Buick Century

Buick Century: generations compared: what actually changed

The generation that changes the buying decision is the step from 4 generation (1978–1982, Coupe, RWD, Carburetor, 3-speed Automatic) to 5 generation (1982–1996, Coupe, FWD, Distributed injection (multi-point) on the gasoline cars). Drive flips from RWD to FWD. Fuel feed flips from Carburetor to injection (except the 5 generation 4.3 AT Diesel, where the feed system is not measured).

The generation that changes the buying decision is the step from 4 generation (1978–1982, Coupe, RWD, Carburetor, 3-speed Automatic) to 5 generation (1982–1996, Coupe, FWD, Distributed injection (multi-point) on the gasoline cars). Drive flips from RWD to FWD. Fuel feed flips from Carburetor to injection (except the 5 generation 4.3 AT Diesel, where the feed system is not measured). Boost disappears as a catalogue option: the only Turbo in the entire line is 4 generation 3.8 AT at 172 hp / 359 Nm. Rear brakes stay Drum through 5 generation and become Disc only in 6 generation. Rear suspension is Independent, spring in 5 generation and Dependent, spring in 6 generation. Ground clearance is 160 mm wherever it is measured (5 and 6 generation); it is not measured in 3 and 4 generation. Wheel sizes are not measured on any version.

Tank size is a generation fingerprint: 68 L in 4 generation, 63 L in 5 generation (−5 L), 66 L in 6 generation (+3 L vs 5 generation, −2 L vs 4 generation). Tank capacity is not measured in 3 generation.

Kerb weight, where it exists, rose as the car moved from Coupe to Sedan: 1358–1419 kg in 5 generation, 1515–1550 kg in 6 generation. That is +157 kg from the lightest 5 generation car (1358 kg) to the lightest 6 generation 3.1 AT (1515 kg), and +192 kg to the 177 hp 3.1 AT (1550 kg). Gross weight is measured only on 6 generation, both 3.1 AT versions: 2026 kg. Payload on the arithmetic is 511 kg for the 162 hp car (2026 − 1515) and 476 kg for the 177 hp car (2026 − 1550).

Specs table: every named version

Exact names as in the database. Duplicate names are split by power (and, where power matches, by gears, kerb weight, or front brakes).

6 generation, 1997–2005, Sedan, FWD, Automatic, 4 gears, Gasoline, 6, V-shaped, 2 valves/cyl, boost No, Front, transverse, Distributed injection (multi-point), fuel 92

Compression and bore × stroke: not measured on the 162 hp 3.1 AT; 9.6 and 89 × 84 on the 177 hp 3.1 AT. CO2 and eco class: not measured. Wheels: not measured. Front brakes Disc, rear Disc. Clearance 160 mm.

5 generation, 1982–1996, Coupe, FWD, Automatic, Gasoline unless noted, boost No, clearance 160 mm, tank 63 L, gross not measured, 0–100 not measured, consumption not measured, wheels not measured, engine location not measured

Fuel on the gasoline 5 generation cars is 95; the 4.3 AT is Diesel. Valves per cylinder: 2 except 4.3 AT (not measured). Feed: Distributed injection (multi-point) except 4.3 AT (not measured). Compression 9.0 on the 2.2 / 2.5 / 2.8 / 3.3 cars; 9.5 on 3.0 AT; 9.6 on 3.8 AT and 3.1 AT; not measured on 4.3 AT. Bore × stroke 89 × 88 on the 2.2 / 2.5 / 2.8 / 3.3; 89 × 80 on 3.0 AT; 89 × 84 on 3.8 AT and 3.1 AT; not measured on 4.3 AT. Rear brakes Drum on all 12. Top speed: not measured except 3.1 AT 160 hp at 195 km/h.

4 generation, 1978–1982, Coupe, RWD, Automatic 3 gears, Carburetor, 2 valves/cyl, tank 68 L, kerb / gross / clearance / wheels / 0–100 / vmax / consumption / fuel grade / CO2 / eco / rear suspension: not measured

Front brakes Disc, rear Drum.

3 generation, 1973–1977, Coupe, RWD, Automatic 3 gears, Carburetor, 6 or 8 V-shaped, 2 valves/cyl, boost No. Tank, kerb, gross, clearance, wheels, 0–100, vmax, consumption, fuel grade, compression, bore, CO2, eco, engine location, rear suspension: not measured

Front brakes Disc, rear Drum.

Engines: power per litre and what the extra displacement buys

Specific output (hp per litre of the listed displacement) is the cleanest way to rank engines that never share a 0–100 figure.

6 generation. 162 hp 3.1 AT: 162 / 3.125 = 51.8 hp/L. 177 hp 3.1 AT: 177 / 3.135 = 56.5 hp/L. The 10 cc gap (3135 − 3125) is 0.3% of displacement and comes with +15 hp (+9.3%) and +13 Nm (+5.2%). Torque density: 251 / 3.125 = 80.3 Nm/L vs 264 / 3.135 = 84.2 Nm/L.

5 generation gasoline. Highest specific power among the listed cars is the 122 hp 2.2 AT at 122 / 2.190 = 55.7 hp/L — within 0.8 hp/L of the later 177 hp 3.1. The 115 hp 2.2 AT is 52.5 hp/L. 3.1 AT 160 hp: 160 / 3.136 = 51.0 hp/L. 3.3 AT 160 hp: 160 / 3.300 = 48.5 hp/L — same 160 hp as the 3.1, 164 cc more, 2.5 hp/L less. 2.8 AT 125 hp: 44.8 hp/L. 2.5 AT 110 hp: 44.0 hp/L. 3.8 AT 150 hp: 39.5 hp/L despite 270 Nm, the highest gasoline torque in 5 generation. 3.0 AT 110 hp: 36.9 hp/L and the lowest gasoline torque in the generation (145 Nm). 2.5 AT 90 hp: 36.0 hp/L, the weakest gasoline output. 4.3 AT Diesel: 85 / 4.300 = 19.8 hp/L, the lowest specific power in the whole model, with 224 Nm — more torque than the 2.2 (176 Nm) and 3.0 AT (145 Nm), less than 2.8 AT (197 Nm).

Same peak power, different engine: 5 generation 3.3 AT and 3.1 AT both make 160 hp / 118 kW / 251 Nm. The 3.3 is 4 Inline at 3300 cc; the 3.1 is 8 V-shaped at 3136 cc. The 3.1 is 34 kg heavier (1392 vs 1358) and is the only 5 generation car with a measured top speed (195 km/h). If 160 hp is the target, the 3.3 AT is the lighter, simpler cylinder count; the 3.1 AT is the one with a speed figure and the 8-cylinder layout.

4 generation. Turbo is the entire story. Naturally aspirated 3.8 AT 112 hp: 29.5 hp/L and 68.1 Nm/L. Turbo 3.8 AT 172 hp: 45.4 hp/L and 94.7 Nm/L on the same 3791 cc and the same 8.1 compression. That is +60 hp (+53.6%) and +101 Nm (+39.1%) from Turbo vs No, with peak torque 800 rpm higher (2400 vs 1600). The Turbo 3.8 also beats every larger 4 generation V-shaped 8 on power: 4.3 AT 122 hp (28.1 hp/L), 4.9 AT 142 hp (28.7 hp/L), 5.0 AT 157 hp (31.4 hp/L), 5.7 AT 162 hp (28.3 hp/L). Torque: Turbo 359 Nm vs 5.7 AT 353 Nm — 6 Nm more from 1933 cc less (5724 − 3791). The 5.7 still makes 353 / 5.724 = 61.7 Nm/L, well below the Turbo’s 94.7. If 4 generation is the hunt, the 172 hp 3.8 AT is the version the numbers justify; the 112 hp 3.8 AT is the same displacement without the boost. The 8-cylinder cars buy displacement and low-rpm torque (4.3 AT 285 Nm @ 1800, 4.9 AT 325 Nm @ 1800, 5.0 AT 325 Nm @ 1600) at 28–31 hp/L.

3 generation. Same nameplates as the bookends of 4 generation, without Turbo and without the 4.3 / 4.9 / 5.0. 3.8 AT 112 hp makes 237 Nm @ 2000 vs 258 Nm @ 1600 on the later 112 hp 3.8 AT — 21 Nm less, 400 rpm later. 5.7 AT 162 hp is numerically identical in both generations (162 hp / 119 kW @ 3800, 353 Nm @ 2200, 5724 cc). The extra money in 4 generation, on these two names, buys a 21 Nm bump on the 3.8 and a 68 L tank (3 generation tank not measured). The Turbo 3.8 and the 4.3 / 4.9 / 5.0 appear only in 4 generation.

Performance and economy

Measured 0–100 km/h exists only on 6 generation: 9.2 s (162 hp 3.1 AT) and 9.3 s (177 hp 3.1 AT). The stronger engine is 0.1 s slower; kerb weight is 35 kg higher (2.3%). Top speed exists on three cars: 175 km/h (162 hp 6 generation 3.1 AT), 195 km/h (177 hp 6 generation 3.1 AT), 195 km/h (5 generation 3.1 AT 160 hp). The 177 hp sedan and the 160 hp 5 generation Coupe share 195 km/h; the 162 hp sedan is 20 km/h slower. Every other vmax is not measured.

Fuel consumption is measured only on both 6 generation 3.1 AT cars: 11.8 / 8.1 / 9.8 L/100 km city / highway / mixed. The 15 hp does not show up in the fuel row. Fuel 92 vs 95 is a generation split: 6 generation 92, 5 generation gasoline 95. 3 and 4 generation fuel grade is not measured. CO2 and eco class are not measured on any version.

Range arithmetic on mixed 9.8 L/100 km and 66 L: 66 / 9.8 × 100 ≈ 673 km if mixed use holds. 5 generation tank is 63 L with consumption not measured, so range is not measured. 4 generation tank is 68 L with consumption not measured.

Dimensions and weight

Wheel sizes: not measured, all versions.

Ground clearance: 160 mm on every 5 and 6 generation version; not measured on 3 and 4 generation.

Kerb weight clusters:

• 1358 kg: ten of twelve 5 generation versions (both 2.2 AT 115 hp, 2.2 AT 122 hp / 1358 kg, both 2.5 AT, 2.8 AT, 3.0 AT, 3.3 AT, 3.8 AT, 4.3 AT).
• 1392 kg: 5 generation 3.1 AT 160 hp (+34 kg vs 1358).
• 1419 kg: 5 generation 2.2 AT 122 hp with Ventilated disc (+61 kg vs the 1358 kg 122 hp 2.2 AT). Same 122 hp, same 176 Nm, same 3 gears, 61 kg more — 11.63 vs 11.13 kg/hp. Buy the 1358 kg 2.2 AT 122 hp unless the Ventilated disc front is the point.
• 1515 kg: 6 generation 3.1 AT 162 hp.
• 1550 kg: 6 generation 3.1 AT 177 hp.

3 and 4 generation kerb and gross: not measured. 5 generation gross: not measured.

Weight per horsepower (kerb / hp), where kerb exists:

• 6 generation 177 hp 3.1 AT: 8.76 kg/hp (best in the model among cars with a kerb figure).
• 6 generation 162 hp 3.1 AT: 9.35 kg/hp.
• 5 generation 3.3 AT 160 hp: 8.49 kg/hp (1358 / 160) — lighter per hp than either 6 generation 3.1 because the Coupe is 157–192 kg lighter.
• 5 generation 3.1 AT 160 hp: 8.70 kg/hp (1392 / 160).
• 5 generation 3.8 AT 150 hp: 9.05 kg/hp.
• 5 generation 2.8 AT 125 hp: 10.86 kg/hp.
• 5 generation 2.2 AT 122 hp at 1358 kg: 11.13 kg/hp; at 1419 kg: 11.63 kg/hp.
• 5 generation 2.2 AT 115 hp: 11.81 kg/hp.
• 5 generation 2.5 AT 110 hp and 3.0 AT 110 hp: 12.35 kg/hp.
• 5 generation 2.5 AT 90 hp: 15.09 kg/hp.
• 5 generation 4.3 AT 85 hp: 15.98 kg/hp (worst).

Payload (gross − kerb) is only computable on 6 generation: 511 kg vs 476 kg. The 162 hp 3.1 AT carries 35 kg more payload, equal to its kerb advantage.

Which version to choose

Daily sedan with measured performance and economy. 6 generation 3.1 AT, and specifically the 177 hp car if the goal is power, top speed, and kg/hp. Fuel, gears (4), drive (FWD), layout (Front, transverse, 6 V-shaped, boost No), tank (66 L), clearance (160 mm), and mixed 9.8 L/100 km do not change. Pick the 162 hp 3.1 AT only if the 35 kg, the 511 kg payload, or the 0.1 s 0–100 matters more than 15 hp and 20 km/h. Rear suspension on both is Dependent, spring — that is the chassis difference vs every listed 5 generation Coupe (Independent, spring rear).

Most power in the whole catalogue. 4 generation 3.8 AT 172 hp Turbo (126 kW, 359 Nm). Nothing else reaches 172 hp or 359 Nm. It is RWD, Carburetor, 3 gears, Coupe, kerb not measured, 0–100 not measured, consumption not measured. It is the opposite of the 6 generation sedan on every drivetrain axis except Automatic.

Most torque without Turbo. 4 generation 5.7 AT and 3 generation 5.7 AT, both 353 Nm @ 2200, 162 hp, 5724 cc, 8 V-shaped. 4 generation adds a 68 L tank; 3 generation tank is not measured. Next gasoline torque is 4 generation 4.9 AT / 5.0 AT at 325 Nm, then 4 generation 4.3 AT at 285 Nm, then 5 generation 3.8 AT at 270 Nm.

Lightest cars. Any 5 generation version at 1358 kg. Among those, 3.3 AT 160 hp is the highest power at that weight (8.49 kg/hp). 3.8 AT 150 hp is the torque pick at that weight (270 Nm). 2.8 AT 125 hp is the only 4-cylinder V-shaped at 1358 kg. Avoid 2.5 AT 90 hp and 4.3 AT 85 hp unless the Diesel fuel type is required: they are 15.09 and 15.98 kg/hp.

Four-cylinder FWD Coupe. 5 generation 2.2 AT, 2.5 AT, 2.8 AT, 3.3 AT. Do not buy the 90 hp 2.5 AT if the 110 hp 2.5 AT is available: same 2500 cc, same 4 Inline, same 1358 kg, same fuel 95; the 110 hp car has 4 gears vs 3. The 122 hp 2.2 AT at 1358 kg beats the 115 hp 2.2 AT on power (122 vs 115) at identical 176 Nm; the cost is 3 gears vs 4. The 115 hp 2.2 AT with Ventilated disc matches the 115 hp Disc car on every number except the front-brake label — same 1358 kg — so the Ventilated disc car is the 115 hp choice if the brake type is the differentiator. The 122 hp Ventilated disc car is the one to skip on weight: +61 kg for the same 122 hp and 3 gears.

Diesel. Only 5 generation 4.3 AT: 85 hp, 224 Nm, 4300 cc, 6 V-shaped, 3 gears, FWD, 1358 kg, tank 63 L. Valves, feed, compression, bore, 0–100, vmax, consumption: not measured. It is the unique fuel type, not the unique good idea on specific power.

RWD Coupe, no Turbo. 4 generation 5.0 AT 157 hp is the best naturally aspirated specific power in that generation (31.4 hp/L) with 325 Nm @ 1600. 5.7 AT is +5 hp and +28 Nm for 723 cc more. 4.9 AT matches the 5.0’s 325 Nm at 1800 rpm instead of 1600, with 15 hp less. 4.3 AT 122 hp is the small 8. 3 generation buyers get only 3.8 AT 112 hp or 5.7 AT 162 hp.

If 5 generation 160 hp is the brief. 3.3 AT (4 Inline, 1358 kg, vmax not measured) vs 3.1 AT (8 V-shaped, 1392 kg, 195 km/h). Same 160 hp and 251 Nm. The 3.3 wins mass; the 3.1 wins a speed figure and cylinder count.

Do not choose on wheels, CO2, or eco class. All not measured. Do not choose 1 generation or 2 generation: zero modifications in the data.

Short map. Measured modern sedan: 6 generation 3.1 AT 177 hp, or 162 hp if payload wins. Peak power/torque: 4 generation 3.8 AT 172 hp Turbo. Best kg/hp with a kerb figure: 5 generation 3.3 AT 160 hp. Unique Diesel: 5 generation 4.3 AT. Smallest gasoline engine: 5 generation 2.2 AT (2190 cc), 122 hp at 1358 kg if power, 115 hp 4-speed if gears. Every other name is a step between those poles, and the numbers above are the size of the step.