According to the specs on interior dimensions listed on fueleconomy.gov, the Ioniq is actually bigger - 96 cu ft passenger and 23 cu ft luggage volume, vs. 97 c

According to the specs on interior dimensions listed on fueleconomy.gov, the Ioniq is actually bigger - 96 cu ft passenger and 23 cu ft luggage volume, vs. 97 cu ft passenger and 15 cu ft luggage for the Model 3. So they've sacrifised range by installing less batteries, gaining more luggage space, lower weight and lower price.