Which Pontiac GTO Version Should You Buy?
The Pontiac GTO catalogue covers four generations and eleven listed versions, but the best choice depends on whether you want the strongest performance, the lightest documented power-to-weight ratio, an Automatic, a Manual, or an earlier carbureted Cabrio.
The Pontiac GTO catalogue covers four generations and eleven listed versions, but the best choice depends on whether you want the strongest performance, the lightest documented power-to-weight ratio, an Automatic, a Manual, or an earlier carbureted Cabrio. The standout performance choice is the fourth-generation 6.0 AT: it combines 400 hp and 542 Nm with a 5-second 0–100 km/h time, 255 km/h top speed, and the lowest measured fuel consumption among the versions with economy data. The 6.0 MT offers the same output with a 6-speed Manual, while the first-generation 6.6 MT and 6.6 AT lead the earlier cars with 365 hp and 594 Nm. Buyers prioritizing the lowest documented kerb weight should compare the fourth-generation 5.7 MT and 5.7 AT, both at 1,650 kg.
Pontiac GTO generations: what changed?
The first generation ran from 1964 to 1967 as a Cabrio and contains three versions: 6.4 MT, 6.6 MT, and 6.6 AT. All use naturally aspirated, carbureted Gasoline V-shaped 8-cylinder engines with RWD. The 6.4 MT produces 330 hp and 580 Nm, while both 6.6 versions raise output to 365 hp and 594 Nm. A buyer can therefore choose the 6.6 MT for a 4-speed Manual or the 6.6 AT for a 3-speed Automatic without sacrificing listed power or torque.
The second generation covers 1968–1973 and is also a Cabrio, with two versions: 6.4 AT and 6.6 AT. Both have a naturally aspirated, carbureted Gasoline V-shaped 8-cylinder engine, a 3-speed Automatic, and RWD. The 6.4 AT makes 325 hp from 6,400 cc, whereas the 6.6 AT makes 335 hp from 6,600 cc. Choosing the larger engine adds 200 cc and 10 hp; torque and measured performance figures are not available for either version.
The third generation is the 1974 Liftback, offered as 5.7 MT and 5.7 AT. Each version uses a 5,700 cc naturally aspirated, carbureted Gasoline V-shaped 8-cylinder engine producing 200 hp and 400 Nm. Both are RWD with a 3-speed gearbox, so the meaningful choice is between Manual and Automatic. Acceleration, top speed, fuel consumption, kerb weight, fuel-tank capacity, and ground clearance are not measured.
The fourth generation ran from 2004 to 2006 as a Coupe and offers four versions: 5.7 MT, 5.7 AT, 6.0 AT, and 6.0 MT. It retains naturally aspirated Gasoline V-shaped 8-cylinder engines and RWD but changes from the earlier generations’ Carburetor to Distributed injection (multi-point). The 5.7 versions produce 350 hp and 495 Nm, while the 6.0 versions produce 400 hp and 542 Nm. Moving from the 5.7 to the 6.0 therefore adds 302 cc, 50 hp, and 47 Nm.
Pontiac GTO engine options and specs
| Generation and version | Displacement | Power | Torque | Fuel | Cylinders and layout | Boost | Gearbox | Drive |
|---|---|---|---|---|---|---|---|---|
| 1964–1967 6.4 MT | 6,362 cc | 330 hp | 580 Nm | Gasoline | 8, V-shaped | No | 4-speed Manual | RWD |
| 1964–1967 6.6 MT | 6,554 cc | 365 hp | 594 Nm | Gasoline | 8, V-shaped | No | 4-speed Manual | RWD |
| 1964–1967 6.6 AT | 6,554 cc | 365 hp | 594 Nm | Gasoline | 8, V-shaped | No | 3-speed Automatic | RWD |
| 1968–1973 6.4 AT | 6,400 cc | 325 hp | not measured | Gasoline | 8, V-shaped | No | 3-speed Automatic | RWD |
| 1968–1973 6.6 AT | 6,600 cc | 335 hp | not measured | Gasoline | 8, V-shaped | No | 3-speed Automatic | RWD |
| 1974 5.7 MT | 5,700 cc | 200 hp | 400 Nm | Gasoline | 8, V-shaped | No | 3-speed Manual | RWD |
| 1974 5.7 AT | 5,700 cc | 200 hp | 400 Nm | Gasoline | 8, V-shaped | No | 3-speed Automatic | RWD |
| 2004–2006 5.7 MT | 5,665 cc | 350 hp | 495 Nm | Gasoline | 8, V-shaped | No | 6-speed Manual | RWD |
| 2004–2006 5.7 AT | 5,665 cc | 350 hp | 495 Nm | Gasoline | 8, V-shaped | No | 4-speed Automatic | RWD |
| 2004–2006 6.0 AT | 5,967 cc | 400 hp | 542 Nm | Gasoline | 8, V-shaped | No | 4-speed Automatic | RWD |
| 2004–2006 6.0 MT | 5,967 cc | 400 hp | 542 Nm | Gasoline | 8, V-shaped | No | 6-speed Manual | RWD |
Power per litre clarifies what the displacement increase buys. The first-generation 6.4 MT develops about 51.9 hp per litre, compared with about 55.7 hp per litre for its 6.6 MT and 6.6 AT alternatives. The second-generation 6.4 AT and 6.6 AT deliver about 50.8 hp per litre in each case. Both third-generation 5.7 versions produce about 35.1 hp per litre. In the fourth generation, the 5.7 MT and 5.7 AT reach about 61.8 hp per litre, while the 6.0 AT and 6.0 MT rise to about 67.0 hp per litre.
Pontiac GTO performance and fuel economy
| Generation and version | 0–100 km/h | Top speed | City | Highway | Combined |
|---|---|---|---|---|---|
| 1964–1967 6.4 MT | 6.9 s | 196 km/h | not measured | not measured | not measured |
| 1964–1967 6.6 MT | not measured | not measured | not measured | not measured | not measured |
| 1964–1967 6.6 AT | not measured | not measured | not measured | not measured | not measured |
| 1968–1973 6.4 AT | not measured | not measured | not measured | not measured | not measured |
| 1968–1973 6.6 AT | not measured | not measured | not measured | not measured | not measured |
| 1974 5.7 MT | not measured | not measured | not measured | not measured | not measured |
| 1974 5.7 AT | not measured | not measured | not measured | not measured | not measured |
| 2004–2006 5.7 MT | 6 s | 257 km/h | not measured | not measured | not measured |
| 2004–2006 5.7 AT | 6 s | 257 km/h | not measured | not measured | not measured |
| 2004–2006 6.0 AT | 5 s | 255 km/h | 12.5 L/100 km | 8.5 L/100 km | 11 L/100 km |
| 2004–2006 6.0 MT | 5.2 s | 255 km/h | 14.7 L/100 km | 11.2 L/100 km | 13 L/100 km |
The 6.0 AT is 0.2 seconds quicker to 100 km/h than the 6.0 MT and uses 2.2 L/100 km less in the city, 2.7 L/100 km less on the highway, and 2 L/100 km less on the combined cycle. The 5.7 MT and 5.7 AT are each 1 second slower to 100 km/h than the 6.0 AT, although their listed top speed is 2 km/h higher. Fuel economy for both 5.7 versions is not measured, so no consumption comparison with the 6.0 versions can be made.
Pontiac GTO dimensions, weight, clearance, and tank size
Overall length, width, wheelbase, gross weight, and wheel sizes are not measured for any listed Pontiac GTO version. Kerb weight and ground clearance are measured only for the fourth generation. The 5.7 MT and 5.7 AT weigh 1,650 kg each, while the 6.0 AT and 6.0 MT weigh 1,720 kg each. Thus, the 6.0 versions add 70 kg alongside their extra 50 hp and 47 Nm.
Despite weighing more, the 6.0 AT and 6.0 MT have the better calculated weight-to-power figure at 4.30 kg per hp. The 5.7 MT and 5.7 AT carry about 4.71 kg per hp. This means the additional output more than offsets the additional kerb weight on a simple kilograms-per-horsepower comparison.
All fourth-generation versions provide 198 mm of ground clearance and a 70-litre fuel tank. The first-generation 6.4 MT, 6.6 MT, and 6.6 AT each have an 82-litre tank, but their kerb weight, gross weight, ground clearance, and wheel sizes are not measured. Tank capacity, weight, clearance, and wheel sizes for the second and third generations are not measured.
Which Pontiac GTO version should you choose?
Choose the 2004–2006 6.0 AT if measured straight-line performance and fuel economy matter most. Its 400 hp, 542 Nm, 5-second 0–100 km/h result, and 11 L/100 km combined consumption make it the strongest all-round numerical package in the catalogue. It also has the same 1,720 kg kerb weight and 255 km/h top speed as the 6.0 MT.
Choose the 2004–2006 6.0 MT if a 6-speed Manual is the priority. It matches the 6.0 AT’s 400 hp and 542 Nm, but reaches 100 km/h 0.2 seconds later and records 2 L/100 km higher combined consumption. The choice is therefore about gearbox preference rather than additional engine output.
Choose the 2004–2006 5.7 MT or 5.7 AT if lower documented weight matters more than maximum power. Both weigh 70 kg less than the 6.0 versions and produce 350 hp and 495 Nm. Their performance is identical at 6 seconds to 100 km/h and 257 km/h, leaving the 6-speed Manual versus 4-speed Automatic as the deciding factor. Their fuel consumption is not measured.
Among the first-generation cars, choose the 6.6 MT or 6.6 AT for the highest earlier-generation output: both provide 35 hp and 14 Nm more than the 6.4 MT. Choose the 6.6 MT for a 4-speed Manual or the 6.6 AT for a 3-speed Automatic. The 6.4 MT remains the only first-generation version with measured performance, at 6.9 seconds to 100 km/h and 196 km/h.
Within the second generation, the 6.6 AT buys 10 hp over the 6.4 AT while keeping the same 3-speed Automatic and RWD layout. Within the 1974 third generation, the 5.7 MT and 5.7 AT have identical 200 hp and 400 Nm outputs, so the purchase decision comes down to Manual or Automatic. Because performance, economy, and weight are not measured for these versions, a more detailed numerical ranking would not be supported by the catalogue data.