Daimler DS420

Daimler DS420: which version to buy — 4.2 AT 164 hp vs 4.2 AT 178 hp

Between the two Daimler DS420 versions both named 4.2 AT, the 178 hp car is the stronger buy if the decision is power per litre and kilograms per horsepower. The 164 hp 4.2 AT is the stronger buy if the decision is measured top speed, measured fuel use, and a published gross weight. Both are 1 generation Limousine cars, 1968-01-01 to 1992-12-31.

Between the two Daimler DS420 versions both named 4.2 AT, the 178 hp car is the stronger buy if the decision is power per litre and kilograms per horsepower. The 164 hp 4.2 AT is the stronger buy if the decision is measured top speed, measured fuel use, and a published gross weight. Both are 1 generation Limousine cars, 1968-01-01 to 1992-12-31. There is no second generation in the data, so the choice is not “which generation” — it is which of the two 4.2 AT calibrations.

Overview: one generation, two 4.2 AT versions

The Daimler DS420 exists as 1 generation. Production start is 1968-01-01 and production stop is 1992-12-31. Body type is Limousine. Modification count is 2. Both versions keep the same catalogue name 4.2 AT; they are told apart by output: 164 hp and 178 hp. Displacement is 4235 cm³ on both. Fuel type is Gasoline on both. Gearbox is Automatic, 3 speeds, on both. Drive is RWD on both. Boost is No on both. Cylinder count is 6, layout is Inline, valves per cylinder is 2 on both. Fuel grade is 95 on both. Tank is 91 L on both. Ground clearance is 180 mm on both. Front brakes are Ventilated disc; rear brakes are Disc. Front and rear suspension are Independent, spring.

What changes is the feeding system, compression, peak power, peak torque, kerb weight, and which performance and economy figures were measured.

Generations: what 1 generation actually offers

1 generation (1968-01-01–1992-12-31), Limousine, 2 versions. There is no restyling listed as a separate generation. Both 4.2 AT lines share the same start and stop dates, so a buyer cannot pick an earlier generation or a later one — only the 164 hp 4.2 AT or the 178 hp 4.2 AT.

What 1 generation does not change between versions: 4235 cm³, Gasoline, 6 Inline, 2 valves per cylinder, No boost, Automatic 3, RWD, 91 L tank, 180 mm clearance, Independent spring suspension front and rear, Ventilated disc front / Disc rear, bore and stroke 92.07 × 106.

What 1 generation does change between versions: carburetor versus central injection, compression 7.5 versus 8.1, 164 hp versus 178 hp, 301 Nm versus 297 Nm, kerb 2135 kg versus 2160 kg, and a full set of measured speed and consumption figures on the 164 hp car that are not measured on the 178 hp car.

Engines and specs

4.2 AT 164 hp: feeding system Carburetor, compression 7.5, bore and stroke 92.07 × 106, fuel 95.

4.2 AT 178 hp: feeding system Central injection (single-point or single- point), compression 8.1, bore and stroke 92.07 × 106, fuel 95.

Power arithmetic on the same 4235 cm³: 164 ÷ 4.235 = 38.7 hp per litre on the 164 hp 4.2 AT; 178 ÷ 4.235 = 42.0 hp per litre on the 178 hp 4.2 AT. The injection car extracts 3.3 hp more from each litre (+8.5% peak power: 178 − 164 = 14 hp; 131 − 121 = 10 kW). Peak power rpm moves from 4500 to 4750 (+250 rpm).

Torque arithmetic goes the other way. The 164 hp 4.2 AT makes 301 Nm at 2500 rpm; the 178 hp 4.2 AT makes 297 Nm at the same 2500 rpm — 4 Nm less (−1.3%). Compression rises from 7.5 to 8.1 (+0.6). The extra 14 hp is not extra mid-range twist; it is a higher, later power peak on a 0.6-point higher compression ratio and a different feeding system.

Performance and economy (mpg / consumption)

0–100 km/h: not measured on the 164 hp 4.2 AT. Not measured on the 178 hp 4.2 AT. A buyer cannot rank sprint from these data.

Top speed: 177 km/h on the 164 hp 4.2 AT. Not measured on the 178 hp 4.2 AT. The only published maximum is 177 km/h, and it belongs to the carburetor car.

Fuel consumption, 164 hp 4.2 AT: city 24.1 L/100 km, highway 14.8 L/100 km, mixed 19.2 L/100 km. City is 9.3 L/100 km above highway (24.1 − 14.8). Mixed sits 4.4 L/100 km above highway and 4.9 L/100 km below city.

Fuel consumption, 178 hp 4.2 AT: city not measured, highway not measured, mixed not measured. The extra 14 hp does not come with a measured economy figure, so it cannot be claimed as thirstier or more efficient from these data.

CO2: not measured on both. Eco class: not measured on both.

Tank 91 L with mixed 19.2 L/100 km on the 164 hp 4.2 AT gives a mixed-range figure of 91 ÷ 19.2 × 100 = 474 km. City range on the same tank is 91 ÷ 24.1 × 100 = 378 km. Highway range is 91 ÷ 14.8 × 100 = 615 km. Those three distances apply only to the 164 hp 4.2 AT. The 178 hp 4.2 AT has the same 91 L tank and no consumption numbers, so range is not measured.

Dimensions and weight

Wheel size: not measured on both versions.

Ground clearance: 180 mm on both — no generation step, no version step.

Tank: 91 L on both.

Kerb weight: 2135 kg on the 164 hp 4.2 AT; 2160 kg on the 178 hp 4.2 AT. Difference: +25 kg on the 178 hp car.

Gross weight: 2830 kg on the 164 hp 4.2 AT. Not measured on the 178 hp 4.2 AT. Payload on the 164 hp car is 2830 − 2135 = 695 kg. Payload on the 178 hp car is not measured.

Kilograms per horsepower (kerb ÷ hp): 2135 ÷ 164 = 13.0 kg/hp on the 164 hp 4.2 AT; 2160 ÷ 178 = 12.1 kg/hp on the 178 hp 4.2 AT. The 25 kg penalty is more than offset by the 14 hp gain: specific load falls by 0.9 kg/hp (−6.9%).

Power-to-weight in hp per tonne of kerb: 164 ÷ 2.135 = 76.8 hp/t versus 178 ÷ 2.160 = 82.4 hp/t. The 178 hp 4.2 AT is 5.6 hp/t ahead.

Engine position: not measured on both.

Which version to choose

There is one generation and two 4.2 AT names. The decision is 164 hp versus 178 hp.

Choose the 4.2 AT 164 hp when the buyer needs numbers that were actually measured. It is the only version with top speed 177 km/h, city 24.1 / highway 14.8 / mixed 19.2 L/100 km, gross weight 2830 kg, and a 695 kg payload that can be calculated. It also has the higher torque: 301 Nm versus 297 Nm at the same 2500 rpm. Feeding is Carburetor, compression 7.5, kerb 2135 kg — 25 kg lighter. Power per litre is 38.7 hp/L. Specific mass is 13.0 kg/hp. Mixed range on 91 L is 474 km. If the use case is a Limousine that must be specified with speed, consumption, and gross weight, this is the version the data support.

Choose the 4.2 AT 178 hp when the buyer ranks peak output and specific power above a complete measured sheet. It is +14 hp, +10 kW, +3.3 hp/L (42.0 versus 38.7), +5.6 hp/t, and −0.9 kg/hp. Compression is 8.1 versus 7.5. Feeding is Central injection (single-point or single- point). Peak power arrives 250 rpm later (4750 versus 4500). The cost in the data is not a price — there is no price in the data — it is +25 kg kerb, −4 Nm, top speed not measured, 0–100 not measured, all three consumption figures not measured, and gross weight not measured. The extra 14 hp buys a lighter kg/hp ratio and a higher hp/L ratio; it does not buy a published speed, mpg, or payload.

What the two versions do not split: years (both 1968-01-01–1992-12-31), body (Limousine), displacement (4235), fuel (Gasoline, 95), cylinders (6 Inline, 2 valves), boost (No), gearbox (Automatic 3), drive (RWD), tank (91 L), clearance (180 mm), suspension (Independent, spring front and rear), brakes (Ventilated disc / Disc), bore and stroke (92.07 × 106). There is no AWD option, no second gearbox, no other displacement, and no later generation that “fixed” economy or weight.

Problems and reliability are not measured in these data; they cannot be used to pick a version.

Buy the 164 hp 4.2 AT if the sheet must be complete. Buy the 178 hp 4.2 AT if 14 hp, 42.0 hp/L and 12.1 kg/hp outweigh 4 Nm and a blank speed/economy/gross block. Both remain Daimler DS420 1 generation Limousine 4.2 AT cars; the name is the same, the power figure is the difference.