Mercedes W120

Which version to buy: 1.8 MT 39 hp vs 1.8 MT 59 hp vs 1.9 MT

If the question is “which W120 to buy,” the numbers rank the three versions in a straight line. 1.9 MT is the fastest and strongest: 69 hp (51 kW) at 4500 rpm, 145 Nm at 2500 rpm, 0–100 in 21 s, 135 km/h, 1897 cm³ Gasoline, Carburetor, compression 7, 1165 kg.

If the question is “which W120 to buy,” the numbers rank the three versions in a straight line. 1.9 MT is the fastest and strongest: 69 hp (51 kW) at 4500 rpm, 145 Nm at 2500 rpm, 0–100 in 21 s, 135 km/h, 1897 cm³ Gasoline, Carburetor, compression 7, 1165 kg. 1.8 MT at 59 hp is the lightest and the middle of the pack: 59 hp (43 kW) at 4000 rpm, 111 Nm at 1800 rpm, 0–100 in 31 s, 126 km/h, 1767 cm³ Gasoline, Carburetor, compression 6.7, 1070 kg. 1.8 MT at 39 hp is the slowest and heaviest: 39 hp (29 kW) at 3200 rpm, 101 Nm at 2000 rpm, 0–100 in 39 s, 110 km/h, 1767 cm³ Diesel, no boost, compression 19, 1200 kg.

The two 1.8 MT names are identical in the catalogue. They are not the same car. Separate them by power: 39 hp Diesel versus 59 hp Gasoline. Displacement, cylinder count, cylinder layout, valves per cylinder, boost, gearbox, drive, tank, suspension, and brakes match; fuel type, output, weight, and performance do not.

Generations: one generation, three versions, nothing restyled as a later car

There is 1 generation (1953-01-01–1962-12-31), body Sedan, 3 versions. No later generation exists in this data to buy into, so “which generation” collapses to “which of the three 1.8 MT / 1.9 MT cars inside that window.” All three versions carry the same start and stop dates. Buying a later year does not, on these figures, buy a different gearbox, drive, tank, or brake type.

Engines and specs: what each version actually is

1.8 MT 39 hp: 29 kW at 3200 rpm, 101 Nm at 2000 rpm, 4 cylinders, Inline, 2 valves per cylinder, No boost, compression 19, bore × stroke 75 × 100, fuel system not measured, engine position not measured.

1.8 MT 59 hp: 43 kW at 4000 rpm, 111 Nm at 1800 rpm, 4 cylinders, Inline, 2 valves per cylinder, No boost, Carburetor, compression 6.7, bore × stroke 75 × 100.

1.9 MT: 51 kW at 4500 rpm, 145 Nm at 2500 rpm, 4 cylinders, Inline, 2 valves per cylinder, No boost, Carburetor, compression 7, bore × stroke 85 × 83.58.

The Gasoline pair uses Carburetor; the Diesel 1.8 MT 39 hp has a fuel system that is not measured. None of the three has boost. All are 4-speed Manual and RWD, so the gearbox and drive columns do not separate the field.

Specs that actually change the ranking: power per litre and kg per hp

Power per litre (hp ÷ displacement in litres):

• 1.8 MT 39 hp Diesel: 39 ÷ 1.767 ≈ 22.1 hp/L
• 1.8 MT 59 hp Gasoline: 59 ÷ 1.767 ≈ 33.4 hp/L
• 1.9 MT: 69 ÷ 1.897 ≈ 36.4 hp/L

Kerb weight per horsepower:

• 1.8 MT 39 hp: 1200 ÷ 39 ≈ 30.8 kg/hp
• 1.8 MT 59 hp: 1070 ÷ 59 ≈ 18.1 kg/hp
• 1.9 MT: 1165 ÷ 69 ≈ 16.9 kg/hp

1.9 MT leads both ratios. 1.8 MT 59 hp is close on kg/hp because it is the lightest car in the set (1070 kg). 1.8 MT 39 hp is last on both: lowest specific output and the highest mass per horsepower, 12.7 kg/hp heavier than the 59 hp 1.8 MT and 13.9 kg/hp heavier than 1.9 MT.

Torque per litre:

• 1.8 MT 39 hp: 101 ÷ 1.767 ≈ 57.2 Nm/L
• 1.8 MT 59 hp: 111 ÷ 1.767 ≈ 62.8 Nm/L
• 1.9 MT: 145 ÷ 1.897 ≈ 76.4 Nm/L

1.9 MT also leads torque density. Peak torque arrives at 2500 rpm on 1.9 MT, versus 2000 rpm on Diesel 1.8 MT and 1800 rpm on Gasoline 1.8 MT. The 59 hp 1.8 MT makes its 111 Nm earliest in the rev range; the Diesel makes 101 Nm 200 rpm later and 10 Nm lower.

Performance and economy: 0–100, top speed, mpg

0–100 and top speed are measured. Fuel consumption (city, highway, mixed) is not measured on any version, so mpg cannot pick a winner.

Arithmetic on the measured figures:

• Gasoline 1.8 MT 59 hp reaches 100 km/h 8 s sooner than Diesel 1.8 MT 39 hp (31 vs 39) and is 16 km/h faster at the top (126 vs 110).
• 1.9 MT reaches 100 km/h 10 s sooner than Gasoline 1.8 MT 59 hp (21 vs 31) and 18 s sooner than Diesel 1.8 MT 39 hp (21 vs 39).
• 1.9 MT top speed is 9 km/h above Gasoline 1.8 MT 59 hp (135 vs 126) and 25 km/h above Diesel 1.8 MT 39 hp (135 vs 110).

The step from Diesel 1.8 MT to Gasoline 1.8 MT is +20 hp (+51% vs 39 hp) and +10 Nm. The step from Gasoline 1.8 MT to 1.9 MT is +10 hp (+17% vs 59 hp) and +34 Nm. The extra 130 cm³ (1897 − 1767) on 1.9 MT is where most of the torque jump sits. If the buying question is acceleration, 1.9 MT is the only version under 22 s to 100 km/h. If the question is “good enough versus the Diesel,” Gasoline 1.8 MT 59 hp already cuts 8 s off 0–100 and adds 16 km/h of top speed without leaving the 1767 cm³ 1.8 MT name.

CO2 is not measured. Eco class is not measured.

Dimensions and weight: kerb, tank, clearance, wheels

Gross weight, ground clearance, and wheel sizes are not measured on any version. The tank is 56 L on all three, so range cannot be compared without consumption figures, which are also not measured.

Kerb weight is the only mass figure that moves:

• 1.8 MT 59 hp Gasoline: 1070 kg (lightest)
• 1.9 MT: 1165 kg (+95 kg vs 59 hp 1.8 MT, −35 kg vs Diesel 1.8 MT)
• 1.8 MT 39 hp Diesel: 1200 kg (+130 kg vs 59 hp 1.8 MT, +35 kg vs 1.9 MT)

1.9 MT is 95 kg heavier than the 59 hp 1.8 MT and still 10 s quicker to 100 km/h. The extra 10 hp and 34 Nm more than cover that 95 kg. Diesel 1.8 MT is both the heaviest and the least powerful, which is why its 30.8 kg/hp sits so far from the other two.

Independent spring front, independent spring rear, drum front, drum rear: identical, so chassis hardware in this dataset does not change the shopping list.

Reliability and problems: what this dataset can and cannot say

This catalogue block does not record failure rates, rust, parts, or known faults. Reliability and problems cannot be ranked from these numbers. What can be stated without leaving the data:

• All three versions are 4-cylinder Inline, 2 valves per cylinder, No boost, 4-speed Manual, RWD, drum/drum, independent spring/independent spring, 56 L tank.
• The Diesel 1.8 MT 39 hp is the only Diesel, the only version with compression 19 (versus 6.7 and 7 on the Gasoline pair), and the only one whose fuel system is not measured rather than Carburetor.
• The two Gasoline versions share Carburetor; they differ by 130 cm³, 10 hp, 34 Nm, 95 kg, 10 s on 0–100, and 9 km/h of top speed.
• Peak power rpm: 3200 (Diesel 1.8 MT) vs 4000 (Gasoline 1.8 MT) vs 4500 (1.9 MT). The Diesel is rated lowest in the rev range; 1.9 MT highest.

Do not treat “Diesel” as an economy argument here: mpg is not measured.

What the extra output buys, version by version

Buy 1.8 MT 39 hp (Diesel) if the requirement is Diesel and 1767 cm³, and 39 hp / 101 Nm / 110 km/h / 39 s to 100 km/h is acceptable. Versus Gasoline 1.8 MT 59 hp you give up 20 hp, 10 Nm, 16 km/h of top speed, and 8 s of 0–100, and you carry 130 kg more kerb weight. Versus 1.9 MT you give up 30 hp, 44 Nm, 25 km/h, and 18 s to 100 km/h. Specific output is about 22.1 hp/L versus 33.4 and 36.4. This is the low-output, high-mass end of the W120 set.

Buy 1.8 MT 59 hp (Gasoline) if the requirement is the lightest W120 in this data (1070 kg) at the 1767 cm³ 1.8 MT name, with Carburetor, 59 hp, 111 Nm, 126 km/h, 31 s to 100 km/h. Versus the Diesel 1.8 MT you gain 20 hp and lose 130 kg, which is why kg/hp drops from 30.8 to 18.1. Versus 1.9 MT you give up 10 hp, 34 Nm, 9 km/h, and 10 s to 100 km/h, but you are 95 kg lighter. Peak torque at 1800 rpm is the lowest rpm of the three. This is the middle performance choice and the mass minimum.

Buy 1.9 MT if the requirement is the highest figures in the generation: 69 hp, 145 Nm, 1897 cm³, 135 km/h, 21 s to 100 km/h, 36.4 hp/L, 16.9 kg/hp. Versus Gasoline 1.8 MT 59 hp the extra 130 cm³ buys +10 hp and +34 Nm; 0–100 improves by 10 s even with +95 kg. Versus Diesel 1.8 MT 39 hp it buys +30 hp, +44 Nm, −35 kg, −18 s to 100 km/h, and +25 km/h top speed. Bore × stroke changes from 75 × 100 on both 1.8 MT versions to 85 × 83.58 on 1.9 MT. Compression is 7 versus 6.7 on the 59 hp 1.8 MT. If the buying rule is “maximum measured speed and acceleration in this Sedan,” 1.9 MT is the version the numbers select.

There is no Automatic, no other drive, and no second generation in the data, so those filters do not apply. Prices are not in this dataset. Fuel use is not measured, so “which is cheaper to run” is not answered here. On the figures that are measured, the order is 1.9 MT, then 1.8 MT 59 hp Gasoline, then 1.8 MT 39 hp Diesel.