Mercedes W128

Mercedes W128: which 2.2 MT to buy — 120 hp or 115 hp

The Mercedes W128 exists as one generation (1958–1960), one body type (Cabrio), and two versions that share the same catalogue name: 2.2 MT. The buying question is not “which generation” — there is only one — and not “which body.” It is which 2.2 MT you want: the 120 hp car or the 115 hp car.

The Mercedes W128 exists as one generation (1958–1960), one body type (Cabrio), and two versions that share the same catalogue name: 2.2 MT. The buying question is not “which generation” — there is only one — and not “which body.” It is which 2.2 MT you want: the 120 hp car or the 115 hp car. Both use a 2195 cc Gasoline Inline 6, No boost, Front, longitudinal placement, Central injection (single-point or single- point), a 4-speed Manual, and RWD. Both reach 100 km/h in 15 s. The 120 hp 2.2 MT is stronger on paper (+5 hp, +3 Nm, +5 km/h top speed) and carries 8 litres more tank volume (70 vs 62). Kerb weight, gross weight, ground clearance, wheels, fuel use, and CO2 are not measured for either car, so weight-per-horsepower and mpg cannot be scored.

Specs that actually differ between the two 2.2 MT versions

Both versions are labelled 2.2 MT. Distinguish them by power, as required when names collide.

Compression ratio is 8.7 on both. Valves per cylinder: 2. Bore × stroke is 80 × 72.8 on the 120 hp 2.2 MT and not measured on the 115 hp 2.2 MT. Front and rear suspension: Independent, spring on both. Front and rear brakes: Drum on both.

Engine: same 2195 cc, 5 hp and 3 Nm apart

Power per litre (arithmetic on the given figures):

• 2.2 MT 120 hp: 120 ÷ 2.195 ≈ 54.7 hp/L (88 kW ÷ 2.195 ≈ 40.1 kW/L)
• 2.2 MT 115 hp: 115 ÷ 2.195 ≈ 52.4 hp/L (85 kW ÷ 2.195 ≈ 38.7 kW/L)

The extra 5 hp is about 4.3% more power (5 ÷ 115) and about 2.3 hp/L more specific output. Peak power arrives at the same 4800 rpm on both, so the 120 hp car is not a higher-revving tune on this data — it is a higher peak at the same rpm.

Torque:

• 120 hp 2.2 MT: 189 Nm at 3900 rpm
• 115 hp 2.2 MT: 186 Nm at 3800 rpm

The gap is 3 Nm (1.6% more on the 120 hp car). Peak torque is 100 rpm later on the stronger version. That is a small timing shift, not a different displacement: both are 2195 cc, 6 cylinders, Inline, No boost, Front, longitudinal, Central injection (single-point or single- point).

kW gap: 88 − 85 = 3 kW. Same story as the horsepower gap.

If you are choosing on engine output alone, the 2.2 MT with 120 hp / 88 kW / 189 Nm is the higher-output of the two. The 2.2 MT with 115 hp / 85 kW / 186 Nm is the milder of the same 2195 cc Gasoline layout.

Performance: 0–100 is a tie; top speed is not

0–100 km/h is 15 s for both 2.2 MT versions. The extra 5 hp and 3 Nm do not show up as a shorter sprint in this dataset. Do not invent a quicker 120 hp car to 100 km/h: the measured figure is the same 15 s.

Top speed does split:

• 120 hp 2.2 MT: 165
• 115 hp 2.2 MT: 160

Difference: 5 (about 3.1% higher on the 120 hp car: 5 ÷ 160). If the buying criterion is the highest recorded speed, take the 120 hp 2.2 MT. If you only care about the 0–100 number, the two cars are equal.

Fuel consumption (city, highway, mixed) is not measured for either version. MPG, L/100 km, and range from a consumption figure cannot be calculated. CO2 and eco class are not measured. Economy cannot be a tie-breaker because there is no economy figure.

Tank volume can be compared and does affect how far a full fill can theoretically go if consumption were known — it is not:

• 120 hp 2.2 MT: 70
• 115 hp 2.2 MT: 62

Difference: 8 litres (12.9% more on the 120 hp car: 8 ÷ 62). Relative tank size favors the 120 hp 2.2 MT. Absolute range in kilometres is not measured.

Dimensions, weight, mpg: what is not measured

Kerb weight: not measured (both). Gross weight: not measured (both). Ground clearance: not measured (both). Wheel sizes: not measured (both).

Weight per horsepower cannot be computed. You cannot say which 2.2 MT is “lighter per hp.” You cannot score payload. You cannot compare ride height.

What is measured on the chassis side is the same for both: Independent, spring front, Independent, spring rear, Drum front, Drum rear. There is no brake or suspension upgrade between the two versions in this data. Chassis spec is not a reason to pick one 2.2 MT over the other.

Generations: there is only one, so generation is not a choice

1 generation, 1958-01-01 to 1960-12-31, body Cabrio, 2 versions. No second generation, no restyling generation in the data. You are not choosing between an early and a late generation of W128. You are choosing between two concurrent 2.2 MT cars inside the same 1958–1960 Cabrio generation. Both versions share the same start and stop dates (1958-01-01–1960-12-31). Production window does not separate them.

What did not change between the two versions (same generation, same years): displacement 2195, fuel Gasoline, cylinders 6, layout Inline, valves per cylinder 2, boost No, engine position Front, longitudinal, feed Central injection (single-point or single- point), compression 8.7, gearbox Manual, gears 4, drive RWD, 0–100 15 s, suspension type, brake type.

What did change: power (120 vs 115 hp; 88 vs 85 kW), torque (189 vs 186 Nm), torque rpm (3900 vs 3800), top speed (165 vs 160), tank (70 vs 62), and bore × stroke (80 × 72.8 vs not measured).

Reliability and problems

No reliability scores, failure rates, or problem lists are in the data. Do not treat silence as “no problems.” Reliability is not measured. Both cars share the same recorded mechanical pattern: Gasoline Inline 6, No boost, Manual 4, RWD, Drum brakes, Independent, spring suspension. Any reliability argument that is not in those fields is outside this catalogue.

Which version to choose

Choose the 2.2 MT (120 hp) if you want the higher output and the larger tank of this pair. You get 120 hp vs 115 hp (+5 hp, +4.3%), 88 kW vs 85 kW (+3 kW), 189 Nm vs 186 Nm (+3 Nm), 165 vs 160 top speed (+5), and a 70 vs 62 tank (+8). Specific output is about 54.7 hp/L vs 52.4 hp/L. Bore × stroke is recorded as 80 × 72.8 on this version. You do not get a faster 0–100: it remains 15 s.

Choose the 2.2 MT (115 hp) if you want the milder of the two 2195 cc Gasoline Inline 6 cars and accept 115 hp, 85 kW, 186 Nm at 3800 rpm, 160 top speed, and a 62 tank. 0–100 is still 15 s — identical to the 120 hp car. Peak torque is 100 rpm earlier (3800 vs 3900). Bore × stroke is not measured on this version.

Do not choose on generation, body, gearbox, or drive. There is one generation, one Cabrio, one Manual 4, one RWD. Those fields do not split the market.

Do not choose on mpg, weight, or clearance. City, highway, and mixed consumption are not measured. Kerb weight, gross weight, ground clearance, and wheels are not measured. “What the extra money buys” cannot be priced: prices are not in the data. What the extra output buys, in numbers we have, is 5 hp, 3 kW, 3 Nm, 5 more top speed, and 8 more tank litres — not a shorter 0–100 time.

Short rule: if the catalogue name is 2.2 MT, read the horsepower. 120 hp is the stronger, faster-at-the-top, larger-tank car. 115 hp is the milder twin with the same 15 s to 100 and the same 2195 cc Gasoline Inline 6, No boost, Manual 4, RWD layout.