De Tomaso Longchamp: which version to buy

The De Tomaso Longchamp was sold in one generation (1972–1989) as a Coupe with two versions that share the same engine and differ mainly in gearbox, mass, and measured pace: 5.8 MT (Manual, 5 gears) and 5.8 AT (Automatic, 3 gears).

The De Tomaso Longchamp was sold in one generation (1972–1989) as a Coupe with two versions that share the same engine and differ mainly in gearbox, mass, and measured pace: 5.8 MT (Manual, 5 gears) and 5.8 AT (Automatic, 3 gears). Both make 330 hp (243 kW) at 6000 rpm and 460 Nm at 4750 rpm from a 5766 cm³ Gasoline V-shaped 8-cylinder with 2 valves per cylinder, Carburetor feed, No boost, 102 × 89 mm bore and stroke, RWD, and an 80-litre tank. The buying choice is not “which engine” — it is whether a 5-speed Manual and the faster measured figures of 5.8 MT outweigh the 3-speed Automatic of 5.8 AT.

Longchamp versions compared: 5.8 MT vs 5.8 AT

There is no second generation to “buy newer.” Both versions ran 1972-01-01 to 1989-12-31 in the same Coupe body. Ground clearance is not measured for either. Wheel sizes are not measured for either. CO2 is not measured. Eco class is not measured. Engine location is not measured. Compression ratio is not measured.

What the numbers do show:

VersionhpNmcm³FuelCylindersLayoutBoostGearboxDrive
5.8 MT3304605766Gasoline8V-shapedNoManual 5RWD
5.8 AT3304605766Gasoline8V-shapedNoAutomatic 3RWD

Power per litre is identical: 330 hp ÷ 5.766 L ≈ 57.2 hp/L. Torque per litre is identical: 460 Nm ÷ 5.766 L ≈ 79.8 Nm/L. Fuel grade in the data is 95 for both. Suspension is Independent, spring front and Independent, spring rear on both. Front brakes are Ventilated disc; rear brakes are Disc on both.

The arithmetic gap is gearbox, mass, and performance — not power.

What the extra Automatic buys (and what it costs in the numbers)

5.8 AT does not add horsepower, torque, displacement, or tank size versus 5.8 MT. It swaps Manual 5 for Automatic 3.

Measured cost of that swap:

Weight per horsepower:

The Automatic is only about 0.3% heavier per horsepower. The 1-second 0–100 gap is therefore not explained by mass; it lines up with Automatic 3 versus Manual 5 at the same 330 hp and 460 Nm.

Useful load (gross minus kerb):

5.8 MT carries 5 kg more useful load at the same 2275 kg gross.

If the question is “what does Automatic buy in this catalogue,” the data answer is: a 3-speed Automatic, 5 kg more kerb mass, 5 kg less useful load, 1 s slower to 100 km/h, and 5 km/h less top speed. It does not buy more power, a larger tank, different drive, different brakes, or a later generation.

Performance and mpg: which Longchamp is quicker and which has figures

5.8 MT is the only version with a full consumption set in the data:

5.8 AT:

Do not treat missing mpg on 5.8 AT as “the same as MT” or as “better.” It is not measured. Mixed 15 on 5.8 MT with an 80-litre tank implies a mixed range of 80 ÷ 15 × 100 ≈ 533 km on that figure alone; the same sum cannot be written for 5.8 AT because mixed consumption is not measured.

Highway vs city on 5.8 MT: city 21 is 11 above highway 10 (more than double highway use). Mixed 15 sits 5 above highway and 6 below city.

Speed per horsepower is not a catalogue field; the measured tops are 240 km/h (5.8 MT) and 235 km/h (5.8 AT) at the same 330 hp.

Dimensions, weight, tank: nothing to choose except 5 kg

Ground clearance: not measured (both). Wheels: not measured (both). Tank: 80 litres (both). Gross: 2275 kg (both). Kerb: 1815 kg (5.8 MT) vs 1820 kg (5.8 AT).

There is no generation-to-generation weight cut and no restyle with a different tank. A buyer who wants lower kerb mass, higher useful load, and measured 0–100 of 6 s is pointed at 5.8 MT by arithmetic, not by a later body.

Kerb as a share of gross:

Reliability, problems, specs — what this data can and cannot decide

This catalogue row does not list failure rates, spare prices, or typical faults. Reliability and “problems” cannot be ranked between 5.8 MT and 5.8 AT from these numbers. Shared hardware in the data: Gasoline 5766 cm³, 8 cylinders, V-shaped, 2 valves per cylinder, No boost, Carburetor, 95 fuel, RWD, Independent spring suspension both ends, Ventilated disc front, Disc rear, 80-litre tank, 330 hp / 460 Nm, 1972–1989 Coupe.

What can be ranked:

1. Pace: 5.8 MT (6 s, 240 km/h) over 5.8 AT (7 s, 235 km/h). 2. Mass / payload: 5.8 MT (1815 kg kerb, 460 kg useful) over 5.8 AT (1820 kg, 455 kg). 3. Documented mpg: only 5.8 MT (21 / 10 / 15). 5.8 AT city, highway, and mixed are not measured. 4. Shift count: Manual 5 (5.8 MT) vs Automatic 3 (5.8 AT).

If the goal is the quicker Coupe with published consumption, 5.8 MT is the version the numbers support. If the goal is Automatic, 5.8 AT is the only Automatic in this model; accept +1 s to 100 km/h, −5 km/h top speed, +5 kg kerb, and mpg not measured.

Which version to choose

Choose 5.8 MT when the decision is driven by measured performance and economy: 330 hp and 460 Nm through a Manual 5, RWD, 6 s to 100 km/h, 240 km/h, kerb 1815 kg, mixed 15, city 21, highway 10, tank 80. It is the lighter of the two by 5 kg and the only one with consumption written down.

Choose 5.8 AT only for Automatic 3. Engine output matches 5.8 MT exactly (330 hp at 6000 rpm, 460 Nm at 4750 rpm, 5766 cm³, Gasoline, V-shaped 8, 2 valves per cylinder, No, Carburetor). The data does not give it more power, a larger tank, AWD, or a later generation. It is 5 kg heavier at the kerb, 1 s slower to 100 km/h, 5 km/h slower at the top, and its fuel use is not measured.

There is no third version and no second generation. Power per litre (~57.2 hp/L) does not break the tie. Gearbox, the 6 vs 7 second 0–100 split, and whether mixed mpg is measured or not measured — those three facts are the whole buying comparison for the De Tomaso Longchamp in this catalogue.