season tires for the base six.
| 2008 Pontiac G8 And G8 GT Specifications |
| Overview |
| Models | Pontiac G8 ($27,595) and G8 GT ($29,995) |
| Construction | Unitized body frame, 1- and 2-sided galvanized steel |
| Manufacturing Location | Adelaide, Australia |
| Transmission (Hydra-Matic) |
| | First | Second | Third | Fourth | Fifth | Sixth | Reverse |
| 5L40 Five-Speed Auto: | 3.42 | 2.21 | 1.60 | 1.00 | 0.75 | N/A | 3.02 |
| 6L80 Six-Speed Auto (MYC): | 4.03 | 2.36 | 1.53 | 1.15 | 0.85 | 0.67 | 3.06 |
| Final Drive Ratio | | | Five-speed: 2.92; Six-speed: 2.92 | | |
The GT's machined face aluminum wheelss are shod with 245/45-18 summer tires. A set of 19-inch wheels and tires are optional.
| Engines |
| | 3.6L V-6 (LY7) | 6.0L V-8 (L76) |
| Application: | G8 | G8 GT |
| Type: | 3.6L V-6 | 6.0L V-8 |
| Displ. (cu in/cc): | 217/3,564 | 364/5,967 |
| Bore/Stroke (in): | 3.70x3.37 | 3.99x3.62 |
| Block Material: | Cast aluminum with cast-in-place iron bore liners | Same |
| Cylinder Head Material: | Aluminum | Same |
| Valvetrain: | Dual overhead camshafts, 4 valves per cylinder, continuously variable valve timing | Valve-in-head; 2 valves per cylinder,roller lifters, 1.7:1 rockers |
| Cam: | N/A | 200/208-deg duration at 0.050, 0.472/0.480 lift |
| Fuel Delivery: | Returnless, sequential fuel injection | Returnless, sequential fuel injection; active fuel-management system |
| Induction System: | N/A | 90mm electronic throttle body, high-flow composite intake with acoustic shell, 5.0 g/s static flow injectors |
| Ignition System: | Electronic individual coil-on-plug; individual cylinder knock control and extended-life spark plugs | High-energy distributorless ignition; solid-state direct-fire ignition with coil near plug and integrated ignition; extended-life spark plugs |
| Compression Ratio: | 10.2:1 | 10.4:1 |
| Horsepower (hp at rpm): | 256 at 6,300 | 361 at 5,300 |
| Torque (lb-ft at rpm): | 248/335 at 2,100 | 385/520 at 4,400 |
| Recommended Fuel: | Regular unleaded (premium maximizes performance) | Same |
| Maximum Engine Speed (rpm): | 6,900 | 6,000 |
| Exhaust: | N/A | 4-2-1 design, 5-bolt inlet flange, with unequal-length primaries and equal-length secondaries merging into one outlet with a counter bore flange. Dual Closed Couple Cats, 4-pipe exhaust outlet with round chrome tips |
| Estimated Fuel Economy: | 17 city/25 highway | 15 city/24 highway |