The 2012 i40 commonly uses Hyundai's 1.7 CRDi diesel with a manual gearbox — a dependable, economical package but one that dislikes lots of short urban trips because of DPF and EGR soot buildup. Parts and servicing are straightforward in Ireland and independent garages can keep running costs reasonable; confirm whether the car is the saloon or Tourer (estate) as both were sold in this generation.

• DPF condition and regeneration history — ask for evidence of recent long motorway runs or inspect for frequent DPF warning lights/smell of soot.
• EGR/intake soot build-up — watch for rough idle, loss of low‑end power or heavy smoke on cold acceleration.
• Turbo health and smoke check — test full‑throttle acceleration for smooth spool, no loud whining and minimal smoke.
• Clutch and gearbox feel — check for slipping, high bite point or judder and listen for dual‑mass flywheel rattles on engagement.
• Underbody and rear wheelarch/boot floor corrosion — inspect suspension mountings and boot area where road salt causes rot on older cars.