The Mercedes‑Benz S 400 is a mid‑level S‑Class trim that offers flagship‑grade luxury and tech with a slightly smaller engine than the S 450/S 500, aimed at buyers who want S‑Class presence and refinement but at a lower price and (usually) better fuel efficiency.

What S 400 typically is

• A four‑door, five‑seat luxury sedan on the S‑Class platform (W221, W222, or W223 depending on year), with a formal greenhouse, large rear doors, and a very low boot lip.

• Boot space is about 18–19 ft³ (≈500–550 litres), with a fuel tank around 70–80 litres, depending on variant and market.

• Different engine family to S 450/S 500: some S 400 generations use a 3.0‑litre V6 (often 3497–3500 cc) while others may use a 3.0‑litre inline‑six or even a hybrid‑assisted powertrain (S 400 Hybrid / BlueHYBRID) that blends a V6 with an electric motor.

Typical engine and performance (main S 400 variants)

Across common S 400 builds (especially W221–W222):

• Engine: 3.0‑litre V6 turbo (M276‑family derivatives), in many cases around 3.5 L V6 turbo producing roughly 306–330 hp and 370–480 Nm torque, depending on tune and spec.

• 0–100 km/h: Usually in the 5.5–6.5 second range, with a governed top speed of 250 km/h (155 mph).

• Transmission: 7‑ or 9‑speed automatic (7G‑TRONIC or 9G‑TRONIC), with rear‑wheel drive or 4MATIC all‑wheel drive depending on market and year.

• Fuel economy: Around 7–8 km/l in real‑world mixed driving on many petrol‑only S 400s; hybrid S 400 variants can be slightly better, especially in city use, at the cost of added complexity.

Key features and tech

The S 400 keeps the S‑Class halo feel:

• Digital instrument cluster plus large central screen (MBUX or older COMAND depending on generation).

• Heated leather seats, sunroof, keyless entry, panoramic camera, surround‑view system, sun‑blind for rear windows, and advanced lighting.

• Safety suite: multiple airbags, ABS, ESP, Attention Assist, Active Brake Assist, PRE‑SAFE, cross‑traffic alert, and other S‑Class‑standard aids, giving high safety‑rating credentials.

• Comfort touches: power front seats, multi‑zone climate, often power rear sides and rear‑seat comfort packages on higher‑spec builds.

Where it fits in the lineup and pricing

• Positioning:

  • Sits below S 450 / S 500 / S 560 / S 580 / AMG S 63 in performance and prestige but above base S 350/S 350d in many markets.

  • A good value‑entry into an S‑Class, especially the S 400 Hybrid / BlueHYBRID versions that offer S‑Class comfort with a slightly more economical powertrain.

• Pricing hints:

  • In India, older S 400 units (2012–2021) often listed around ₹1.3–1.4 crore on‑road, with hybrid‑badged variants sometimes higher due to tech.

  • In African and GCC markets, spec‑heavy S 400s can trade in the multi‑million local‑currency bands used, with hybrid‑spec cars often commanding a premium over simple petrol S 400s.

Reliability and considerations

• The S 400 is comfort‑oriented and well‑built, but like other S‑Classes it can be expensive to fix when electronics, air suspension, or high‑tech modules go wrong.

• Hybrid S 400 models add battery and inverter complexity, so service history and battery‑health records are important for used‑car buyers.

• Reasonable maintenance intervals, especially oil changes, fluid refreshes, and software updates, greatly improve long‑term reliability and ownership satisfaction.

If you tell me whether you’re focused on S 400 petrol, S 400 Hybrid/BlueHYBRID, or a specific market (e.g., Kenya, UAE, India), I can give you a spec‑style table plus a tailored pre‑buy checklist for your region.