Ford Focus IV (DEH) (2018 – 2025)

Reliability score : 6.8/10

The Ford Focus Mk4 (internal code DEH) was introduced in 2018, built on Ford's new C2 platform. It brought significant improvements in interior space, weight reduction (up to 88 kg lighter), and torsional rigidity compared to its predecessor. Renowned for its class-leading driving dynamics, the Mk4 offers a sharp, engaging chassis. A mid-cycle facelift was introduced in 2022, featuring a redesigned front fascia, standard LED headlights, and the introduction of the SYNC 4 infotainment system with a massive 13.2-inch screen. While this report focuses heavily on the diesel powertrains (EcoBlue), the Focus also offered a wide array of petrol (EcoBoost) and mild-hybrid (MHEV) options. Production is slated to end in 2025 as Ford's Saarlouis plant winds down operations, marking the end of the Foc

✅ Strengths

Class-leading chassis dynamics and steering feel
Spacious interior, especially rear legroom and estate boot capacity
Excellent SYNC 4 infotainment system on post-2022 facelift models
Very frugal diesel engines on long highway journeys
Strong safety equipment and Level 2 autonomous driving aids (Co-Pilot360)

⚠️ Weaknesses

Catastrophic failure risk on early 1.5 EcoBlue diesels (8mm camshaft chain)
Wet belt degradation risks on non-MHEV 1.0 EcoBoost engines
Interior plastics feel cheap in lower trims compared to VW Golf or Peugeot 308
8-speed torque converter automatic can be jerky and hesitant at low speeds
AdBlue system fragility on all diesel variants

🎯 Verdict

The Ford Focus Mk4 is arguably the best-driving car in its class, offering a brilliant blend of comfort and agility. However, as an independent expert, I urge extreme caution regarding the 1.5 EcoBlue diesel. Unless you have documented proof that the 8mm camshaft chain has been upgraded to the 10mm version, it is a ticking time bomb. The 2.0 EcoBlue is safer but requires a strict highway diet to avoid DPF/oil dilution issues. If you must buy a Focus Mk4, the smartest choices are the 1.0 EcoBoost MHEV (2020+) which utilizes a timing chain, or the robust 1.5 EcoBoost. Always negotiate hard on diesels without perfect, Ford-specific service histories.