I know more than 10 well known cases who got major engine issues with Kia and Hyundai diesel SUVs. It exactly happened after 100,000km. Mostly they had to replace the engine (and the gearbox) or overhaul it.
So, if you're planning to go for a Korean diesel SUV, make sure the mileage is very low.
X-Trail this model also well know some transmission issues.
Best option is Outlander in that case. If you can go for a PHEV ( with a good battery condition ) model, it'll be economical as hell.
NOTE : I'm not an expert in this subject but know some friends who have these SUVs