Buick Rainer

Buick Rainer: which version to buy (2003–2007)

If you are choosing a Buick Rainer, you are not choosing between generations — there is 1 generation (2003-01-01 to 2007-12-31), one body (SUV 5-doors), and 8 gasoline automatics. The real decision is 4.2 AT versus 5.3 AT, 279 / 294 / 295 / 304 hp, and RWD versus AWD.

If you are choosing a Buick Rainer, you are not choosing between generations — there is 1 generation (2003-01-01 to 2007-12-31), one body (SUV 5-doors), and 8 gasoline automatics. The real decision is 4.2 AT versus 5.3 AT, 279 / 294 / 295 / 304 hp, and RWD versus AWD. Every 4.2 AT and every 5.3 AT in the data uses a 4-speed Automatic, 92 fuel, no boost, front longitudinal engine, 83 L tank, 200 mm ground clearance, independent spring front / dependent pneumatic rear, and disc brakes front and rear (labelled Disc in the data). Wheel sizes are not measured on all eight versions.

Buick Rainer specs: the eight versions side by side

There is no restyling generation to pick. Production start and stop are the same on all eight: 2003-01-01–2007-12-31.

Engine: 4.2 AT vs 5.3 AT (power per litre, torque, rpm)

4.2 AT is the 4157 cc 6, Inline, 4 valves per cylinder, compression 10.3, bore × stroke 93 × 102, multi-point injection. Two power levels:

• 4.2 AT 279 hp: 373 Nm at 3600 rpm.
• 4.2 AT 295 hp: +16 hp and +12 kW versus 279 hp; torque is only +2 Nm (375 vs 373), but peak torque is 1200 rpm later (4800 vs 3600).

Specific output: 279 / 4.157 ≈ 67.1 hp/L; 295 / 4.157 ≈ 71.0 hp/L. The 295 hp 4.2 AT is the densest engine in the catalogue.

5.3 AT is the 5327 cc 8, V-shaped, 2 valves per cylinder, compression 9.9, bore × stroke 96 × 92. Two power levels and a torque split:

• 5.3 AT 294 hp AWD: 441 Nm at 4000 rpm.
• 5.3 AT 294 hp RWD: 447 Nm at 4000 rpm (+6 Nm versus the 294 hp AWD).
• 5.3 AT 304 hp RWD and 5.3 AT 304 hp AWD: 304 hp / 224 kW at 5200 rpm, 447 Nm at 4000 rpm.

Specific output: 294 / 5.327 ≈ 55.2 hp/L; 304 / 5.327 ≈ 57.1 hp/L. The larger engine is less “busy” per litre than any 4.2 AT.

Torque gap versus the weakest six: 447 − 373 = +74 Nm on the 447 Nm 5.3 AT versions; 441 − 373 = +68 Nm on the 294 hp AWD. Versus the 295 hp 4.2 AT (375 Nm): +66 Nm or +72 Nm. Peak power on 5.3 AT arrives at 5200 rpm, 800 rpm earlier than on 4.2 AT (6000 rpm). Peak torque on 5.3 AT is at 4000 rpm — later than 279 hp 4.2 AT (3600) and earlier than 295 hp 4.2 AT (4800).

If you want peak hp/L, buy 4.2 AT 295 hp. If you want peak Nm, buy a 5.3 AT with 447 Nm (294 hp RWD, or either 304 hp). The 294 hp AWD 5.3 AT is the only eight-cylinder with 441 Nm instead of 447 Nm.

Performance: 0–100 and top speed (what extra hp actually buys)

Measured 0–100 km/h:

• 4.2 AT 279 hp RWD: 8.2 s, 175 km/h.
• 4.2 AT 279 hp AWD: 9.0 s, 175 km/h (+0.8 s for AWD).
• 4.2 AT 295 hp RWD: 8.2 s, 175 km/h (same 0–100 and top speed as 279 hp RWD despite +16 hp).
• 4.2 AT 295 hp AWD: 9.0 s, 175 km/h (same as 279 hp AWD).
• All four 5.3 AT versions: 7.6 s.

Top speed is not the same on the eights:

• 5.3 AT 294 hp AWD: 175 km/h (tied with every 4.2 AT).
• 5.3 AT 294 hp RWD: 180 km/h (fastest Rainer in the data, +5 km/h vs 175).
• 5.3 AT 304 hp RWD and AWD: 177 km/h (+2 vs 175, −3 km/h vs 294 hp RWD).

What the numbers say: AWD on 4.2 AT costs 0.8 s to 100 km/h and buys 0 km/h extra top speed. Stepping from 279 to 295 hp on 4.2 AT buys 0.0 s and 0 km/h in the measured pair. Stepping from any 4.2 AT RWD (8.2 s) to any 5.3 AT (7.6 s) buys 0.6 s. Stepping from 4.2 AT AWD (9.0 s) to 5.3 AT buys 1.4 s. The 304 hp 5.3 AT does not beat the 294 hp 5.3 AT to 100 km/h (both 7.6 s) and is 3 km/h slower on top speed than 294 hp RWD.

MPG / fuel consumption: only two versions were measured

City / highway / combined is not measured on six of eight versions. The only published figures are identical on both AWD sixes:

• 4.2 AT 279 hp AWD: 15.7 / 11.2 / 13.1 L/100 km.
• 4.2 AT 295 hp AWD: 15.7 / 11.2 / 13.1 L/100 km.

The extra 16 hp on AWD 4.2 AT does not change the published consumption. All four 5.3 AT versions and both RWD 4.2 AT versions: city not measured, highway not measured, mixed not measured. CO2 and eco class: not measured on all eight. Fuel grade is 92 on all eight. Tank is 83 L on all eight — you cannot buy range with a larger tank.

Do not infer that the eights are thirstier or the RWD sixes are leaner: those figures are not measured.

Dimensions, weight, payload: kg per horsepower

Wheel size: not measured on every version. Ground clearance: 200 mm on every version — AWD does not raise the Rainer in this dataset.

Kerb / gross / payload (gross − kerb) / kg per hp (kerb / hp):

AWD vs RWD on the same engine family: +85 kg kerb on 4.2 AT (2150 − 2065) and +85 kg on 5.3 AT (2170 − 2085). The six is 20 kg lighter than the matching-drive eight (2065 vs 2085 RWD; 2150 vs 2170 AWD).

Gross weight is the hidden split among 4.2 AT AWD twins: 279 hp AWD is 2608 kg GVW (payload 458 kg); 295 hp AWD is 2810 kg GVW (payload 660 kg). That is +202 kg gross and +202 kg payload for the same 2150 kg kerb. Among eights, AWD adds 91 kg GVW (2722 − 2631) and 6 kg payload (552 − 546).

Lightest Rainer: 4.2 AT RWD at 2065 kg (both 279 and 295 hp). Best kg/hp: 5.3 AT 304 hp RWD at 6.86 kg/hp. Worst kg/hp: 4.2 AT 279 hp AWD at 7.71 kg/hp. Heaviest kerb: both AWD 5.3 AT at 2170 kg. Highest payload: 4.2 AT 295 hp AWD at 660 kg.

RWD vs AWD: what the extra mass buys

On 4.2 AT, AWD is slower (9.0 vs 8.2 s), same 175 km/h, +85 kg, and is the only place consumption is measured (13.1 mixed). On 5.3 AT, AWD does not change 0–100 (7.6 s on all four). Top speed: AWD 294 hp is 175; AWD 304 hp is 177; RWD 294 hp is 180; RWD 304 hp is 177. So AWD never has the highest top speed. If you do not need AWD, RWD is lighter and, on 4.2 AT, quicker to 100.

Which Buick Rainer version to choose

Want the strongest specific output and a light six, rear-drive: 4.2 AT 295 hp RWD — 71.0 hp/L, 2065 kg, 7.00 kg/hp, 8.2 s, 175 km/h. Versus 279 hp RWD 4.2 AT you gain 16 hp and 2 Nm and lose nothing in 0–100 or top speed; consumption remains not measured on both.

Want AWD on the six and the highest payload in the range: 4.2 AT 295 hp AWD — 2150 kg kerb, 2810 kg gross, 660 kg payload, 9.0 s, 175 km/h, 15.7 / 11.2 / 13.1. Versus 279 hp AWD 4.2 AT you pay the same published fuel and the same 9.0 s, but you gain 202 kg of permitted gross mass.

Want AWD on the six and do not need the 2810 kg GVW: 4.2 AT 279 hp AWD matches 279 hp engine torque at 3600 rpm (earlier than the 295 hp six) with the same 13.1 mixed figure.

Want the quickest 0–100 and the highest top speed: 5.3 AT 294 hp RWD — 7.6 s, 180 km/h, 447 Nm, 2085 kg. The 304 hp RWD 5.3 AT is the same 7.6 s and same 2085 / 2631 kg, with +10 hp, same 447 Nm, but 177 km/h (−3). If top speed is the tie-breaker, 294 hp RWD wins; if kg/hp is the tie-breaker, 304 hp RWD wins (6.86 vs 7.09).

Want AWD and the eight-cylinder: choose between 5.3 AT 294 hp AWD (441 Nm, 175 km/h, 7.38 kg/hp) and 5.3 AT 304 hp AWD (447 Nm, 177 km/h, 7.14 kg/hp). Both: 7.6 s, 2170 / 2722 kg, consumption not measured. The 304 hp AWD is the better AWD eight on paper: +10 hp, +6 Nm, +2 km/h, −0.24 kg/hp, same weight.

Avoid expecting a “new generation” or a restyle split. One generation, eight versions, same years. Avoid expecting wheel specs, CO2, eco class, or mpg on the eights and RWD sixes — those are not measured.

Short buy list: daily RWD six → 4.2 AT 295 hp RWD. AWD six with load → 4.2 AT 295 hp AWD. Fastest recorded speed → 5.3 AT 294 hp RWD. Best mass-to-power → 5.3 AT 304 hp RWD. AWD V-shaped eight → 5.3 AT 304 hp AWD.