It really does depend on equipment needed to put in the boot, seats up or down etc. on the Tucson the hybrid system does lose the space saver wheel and replaced with a foam repair kit and overall loses 29litres of space compared to the none hybrid but the Tucson boot is on paper is already bigger than the Sportage and Kuga, even with losing 29ltr to the hybrid system the Tucson remains 28ltr bigger than the standard Kuga, but as suggested on another thread it’s all in the useable space and shape, but it really is a different vehicle to the Kia and worth a look on its on merits.