A manual Hyundai i40 1.6 or 1.7 CRDi with every oil change stamped in its book is the lesser risk; don't touch a diesel with gaps in its servicing or a whining turbo, because oil-starved turbos are a known fault.
2 known faults, 1 rated high severity in our database; owners report 45.7 mpg, 81% of the official figure. Everything below is built from that data and the archived owner history, not from a press car.
Found a Hyundai i40 for sale? Check the advert before you go and see it
Paste the Hyundai i40 advert and we read it against its known faults, the MOT history and the DVLA record, then tell you what to ask the seller and what to look at on the day. Free, about a minute, no card.
Check a Hyundai i40 advert (free) →The i40 to go for is a manual 1.6 or 1.7 CRDi whose oil has been changed on time, every time, with the paperwork to show it. The 1.6 and 1.7 CRDi diesels built between 2010 and 2018 carry a known High fault: carbon from skipped oil changes blocks the turbo's oil feed pipes and strainers, and the turbo dies, usually between 70,000 and 120,000 miles.
That makes the service book worth more than the mileage or the trim. A car with missed or stretched oil changes that's already heading into that 70,000 to 120,000 mile window is the one to leave. Nothing on record covers any other i40 engine, and that's a gap in what's known rather than a clean bill of health.
Pick a manual over an automatic where you can. The dual-clutch box fitted to the 1.7 CRDi from 2015 to 2018 is a known source of shudder and worn clutches, and two owners reported earlier automatics that wouldn't engage their gears. Nothing on record describes cars built after 2016, so don't assume a later one's had its weak spots fixed.
No i40 engine on record can be called safe: the 1.6 and 1.7 CRDi diesels share a known High turbo fault, caused by oil feed pipes and strainers clogging with carbon when oil changes are skipped. It shows up between 70,000 and 120,000 miles as a siren-like whine from the turbo, lost power and blue exhaust smoke, so a diesel's only as good as its oil-change record.
The gearbox is the other choice that matters, and the manual's the one to have. From 2015 to 2018 the 1.7 CRDi 141 was offered with a dual-clutch automatic that's known to shudder moving off, hesitate pulling out of junctions and wear its clutches, sometimes dropping into limp mode. One owner of a 2016 car complained of exactly that judder, and a 2015 car with stop-start stalled three times on the move.
Earlier automatics have two reports against them: a 2011 six-speed car with a full dealer history and 45,000 miles wouldn't engage reverse or hold neutral, and another owner couldn't move their automatic out of Park. The manual isn't spotless either, since manual cars built in 2014 had a clutch problem a dealer admitted was a design fault, so try every gear.
Go through the service record before you drive it. On a 1.6 or 1.7 CRDi you want oil changes on schedule with no gaps, because that's what keeps the turbo's oil feed clear. With the engine running, listen for a whine or siren noise from the turbo, feel for a flat spot when you accelerate, and watch the exhaust for blue smoke.
On a manual, see whether the clutch needs to go right to the floor before a gear engages, and pick first, second and reverse several times from rest; a 2014 car that baulks matches the clutch fault on that year. On a dual-clutch automatic, pull away in first several times and out of a junction, feeling for shudder or hesitation, and ask for receipts for any clutch work.
Look along the roof. Stone chips on the front edge of a 2011 Tourer's roof let rust in, and a 2016 car had rust spots round its panoramic roof at 22 months old. Check both LED daytime running strips work, since one failed on a 2013 Tourer and the whole headlight had to be replaced, and apply the electric parking brake a few times.
Sit in traffic long enough to see stop-start cut the engine and restart it cleanly. On an October 2015 car the battery failed, the owner paid £329 for a new one, and stop-start gave up after a year. A January 2015 Tourer also produced clouds of smoke three times when its particulate filter regeneration went wrong, so ask what's been done on that front.
Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.
It's a sound buy as a manual 1.6 or 1.7 CRDi with an unbroken oil-change record, and one to pass on as a diesel with patchy servicing or a dual-clutch automatic that shudders. The Tourer estate gets judged on exactly the same things.
The turbo is the big risk on the diesels. Skipped oil changes let carbon block the oil feed pipes and strainers, starving the turbo until it fails, usually between 70,000 and 120,000 miles. A siren-like whine, lost power or blue smoke means it's on its way, and no amount of low mileage makes up for missing oil changes.
Gearboxes are the next thing. The dual-clutch automatic on 2015 to 2018 1.7 CRDi cars is known to judder and wear its clutches, a 2011 six-speed automatic wouldn't select reverse at 45,000 miles, and manual cars built in 2014 had a clutch fault that made gears hard to find. Beyond that, owners have reported roof rust from stone chips, a failed LED headlight strip and a parking brake that stuck on.
Real-world economy on this generation: Hyundai i40 Tourer 46.8 mpg, Hyundai i40 44.4 mpg.
Sellers rarely admit these faults outright
Paste any Hyundai i40 advert and we check it against the faults, the MOT record and these figures in seconds.
Check an advert now (free) →Owners report 45.7 mpg across the Hyundai i40 engines with data, about 81% of the official figure, from 457 submissions.
Hyundai i40 Real MPG by engine →A manual Hyundai i40 1.6 or 1.7 CRDi with every oil change stamped in its book is the lesser risk; don't touch a diesel with gaps in its servicing or a whining turbo, because oil-starved turbos are a known fault. Our database holds 2 known Hyundai i40 faults, 1 rated high severity, and the sections above say which generation and engine carry them.
Go through the service record before you drive it. Read the MOT history for repeat advisories and ask for invoices for any work the seller mentions. Then paste the advert into the free check, which reads it against every known Hyundai i40 fault before you travel.
Owners report 45.7 mpg on average, about 81% of the official figure, from 457 submissions. The known faults page lists a rough repair cost against each fault. Hyundai i40 Real MPG by engine.
If you used the Honest John car-by-car reviews before the site closed in 2026, this is where the Hyundai i40 buying advice now lives. It is written from the archived owner reports and model notes (archived page, 22 items read for this model), our own known-faults database, the confirmed service intervals and the Real MPG figures. Every number on the page comes from that data, not from the text. The same data feeds our free advert check.
CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services. What happened to Honest John, and where each feature lives now.
The Hyundai i40 is one decision. Reading the advert, the history and the seller are the rest, and these cover them.
Looking at a Hyundai i40 right now? Check the advert before you go and see it.