Chevrolet Lumina APV

Chevrolet Lumina APV versions: 3.1 AT vs 3.8 AT

There is no second generation to wait for. The catalogue lists one generation, two modifications, same body, same years (1989-01-01 to 1996-12-31). Year searches (1990, 1991, 1992, 1993, 1994, 1995, 1996) do not split the data: both 3.1 AT and 3.8 AT sit on that full span. The choice is the engine and gearbox pairing, not a facelift generation.

There is no second generation to wait for. The catalogue lists one generation, two modifications, same body, same years (1989-01-01 to 1996-12-31). Year searches (1990, 1991, 1992, 1993, 1994, 1995, 1996) do not split the data: both 3.1 AT and 3.8 AT sit on that full span. The choice is the engine and gearbox pairing, not a facelift generation.

Engine: what the extra 656 cc buys

3.1 AT displaces 3135 cc and makes 122 hp (90 kW) at 4200 rpm and 237 Nm at 2200 rpm. 3.8 AT displaces 3791 cc and makes 175 hp (129 kW) at 4700 rpm and 305 Nm at 3200 rpm.

Displacement gap: 3791 − 3135 = 656 cc (about 21% more on 3.8 AT). Power gap: 175 − 122 = 53 hp (about 43% more). Torque gap: 305 − 237 = 68 Nm (about 29% more). Kilowatt gap: 129 − 90 = 39 kW.

Specific output from those figures: 3.1 AT is 122 hp / 3.135 L ≈ 38.9 hp per litre. 3.8 AT is 175 hp / 3.791 L ≈ 46.2 hp per litre. The larger engine is not only bigger; it extracts more power per litre.

Compression: 3.1 AT 8.5, 3.8 AT 9. Both run fuel 92. Bore × stroke: 3.1 AT 89 × 84, 3.8 AT 96.5 × 86.4. Valves per cylinder: 2 on both. Boost: No on both. Cylinder count and layout: 6, V-shaped, on both. Engine position: not measured on both.

Fuel system is the other engine difference that is not a displacement number. 3.1 AT uses Central injection (single-point or single- point). 3.8 AT uses Distributed injection (multi-point). Same fuel grade, same cylinder layout, different injection type.

Peak torque rpm also differs: 2200 on 3.1 AT, 3200 on 3.8 AT. The smaller engine’s 237 Nm arrives 1000 rpm earlier. The larger engine’s 305 Nm arrives later but is 68 Nm higher. For low-speed van work, the 3.1 AT torque peak is the earlier number; for absolute torque, 3.8 AT is 305 vs 237.

Gearbox: 3-speed Automatic vs 4-speed Automatic

Both versions are Automatic and FWD. 3.1 AT has 3 gears. 3.8 AT has 4 gears. That is one extra ratio on the higher-output pairing, not a different drive layout.

If the catalogue name is read as a package: 3.1 AT is 122 hp + 3-speed Automatic + FWD. 3.8 AT is 175 hp + 4-speed Automatic + FWD. You do not get a 3-speed 3.8 AT or a 4-speed 3.1 AT in this dataset.

Weight per horsepower and dimensions

Kerb weight: 3.1 AT 1614 kg, 3.8 AT 1685 kg. Difference: 71 kg (about 4.4% heavier on 3.8 AT). Gross weight: not measured on both. Ground clearance: 175 mm on both. Tank: 77 L on both. Wheel sizes: not measured on both.

Weight per horsepower from kerb mass and peak hp: 3.1 AT 1614 / 122 ≈ 13.2 kg per hp. 3.8 AT 1685 / 175 ≈ 9.6 kg per hp. The extra 71 kg does not cancel the extra 53 hp; 3.8 AT carries fewer kilograms for each horsepower.

Chassis labels that do not split the choice: Independent, spring front and Independent, spring rear on both. Front brakes Ventilated disc, rear Drum, on both. Clearance and tank are identical, so neither version is the “taller” or “longer-range tank” option on these numbers.

Performance and mpg: measured vs not measured

3.1 AT: 0–100 in 13 s, top speed 160. City, highway, and combined fuel use: not measured. CO2: not measured. Eco class: not measured.

3.8 AT: 0–100 not measured, top speed not measured. City, highway, and combined fuel use: not measured. CO2: not measured. Eco class: not measured.

You cannot pick 3.8 AT because it is “faster to 100” in this catalogue: that figure is not measured. You can pick 3.1 AT if a measured 13 s to 100 and a measured 160 top speed are required. You cannot pick either version on mpg: city, highway, and mixed consumption are not measured for 3.1 AT and not measured for 3.8 AT. A missing mpg cell is not a claim that the van uses no fuel.

Which Chevrolet Lumina APV version to choose

Choose 3.1 AT when the measured acceleration and top-speed cells matter, when earlier peak torque (237 Nm at 2200 rpm) matters more than peak torque size, and when lower kerb weight (1614 kg vs 1685 kg) matters. You accept 122 hp, 3135 cc, Central injection (single-point or single- point), compression 8.5, 3-speed Automatic, and about 13.2 kg per hp.

Choose 3.8 AT when 175 hp, 305 Nm, 3791 cc, Distributed injection (multi-point), compression 9, and 4-speed Automatic matter more than the missing 0–100 and top-speed cells. You accept 71 kg extra kerb weight and a later torque peak (3200 rpm). You get about 46.2 hp per litre vs about 38.9, and about 9.6 kg per hp vs about 13.2.

Do not choose by generation. There is 1 generation, Minivan, two versions. Restyling is not listed as a separate generation. Do not choose by model year in the data: both 3.1 AT and 3.8 AT share 1989–1996. Do not choose by drive, tank, clearance, suspension, or brakes: FWD, 77 L, 175 mm, Independent, spring, Ventilated disc / Drum — same on both. Do not choose by mpg: not measured on both.

Arithmetic summary of the extra displacement: +656 cc, +53 hp, +39 kW, +68 Nm, +1 Automatic gear, +71 kg, +0.5 compression points, injection type change from Central injection (single-point or single- point) to Distributed injection (multi-point). Fuel stays 92. Boost stays No. Cylinders stay 6, V-shaped, 2 valves per cylinder.

If the van must have a published 0–100 and a published 160 top speed, the only version that supplies those cells is 3.1 AT. If the van must have the higher hp, higher Nm, higher hp per litre, lower kg per hp, and the 4-speed Automatic, the only version that supplies those cells is 3.8 AT. Those two sentences stay true if this paragraph is copied without the rest of the article.