Which Daimler X308 version to buy
Buy the 284 hp 4.0 AT if you want the lighter kerb, the higher compression ratio, and the larger payload. Buy the 363 hp 4.0 AT if you want the extra 79 hp, the extra 130 Nm, the 1.6 s shorter 0–100 run, and the 10 km/h higher top speed, and you accept 70 kg more kerb mass.
Buy the 284 hp 4.0 AT if you want the lighter kerb, the higher compression ratio, and the larger payload. Buy the 363 hp 4.0 AT if you want the extra 79 hp, the extra 130 Nm, the 1.6 s shorter 0–100 run, and the 10 km/h higher top speed, and you accept 70 kg more kerb mass. Both versions are Gasoline, 8 cylinders, V-shaped, 4 valves per cylinder, Distributed injection (multi-point), Automatic with 5 gears, RWD, 81 L tank, 130 mm ground clearance, Independent, spring suspension front and rear, and Disc brakes front and rear. Fuel consumption, CO2, eco class, wheel sizes, and engine location are not measured on either version, so they cannot decide the purchase.
Specs compared: both 4.0 AT versions
| Version | hp | Nm | cm³ | Fuel | Cylinders | Layout | Boost | Gearbox | Drive |
|---|---|---|---|---|---|---|---|---|---|
| 4.0 AT (284 hp) | 284 | 375 | 3996 | Gasoline | 8 | V-shaped | No | Automatic 5 | RWD |
| 4.0 AT (363 hp) | 363 | 505 | 3996 | Gasoline | 8 | V-shaped | Turbo | Automatic 5 | RWD |
Both 4.0 AT lines use 95 fuel. Peak power of the 284 hp 4.0 AT is 209 kW at 6100 rpm; peak power of the 363 hp 4.0 AT is 267 kW at 6150 rpm — 58 kW more at only 50 rpm higher. Peak torque of the 284 hp 4.0 AT is 375 Nm at 4250 rpm; peak torque of the 363 hp 4.0 AT is 505 Nm at 3600 rpm — 130 Nm more and 650 rpm earlier.
Engine: what the extra 79 hp buys
Displacement is identical: 3996 cm³ on both 4.0 AT versions. Specific output is therefore 284 ÷ 3.996 = 71.1 hp per litre on the 284 hp 4.0 AT, versus 363 ÷ 3.996 = 90.8 hp per litre on the 363 hp 4.0 AT. The turbocharged car extracts 19.7 hp more from each litre.
The 284 hp 4.0 AT has boost No, compression 10.8, and bore × stroke 86 × 86. The 363 hp 4.0 AT has boost Turbo, compression 9, and bore × stroke 86.9 × 86. Stroke is the same 86 mm; bore is 0.9 mm larger on the Turbo engine. Compression is 1.8 points lower on the Turbo 4.0 AT, which is the arithmetic counterpart of adding Turbo while keeping Gasoline 95 and Distributed injection (multi-point).
Valves per cylinder are 4 on both. Cylinder count is 8 and layout is V-shaped on both. Engine location is not measured on both, so it is not a differentiator.
Performance and mpg: 0–100, top speed, consumption
The 284 hp 4.0 AT reaches 100 km/h in 7.3 s and is limited to 240 km/h. The 363 hp 4.0 AT reaches 100 km/h in 5.7 s and is limited to 250 km/h. The Turbo version is 1.6 s quicker to 100 km/h (about 22% less time) and 10 km/h faster at the limiter.
City, highway, and combined fuel consumption are not measured for the 284 hp 4.0 AT and not measured for the 363 hp 4.0 AT. CO2 is not measured on both. Eco class is not measured on both. MPG cannot be compared from this catalogue: the figure does not exist in the data for either version. Anyone choosing on economy is choosing without a measured number.
Tank volume is 81 L on both 4.0 AT versions, so range differences, if any, would come only from unmeasured consumption, not from tank size.
Dimensions, weight, and ground clearance
Kerb weight is 1730 kg on the 284 hp 4.0 AT and 1800 kg on the 363 hp 4.0 AT — 70 kg, or 4.0%, more on the Turbo car. Gross weight is 2260 kg on both. Payload is therefore 2260 − 1730 = 530 kg on the 284 hp 4.0 AT and 2260 − 1800 = 460 kg on the 363 hp 4.0 AT. Choosing the 363 hp 4.0 AT costs 70 kg of payload.
Mass per horsepower is 1730 ÷ 284 = 6.09 kg/hp on the 284 hp 4.0 AT versus 1800 ÷ 363 = 4.96 kg/hp on the 363 hp 4.0 AT. The Turbo version carries 1.13 kg less per horsepower despite the 70 kg kerb penalty, because 79 extra hp more than offsets 70 extra kg.
Ground clearance is 130 mm on both. Wheel sizes are not measured on both. Front suspension is Independent, spring on both; rear suspension is Independent, spring on both. Front brakes are Disc on both; rear brakes are Disc on both. Chassis hardware in the data does not split the two 4.0 AT versions.
Generations: what changed (and what did not)
The Daimler X308 has 1 generation, sold from 1997-01-01 to 2003-12-31 as a Sedan, with 2 modifications. There is no second generation to compare on years, body, or drivetrain. Both 4.0 AT versions occupy the same dates: 1997-01-01 to 2003-12-31. Restyling is not listed as a separate generation in the data, so it is not treated as one.
What “changed” inside this single generation is only the pair of 4.0 AT engines: 284 hp / 375 Nm / boost No versus 363 hp / 505 Nm / boost Turbo. Gearbox (Automatic, 5), drive (RWD), body (Sedan), tank (81 L), clearance (130 mm), gross weight (2260 kg), and the Independent, spring / Disc hardware stay the same in the numbers given.
Reliability and problems: what the numbers can and cannot say
This catalogue does not list failure rates, recall counts, or typical faults. Reliability and problems cannot be scored from the given fields. What the numbers do show is where the two 4.0 AT versions differ in load:
- The 363 hp 4.0 AT runs 79 hp and 130 Nm more through the same Automatic 5 and RWD layout, at 70 kg higher kerb mass.
- The 284 hp 4.0 AT runs higher compression (10.8 versus 9) without Turbo.
- Both share 3996 cm³, Gasoline, 8 cylinders, V-shaped, 4 valves per cylinder, Distributed injection (multi-point), and 95 fuel.
Those are mechanical differences, not reliability scores. Do not read a verdict about durability into a blank field.
Which 4.0 AT to choose, in numbers
Choose the 284 hp 4.0 AT when the arithmetic that matters is mass and payload: 1730 kg kerb, 530 kg payload, 6.09 kg/hp, compression 10.8, boost No, 7.3 s to 100 km/h, 240 km/h. You give up 79 hp, 130 Nm, 1.6 s, and 10 km/h.
Choose the 363 hp 4.0 AT when the arithmetic that matters is output and acceleration: 363 hp, 505 Nm at 3600 rpm, 90.8 hp/L, 4.96 kg/hp, 5.7 s to 100 km/h, 250 km/h, boost Turbo. You add 70 kg at the kerb and lose 70 kg of payload, and you run compression 9.
There is no third Daimler X308 version in the data, no other gearbox, no other drive, and no other generation. Fuel consumption, CO2, eco class, wheels, and engine location remain not measured on both 4.0 AT lines, so they cannot break a tie. The purchase is 284 hp versus 363 hp under one name.