Delage D6

Delage D6: which version to choose

The Delage D6 ran as 1 generation from 1930 to 1940, all as Coupe, with 10 gasoline Manual RWD versions. There is no second generation to compare, so the buying question is only which engine among those ten. Names below are exactly as in the data; three share the label 2.7 MT and two share 2.0 MT, so they are split by horsepower.

The Delage D6 ran as 1 generation from 1930 to 1940, all as Coupe, with 10 gasoline Manual RWD versions. There is no second generation to compare, so the buying question is only which engine among those ten. Names below are exactly as in the data; three share the label 2.7 MT and two share 2.0 MT, so they are split by horsepower.

Specs: all 10 versions compared

Every version is Gasoline, 6 cylinders Inline, 2 valves per cylinder, boost No, Carburetor, Front, longitudinal, Manual 4, RWD, front Independent, leaf spring, rear Dependent, leaf spring, Drum brakes front and rear, fuel 76. Torque is not measured on all ten.

Engine: power per litre and what extra displacement buys

2.7 MT at 95 hp / 71 kW is the strongest D6: 17 hp more than 2.7 MT at 78 hp on the same 2729 cc (+22%), 30 hp more than 2.7 MT at 65 hp / 2678 cc, and 5 hp more than the largest engine, 3.6 MT at 90 hp / 3557 cc. Specific output: 95 / 2.729 ≈ 34.8 hp/L versus 78 / 2.729 ≈ 28.6 hp/L, 90 / 3.557 ≈ 25.3 hp/L, and 65 / 2.678 ≈ 24.3 hp/L. The extra 51 cc from 2678 to 2729 is not what explains 95 vs 65 hp; output on the 2729 cc pair is a tune difference at the same 3500 rpm.

The two 2.0 MT cars share 2011 cc. 2.0 MT 60 hp / 45 kW @ 4500 is 5 hp above 2.0 MT 55 hp / 41 kW @ 4000 (+9%). Specific output: 29.8 hp/L vs 27.3 hp/L. Both beat every engine above 2.3 L except the 78 hp and 95 hp 2.7 MT cars.

2.3 MT 56 hp / 2335 cc is almost the same power as 2.0 MT 55 hp but 324 cc larger: 24.0 hp/L. Versus 2.0 MT 60 hp it is 4 hp weaker and 324 cc bigger — more displacement, less power.

2.5 MT 67 hp / 2528 cc sits 11 hp above 2.3 MT and 2 hp above 2.7 MT 65 hp despite 150 cc less than that 2678 cc engine: 26.5 hp/L vs 24.3 hp/L.

3.1 MT 72 hp / 53 kW @ 3600, 3045 cc, and 3.2 MT 72 hp / 54 kW @ 3500, 3227 cc, match on horsepower. The 3.2 MT is 182 cc larger and 1 kW higher; specific output 23.7 hp/L vs 22.3 hp/L. 3.1 MT is the only version with bore × stroke in the data: 77 × 109.

3.6 MT 90 hp is 18 hp above either 72 hp six and 828 cc above 3.1 MT, but 5 hp below 2.7 MT 95 hp with 828 cc more than 2729. Extra capacity here does not buy the catalogue’s peak power.

Spread across the range: 55–95 hp (40 hp), 2011–3557 cc (1546 cc). Peak rpm is 4500 only on 2.0 MT 60 hp; 4000 on 2.0 MT 55 hp and 2.7 MT 65 hp; 3600 on 3.1 MT; 3500 on the other six.

Performance, mpg, and dimensions: what is measured

0–100, city / highway / combined consumption, CO2, eco class: not measured on all ten. Do not rank D6 versions on acceleration or mpg; those figures are absent.

Top speed is measured only on 3.1 MT: 130 (units as in the data). The other nine: not measured. A 130 figure cannot be used to say 3.1 MT is faster than 2.7 MT 95 hp.

Kerb weight is measured only on 3.1 MT: 1400. Gross weight, ground clearance, tank, wheels: not measured on all ten. Power-to-weight is only computable for 3.1 MT: 1400 / 72 ≈ 19.4 kg/hp. You cannot compare kg/hp across versions.

Which version to choose

If the criterion is peak power: 2.7 MT 95 hp / 71 kW. It is the top of the table, the highest hp/L (34.8), and it beats 3.6 MT 90 hp without the largest displacement.

If the criterion is the same 2729 cc with less output: 2.7 MT 78 hp / 58 kW. Same capacity as the 95 hp car, 17 hp less, still 11 hp above 2.5 MT and 13 hp above 2.7 MT 65 hp.

If the criterion is the third 2.7-litre label: 2.7 MT 65 hp uses 2678 cc, not 2729. It is 13 hp below 2.7 MT 78 hp and 30 hp below 2.7 MT 95 hp. Treat it as a different engine, not a weaker twin of the 2729 cc pair.

If the criterion is smallest engine: the two 2.0 MT versions (2011 cc). Choose 2.0 MT 60 hp over 2.0 MT 55 hp for 5 hp and a higher peak rpm (4500 vs 4000). 2.0 MT 60 hp also out-powers 2.3 MT 56 hp.

If the criterion is mid-size without the 2.7 MT cluster: 2.5 MT 67 hp is 11 hp above 2.3 MT and close to 2.7 MT 65 hp with 150 cc less.

If the criterion is a measured top speed and kerb weight: only 3.1 MT (72 hp, 3045 cc, 130, 1400). 3.2 MT matches 72 hp with 3227 cc and not measured speed and weight — same horsepower, no extra measured figures.

If the criterion is largest displacement: 3.6 MT 90 hp / 3557 cc. It is 5 hp short of 2.7 MT 95 hp and 25.3 hp/L vs 34.8. Size and peak power do not line up on this model.

Do not choose on gearbox, drive, body, or generation: all ten are Coupe, Manual 4, RWD, same suspension and drums, same 1930–1940 generation. The arithmetic difference is engine output and capacity, plus the two measured fields that exist only on 3.1 MT.