One problem related to gas recirculation valve (egr valve) has been reported for the 2018 Hyundai Tucson. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2018 Hyundai Tucson based on all problems reported for the 2018 Tucson.
The vehicle when temp is set to high heat then switched to 75 degrees there is a strong coolant smell that comes from the hvac system. It makes me nauseous while driving. Took to dealership where they said they can duplicate the issue. Called Hyundai customer care and they called once and I missed it and emailed them and called and no one has contacted me back. Coolant is hazardous to breath in and they don't take it as a serious matter.