Mercedes W142

Mercedes W142: which version to choose (1937–1942 Cabrio)

The Mercedes W142 was sold as one generation (1937–1942) in a Cabrio body with two petrol versions: 3.2 MT and 3.4 MT. There is no later generation to “step up to,” no restyle split, and no automatic or all-wheel variant in this dataset. The buying question is therefore only this: 3.2 MT versus 3.4 MT, on the numbers that exist.

The Mercedes W142 was sold as one generation (1937–1942) in a Cabrio body with two petrol versions: 3.2 MT and 3.4 MT. There is no later generation to “step up to,” no restyle split, and no automatic or all-wheel variant in this dataset. The buying question is therefore only this: 3.2 MT versus 3.4 MT, on the numbers that exist.

Both cars share rear-wheel drive (RWD), a 4-speed Manual, a front-mounted longitudinal engine, Carburetor feed, No boost, 6 Inline cylinders with 2 valves per cylinder, dependent spring suspension at both ends, drum brakes at both ends, and a 72-litre tank. Kerb weight, gross weight, ground clearance, wheels, 0–100, fuel use, CO2, and eco class are not measured for either version, so this guide does not invent them.

Generations: what actually changed between the two cars

1 generation (1937–1942), Cabrio, 2 versions. Both 3.2 MT and 3.4 MT are listed from 1937-01-01 to 1942-12-31. There is no second generation and no restyling generation in the data. What changed is the engine, not the years, body, gearbox, drive, tank, suspension, or brakes.

That matters for a purchase: you are not choosing “an older W142” versus “a newer W142.” You are choosing two concurrent Cabrio specifications. If a listing is dated inside 1937–1942, generation does not separate the cars; 3.2 MT versus 3.4 MT does.

Specs and engine: side-by-side numbers

3.4 MT has 2 hp and 1 kW more than 3.2 MT (80 vs 78; 58 vs 57), both quoted at 4000 rpm. Peak torque is the same: 218 Nm at 1700 rpm on both. Displacement rises by 197 cc (3405 − 3208). Bore × stroke is 82.5 × 100 on 3.2 MT and 85 × 100 on 3.4 MT — stroke is unchanged; bore is 2.5 mm larger. Compression is 5.6 on 3.2 MT and 7.25 on 3.4 MT (1.65 higher on the larger engine).

Power per litre (from these figures): 3.2 MT is 78 / 3.208 ≈ 24.3 hp/L; 3.4 MT is 80 / 3.405 ≈ 23.5 hp/L. Torque per litre: 3.2 MT is 218 / 3.208 ≈ 68.0 Nm/L; 3.4 MT is 218 / 3.405 ≈ 64.0 Nm/L. The extra displacement on 3.4 MT does not raise specific output; it slightly lowers it while adding 2 hp.

If you want the denser engine on paper, that is 3.2 MT. If you want the higher peak horsepower and the higher compression ratio, that is 3.4 MT. Neither version has boost; neither is anything other than Gasoline, Carburetor, Inline 6.

Performance and mpg: what is measured and what is not

0–100: not measured for 3.2 MT; not measured for 3.4 MT. Do not treat one Cabrio as the “quicker” car on acceleration — the figure is absent on both.

Top speed: 3.2 MT 130; 3.4 MT 126. The smaller-displacement 3.2 MT is 4 units faster at the top of the scale in this dataset, despite 2 hp less. That is the only measured performance gap. It is the opposite of “bigger engine, higher top speed.”

Fuel consumption (mpg / city / highway / mixed): not measured for 3.2 MT; not measured for 3.4 MT. CO2: not measured. Eco class: not measured. A buyer cannot pick the “more economical W142” from these figures. Tank volume is identical (72), so range cannot be ranked either without consumption data.

Reliability / problems: this dataset has no failure rates, no service intervals, and no common-fault list. What can be said without leaving the numbers: both versions use the same layout family (6 Inline, 2 valves per cylinder, No boost, Carburetor, Manual 4, RWD, drum/drum, dependent spring/dependent spring). Compression is the mechanical difference that is actually quantified: 5.6 versus 7.25. That is a real spec gap; it is not a reliability ranking.

Dimensions, weight, and tank

Kerb weight: not measured (3.2 MT and 3.4 MT). Gross weight: not measured (both). Ground clearance: not measured (both). Wheel sizes: not measured (both). Tank: 72 on 3.2 MT; 72 on 3.4 MT.

Weight per horsepower cannot be calculated: mass is not measured. You cannot say which Cabrio is the lighter or “more athletic” car on weight. Dimensions that would usually separate generations are not in this file at all; with one generation, there is no generation-to-generation size jump to discuss.

What is shared and measured in the chassis description: Dependent, spring front; Dependent, spring rear; Drum front; Drum rear — identical wording on 3.2 MT and 3.4 MT. Drive is RWD on both. If a seller’s pitch is “better chassis on the 3.4,” these fields do not support it.

Which version to choose

There is one generation and two versions. Extra money, if any, is not in this dataset — so the comparison is only what the extra 197 cc, 2 hp, and 1.65 compression points buy, and what they do not.

Choose 3.2 MT if you want the higher listed top speed (130 vs 126), the higher specific output (about 24.3 hp/L vs 23.5 hp/L), and the higher torque density (about 68.0 Nm/L vs 64.0 Nm/L), with the same 218 Nm peak as the other car. You give up 2 hp and 1 kW, a 2.5 mm smaller bore, and the lower compression ratio (5.6 vs 7.25). Displacement is 3208 versus 3405. Gearbox, drive, tank, suspension, and brakes match 3.4 MT.

Choose 3.4 MT if the priority is the higher peak power in the table: 80 hp / 58 kW at 4000 rpm versus 78 / 57. You also get compression 7.25 instead of 5.6 and bore 85 instead of 82.5, stroke still 100. You do not get more torque (218 Nm at 1700 on both), you do not get a higher top speed (126, which is 4 below 3.2 MT), and you do not get a different gearbox, drive, tank, or brake type. Specific power and specific torque are both lower than on 3.2 MT.

Do not choose on these, because they are not measured on either car: 0–100, city/highway/mixed consumption, mpg, CO2, eco class, kerb weight, gross weight, ground clearance, wheels, and therefore power-to-weight. Generation choice is also not available: both versions sit in 1 generation, 1937–1942, Cabrio.

Arithmetic summary (allowed differences only): +2 hp, +1 kW, +197 cc, +2.5 mm bore, +1.65 compression, 0 Nm torque change, −4 top speed, 0 tank change, same Manual 4 and RWD. That is the whole measured trade on Mercedes W142 3.2 MT versus 3.4 MT.