The Focus diesel is aimed at higher-mileage drivers — real-world economy is best on steady motorway runs. Modern Ford diesels from this era commonly have DPF/EGR systems and may use AdBlue (check for a separate filler cap); automatic gearboxes need their service history checked for fluid changes or software updates. At three years old it may still have part of the manufacturer’s warranty depending on mileage, so ask for the paperwork and any recall/service campaign records.

• DPF condition and regeneration history — look for frequent regens, heavy soot in the tailpipe or a persistent warning light (problematic if the car was used mainly on short urban trips).
• AdBlue filler and dosing system — confirm presence of filler cap, recent top-ups and no warning lights for the SCR system.
• Automatic gearbox behaviour and service history — check for smooth, prompt shifts, no hesitation or slip, and evidence of any gearbox fluid/service work or software updates.
• Turbocharger signs — listen for excessive whine or lag and check for blue/black smoke on cold start and under acceleration.
• Visible oil leaks around injectors/cylinder head and general under-bonnet condition (diesel injector leaks and oil seepage are more common than on petrols).