Which Buick GS version to buy: 7.5 AT vs 7.5 MT

There is only 1 generation of the Buick GS in this dataset, sold from 1970-01-01 to 1972-12-31, body Cabrio, 2 versions. No second generation exists here to “upgrade into,” and no restyling is listed as a separate generation.

There is only 1 generation of the Buick GS in this dataset, sold from 1970-01-01 to 1972-12-31, body Cabrio, 2 versions. No second generation exists here to “upgrade into,” and no restyling is listed as a separate generation. A buyer is not choosing among years of architecture; the two cars share displacement, power, torque, layout, drive, kerb weight, tank, ground clearance, and the published 0–100 and top-speed figures. The decision is 7.5 AT versus 7.5 MT.

Search queries often mix this GS with GSX, Stage 1, 455, 400, 350, and later Regal GS names. Those names are not version keys in this data. The only named versions are 7.5 AT and 7.5 MT. Specs below apply only to those two.

Buick GS generations compared: what 1 generation actually changes

1 generation (1970–1972), Cabrio, 2 versions. Production window is three calendar years with the same start and stop on both versions: 1970-01-01 to 1972-12-31. Body type does not change between versions. Engine count of cylinders is 8, arrangement V-shaped, valves per cylinder 2, feed Carburetor, position Front, longitudinal, boost not measured, compression 10, bore × stroke 109.5 × 99.1.

Because there is one generation, there is no arithmetic “gen 2 gained X hp” or “gen 3 lost Y kg.” Year-to-year horsepower splits (1970 vs 1971 vs 1972) are not measured as separate rows. If a listing is labelled 1970, 1971, or 1972 Buick GS, map it to these two versions, not to extra catalogue lines.

Buick GS specs table: both versions side by side

VersionhpkWrpm (power)Nmrpm (torque)Displacement (cm³)FuelCylindersLayoutBoostGearboxGearsDrive
7.5 AT355261460069128007466Gasoline8V-shapednot measuredAutomatic3RWD
7.5 MT355261460069128007466Gasoline8V-shapednot measuredManual4RWD

Power, torque, displacement, fuel, cylinders, layout, boost, and drive are identical. Gearbox is Automatic vs Manual. Gear count is 3 vs 4 — one extra ratio on 7.5 MT.

Buick GS engine: same 7466 cm³ on 7.5 AT and 7.5 MT

Both versions are a 7466 cm³ Gasoline engine, 8 cylinders, V-shaped, 2 valves per cylinder, Carburetor, compression 10, Front, longitudinal. Boost is not measured. Fuel grade is not measured.

Specific output:

Displacement in litres is 7466 ÷ 1000 = 7.466 L. There is no second engine size in this catalogue, so there is no 400 vs 455 vs 350 choice among these rows. Engine “options” here are one engine and two gearboxes.

Peak power is at 4600 rpm; peak torque at 2800 rpm. The gap is 1800 rpm. Torque arrives 1800 rpm earlier than peak power on both versions.

Buick GS horsepower and weight: kg per hp is the same

Kerb weight is 1757 kg on 7.5 AT and 1757 kg on 7.5 MT. Difference: 0 kg. Gross weight is not measured on both.

Ground clearance is 163 mm on both. Tank is 76 L on both. Wheel sizes are not measured. Front suspension Independent, spring; rear Dependent, spring. Front brakes Drum. Rear brakes not measured.

A heavier or lighter “1970 Buick GS weight” versus “1969” is not measured here; kerb is 1757 kg for both listed versions.

Buick GS performance and mpg: 0–100, top speed, consumption

Version0–100 km/h (s)Top speed (km/h)CityHighwayCombinedCO2Eco class
7.5 AT5.5233not measurednot measurednot measurednot measurednot measured
7.5 MT5.5233not measurednot measurednot measurednot measurednot measured

0–100 is 5.5 s on both; difference 0.0 s. Top speed is 233 km/h on both; difference 0 km/h. Mean acceleration implied by 0–100 in 5.5 s is 100 ÷ 5.5 ≈ 18.2 km/h per second on both.

Fuel consumption (city, highway, combined) is not measured. Do not infer mpg from tank size. Tank 76 L is capacity, not use. Range is not measured.

The extra gear on 7.5 MT (4 vs 3) does not come with a different 0–100 or top-speed figure in this data. Buying 7.5 MT for a published acceleration advantage is not supported: the numbers are equal.

Dimensions and weight: what is measured, what is not

Measured on both 7.5 AT and 7.5 MT:

Not measured on both:

If a search is “1970 Buick GS dimensions,” this dataset answers weight, clearance, and tank, not exterior millimetres.

Which version to choose: 7.5 AT or 7.5 MT

Use the numbers that differ.

Choose 7.5 AT if the gearbox is the point. It is Automatic, 3 gears, RWD. Power 355 hp, torque 691 Nm, 0–100 5.5 s, top speed 233 km/h, kerb 1757 kg, tank 76 L, clearance 163 mm — the same as the manual. You are not paying (in spec terms) for more horsepower or a lighter body. You are choosing 3 Automatic ratios instead of 4 Manual ratios. Gear count is 1 lower than 7.5 MT.

Choose 7.5 MT if the extra ratio and Manual control are the point. It is Manual, 4 gears, RWD. Same 355 hp, 261 kW, 691 Nm, 7466 cm³, 5.5 s, 233 km/h, 1757 kg. You get +1 gear versus 7.5 AT. You do not get a second engine, a different body, or a different generation. 0–100 and top speed stay 5.5 s and 233 km/h.

What the “extra” does not buy. Between these two versions:

Prices are not in this dataset. “What the extra money buys” in money is not measured. In specification, the extra is 1 gear and Manual versus Automatic.

GSX, Stage 1, 455, 400, 350, Regal GS. Those strings appear in search, not as `mod_name` here. Do not treat this article’s 7.5 AT / 7.5 MT as a GSX Stage 1 or a Regal GS engine table. If a car is a different name, it is outside these two rows.

Reliability and problems: what this catalogue does not measure

Problem lists, failure rates, and reliability scores are not measured. Consumption, CO2, and eco class are not measured, so economy-based “which to buy for mpg” cannot be ranked. Rear brakes are not measured; front are Drum on both. Wheel sizes are not measured. Gross weight is not measured, so payload is not measured.

What is measured and equal should not be sold as a reliability difference: same displacement, same hp, same kerb, same years.

Short buyer rule