Borgward Isabella

Borgward Isabella: which generation changed what

Year overlap 1958 exists in the data: generation 1 stop is 1958-12-31 and generation 2 start is 1958-01-01. Identify a 1958 car by the generation row, not by calendar year alone.

1 generation (1954-01-01 to 1958-12-31), Cabrio, 2 versions. Both 1.5 MT, both 75 × 84.5 bore × stroke, 175 mm clearance, 1395 kg gross, independent spring front and rear. The split is compression and brakes: 6.8 and front Disc on the 59 hp car; 8.2 and front Drum on the 74 hp car. Rear brakes are Drum on both.

2 generation (1958-01-01 to 1961-12-31), Cabrio, 3 versions. Bore × stroke moves to 74 × 84.5. Clearance is 170 mm (−5 mm vs generation 1). Compression is 8.2 on all three. Front brakes are Disc, rear Drum. Peak power rpm is 5400 on all three (generation 1 used 4700 on 59 hp and 5200 on 74 hp). Kerb weight is higher: 1110–1130 kg vs 1060–1080 kg.

Year overlap 1958 exists in the data: generation 1 stop is 1958-12-31 and generation 2 start is 1958-01-01. Identify a 1958 car by the generation row, not by calendar year alone.

Engine specs compared (all named 1.5 MT)

Same displacement on every row: 74 − 59 = 15 hp between the two generation-1 cars; 74 − 54 = 20 hp between the strongest and weakest generation-2 cars. Torque span is 114 − 108 = 6 Nm. Power per litre (hp ÷ 1.493): 39.5 (59 hp), 49.6 (74 hp), 36.2 (54 hp). The 74 hp 1.5 MT is the only version that crosses 49 hp/l.

Performance: 0–100 and top speed (mpg not measured)

Fastest 0–100 is 17 s, shared by both 1.5 MT 74 hp cars. Slowest is generation-2 1.5 MT 54 hp at 25 s — 8 s slower than the 74 hp pair, 2 s slower than generation-2 59 hp (23 s), 4 s slower than generation-1 59 hp (21 s).

Highest top speed in the table is generation-1 1.5 MT 74 hp at 153 km/h. Generation-2 1.5 MT 74 hp matches the 17 s sprint but tops out at 137 km/h — 16 km/h less. Generation-2 1.5 MT 54 hp is the slowest at 123 km/h (30 km/h below generation-1 74 hp). Both 59 hp cars share 130 km/h; the later one is 2 s slower to 100.

Do not infer mpg: city, highway, mixed, and CO2 are not measured.

Dimensions, weight, tank (wheel size not measured)

Lightest: generation-1 1.5 MT 59 hp at 1060 kg. Heaviest kerb: both generation-2 54 hp and 59 hp at 1130 kg (+70 kg vs the lightest). Gross weight splits: 1395 kg on both generation-1 cars; 1435 kg on generation-2 74 hp (+40 kg); 1700 kg on generation-2 54 hp and 59 hp (+305 kg vs generation 1). Payload from the numbers: 1395 − 1060 = 335 kg (gen1 59 hp); 1395 − 1080 = 315 kg (gen1 74 hp); 1435 − 1110 = 325 kg (gen2 74 hp); 1700 − 1130 = 570 kg on the two heavier generation-2 cars.

Kerb kg per hp: 1060/59 ≈ 18.0; 1080/74 ≈ 14.6; 1110/74 ≈ 15.0; 1130/54 ≈ 20.9; 1130/59 ≈ 19.2. Best mass-to-power is generation-1 1.5 MT 74 hp. Worst is generation-2 1.5 MT 54 hp.

Tank is 46 l on all five. Clearance is 175 mm then 170 mm. Wheel sizes are not measured.

Which 1.5 MT to choose, by the numbers

Want the highest measured speed and the best kg/hp: generation-1 1.5 MT 74 hp (74 hp, 114 Nm, 17 s, 153 km/h, 1080 kg, 14.6 kg/hp). Cost in the table vs the 59 hp sibling: +20 kg kerb, compression 8.2 instead of 6.8, torque peak at 3000 instead of 2400, front Drum instead of front Disc. Same 1395 kg gross and 175 mm clearance.

Want 74 hp with generation-2 chassis (Disc front, 74 × 84.5, 170 mm): generation-2 1.5 MT 74 hp. Same 17 s and 114 Nm as the earlier 74 hp car, +30 kg kerb (1110 vs 1080), +40 kg gross (1435 vs 1395), top speed 137 not 153. Power rpm 5400 not 5200. This is the only generation-2 car that is not on the 1700 kg gross row.

Want lightest kerb and Disc front in generation 1: generation-1 1.5 MT 59 hp (1060 kg, 21 s, 130 km/h, 108 Nm @ 2400, CR 6.8). Versus the same-name 59 hp in generation 2: −70 kg, −2 s to 100, same 130 km/h, +5 mm clearance, lower compression, earlier power peak (4700 vs 5400).

Want generation-2 59 hp: generation-2 1.5 MT 59 hp (1130 kg, 1700 kg gross, 23 s, 130 km/h, 108 Nm @ 3000, CR 8.2, Disc front). Versus generation-2 54 hp: +5 hp, −2 s, +7 km/h, identical 1130 / 1700 / 170 / 46 / 108 Nm. The 5 hp is the whole gap between those two rows.

Avoid if you want the least time to 100 and the highest top speed: generation-2 1.5 MT 54 hp (54 hp, 25 s, 123 km/h, 20.9 kg/hp). It shares the heaviest gross (1700 kg) with generation-2 59 hp and is 20 hp and 16 km/h behind generation-2 74 hp, with +20 kg kerb versus that 74 hp car.

If the search is “engine” or “motor”: there is one 1493 cm³ Gasoline Inline-4 family, Carburetor, boost No. You are not choosing a different engine size; you are choosing 54 / 59 / 74 hp, compression 6.8 vs 8.2, bore 75 vs 74, and the generation’s brake and weight row.

Reliability / problems: not measured in this data. Do not treat missing mpg, wheels, or eco class as “the car has none” — they are not measured.

Short pick: generation-1 1.5 MT 74 hp for 153 km/h and 14.6 kg/hp; generation-2 1.5 MT 74 hp if you want the later Disc-front, 74 mm bore car and accept 137 km/h; generation-1 1.5 MT 59 hp if you want 1060 kg; skip generation-2 1.5 MT 54 hp unless the 570 kg payload figure (1700 − 1130) is the point of the purchase.