AC Aceca: which version to buy
The AC Aceca in this catalogue is one generation (1998–2000), a Coupe, and two petrol versions: 3.5 MT and 4.6 MT. Both are RWD, both weigh 1615 kg, both have a 90-litre tank and a 250 km/h top speed.
The AC Aceca in this catalogue is one generation (1998–2000), a Coupe, and two petrol versions: 3.5 MT and 4.6 MT. Both are RWD, both weigh 1615 kg, both have a 90-litre tank and a 250 km/h top speed. The buying choice is not “which generation” — there is only one — but which engine and gearbox package: a smaller turbo 8-cylinder that is stronger and quicker, or a larger naturally aspirated 8-cylinder that makes more torque, uses a shorter gearbox, and asks for 98 fuel instead of 95.
AC Aceca generations: what actually changed
There is 1 generation. It ran from 1998-01-01 to 2000-12-31. Body: Coupe. Version count: 2. No restyling is listed in the data, so there is nothing to treat as a mid-cycle refresh.
That means generation-to-generation arithmetic does not apply here. Weight did not move between versions (1615 kg on both). Tank size did not move (90 litres on both). Drive did not move (RWD on both). Front and rear suspension are Independent, spring on both. Front brakes are Ventilated disc on both; rear brakes are Disc ventilated on both (the catalogue spelling). Fuel consumption, CO2, eco class, gross weight, ground clearance, and wheel sizes are not measured on either version.
What did change is the engine and the gearbox: displacement, boost, power, torque, compression, bore × stroke, fuel grade, 0–100 time, and the number of gears.
Searches often mix this 1998–2000 Coupe with older Aceca names (Bristol, 1950s cars). Those cars are not in this dataset. The two versions below are the only ones to choose from in these figures.
AC Aceca specs: the two versions side by side
| Version | hp | Nm | Displacement (cm³) | Fuel | Cylinders | Layout | Boost | Gearbox | Drive |
|---|---|---|---|---|---|---|---|---|---|
| 3.5 MT | 354 | 407 | 3506 | Gasoline | 8 | V-shaped | Turbo | Manual, 6 | RWD |
| 4.6 MT | 326 | 427 | 4601 | Gasoline | 8 | V-shaped | No | Manual, 5 | RWD |
Both use Distributed injection (multi-point) and 4 valves per cylinder. Engine position is not measured on either version.
3.5 MT peaks at 354 hp (260 kW) at 6500 rpm and 407 Nm at 4000 rpm. Compression ratio is 8. Bore × stroke is 83 × 81. Fuel grade: 95.
4.6 MT peaks at 326 hp (240 kW) at 5800 rpm and 427 Nm at 4600 rpm. Compression ratio is 9.85. Bore × stroke is 90.2 × 90. Fuel grade: 98.
Engine comparison: what the extra displacement actually buys
The 4.6 MT is 1095 cm³ larger than the 3.5 MT (4601 vs 3506). That extra litre-plus does not buy more peak power. It buys 20 Nm more torque (427 vs 407) and it buys a naturally aspirated map: boost is No, not Turbo.
Peak power goes the other way. 3.5 MT has 28 hp more than 4.6 MT (354 vs 326) and 20 kW more (260 vs 240). It also revs the power peak 700 rpm higher (6500 vs 5800). Torque on 3.5 MT arrives 600 rpm earlier (4000 vs 4600).
Power per litre (hp ÷ displacement in litres):
- 3.5 MT: 354 ÷ 3.506 ≈ 101 hp per litre
- 4.6 MT: 326 ÷ 4.601 ≈ 71 hp per litre
The turbo 3506 cm³ unit is about 30 hp/l denser. That is the arithmetic of Turbo versus No on these two engines, not a styling difference.
Compression: 4.6 MT is 1.85 points higher (9.85 vs 8). That matches the fuel split: 4.6 MT is specified for 98, 3.5 MT for 95. If you want the lower octane, the numbers point at 3.5 MT. If you want the higher-compression, larger-bore naturally aspirated 8, the numbers point at 4.6 MT.
Bore × stroke: 3.5 MT is 83 × 81 (slightly oversquare). 4.6 MT is 90.2 × 90 (almost square, 0.2 mm more bore than stroke). The 4.6’s extra capacity is mostly bigger bore and a longer stroke, not a third engine architecture — both are 8, V-shaped, Gasoline, 4 valves per cylinder, Distributed injection (multi-point).
Gearbox: 6-speed vs 5-speed
Both are Manual and both are RWD. The split is gear count:
- 3.5 MT: 6 gears
- 4.6 MT: 5 gears
3.5 MT is the only version with a sixth ratio. Combined with 28 hp more and a 0.5 s quicker 0–100 (see below), the 6-speed is the performance pairing in this catalogue. 4.6 MT keeps five ratios on the larger, torquier engine. There is no Automatic in the data, so the buy is not “manual vs automatic”; it is 6 vs 5 on two different engines.
Performance and economy
0–100 km/h:
- 3.5 MT: 5.6 s
- 4.6 MT: 6.1 s
3.5 MT is 0.5 s quicker. That is the only acceleration gap in the file.
Top speed: 250 km/h on both. Extra power on 3.5 MT does not raise the listed maximum.
Fuel consumption (city, highway, mixed): not measured on 3.5 MT and not measured on 4.6 MT. CO2: not measured. Eco class: not measured. You cannot pick a version on mpg from this catalogue; the figure does not exist for either car.
What you can use as a fuel-related buying filter is grade: 95 on 3.5 MT, 98 on 4.6 MT.
AC Aceca weight and dimensions
Kerb weight: 1615 kg on 3.5 MT and 1615 kg on 4.6 MT. Gross weight: not measured on both. Ground clearance: not measured on both. Wheel sizes: not measured on both. Tank: 90 litres on both.
Weight does not help you choose a version; it is identical. What changes is weight per horsepower:
- 3.5 MT: 1615 ÷ 354 ≈ 4.56 kg per hp
- 4.6 MT: 1615 ÷ 326 ≈ 4.95 kg per hp
3.5 MT is about 0.39 kg/hp lighter on that ratio — same mass, 28 more hp. Torque per tonne (Nm ÷ (kg/1000)):
- 3.5 MT: 407 ÷ 1.615 ≈ 252 Nm per tonne
- 4.6 MT: 427 ÷ 1.615 ≈ 264 Nm per tonne
Here 4.6 MT wins by about 12 Nm/t. That is the clean split: 3.5 MT is the power-to-weight car; 4.6 MT is the torque-to-weight car.
Chassis items that do not differ and therefore do not decide the purchase: Independent, spring front; Independent, spring rear; Ventilated disc front; Disc ventilated rear; RWD; 90-litre tank.
Which AC Aceca version to choose
There is no second generation to “step up to.” The choice is 3.5 MT versus 4.6 MT.
Choose 3.5 MT if the numbers you care about are power, sprint, and gears. You get 354 hp vs 326 hp (+28 hp), 260 kW vs 240 kW (+20 kW), 5.6 s vs 6.1 s to 100 km/h (−0.5 s), a 6-speed Manual instead of 5, Turbo instead of No, 95 fuel instead of 98, and ~101 hp/l vs ~71 hp/l. Same 1615 kg, same 250 km/h, same 90-litre tank. You give up 20 Nm (407 vs 427) and you live with a lower compression ratio (8 vs 9.85).
Choose 4.6 MT if the numbers you care about are displacement, torque, and a naturally aspirated 8. You get 4601 cm³ vs 3506 cm³ (+1095 cm³), 427 Nm vs 407 Nm (+20 Nm), boost No, compression 9.85, bore × stroke 90.2 × 90, and ~264 Nm/t vs ~252 Nm/t. You give up 28 hp, 0.5 s on 0–100, the sixth gear, and you need 98 rather than 95. Top speed does not improve: still 250 km/h.
Do not choose on consumption, clearance, wheels, or gross weight. Those are not measured on either version. Do not choose on body style: both are Coupe. Do not choose on drive: both are RWD. Do not choose on kerb weight: both are 1615 kg.
A short rule from the arithmetic: if you want the quicker, more powerful, 6-speed Turbo Coupe, 3.5 MT is the one in the file. If you want the larger, torquier, 5-speed engine with no turbo and 98 fuel, 4.6 MT is the one. There is no third modification and no later generation in this catalogue to split the difference.