While Kia isn't a luxury brand, the K900 is a luxury car and so is the Stinger. The Genesis Sedan, especially 2015 and 2016, wasn't sold by a luxury brand, but it was a luxury car. If the Telluride doesn't offer more than the Toyota Highlander and Subaru Ascent, I'd be very surprised. I need to look more into the latest as I haven't been paying close attention. I'd be really disappointed though if the Telluride wasn't any better than the Highlander.
The Ascent does have much better low end torque and would not suffer from altitude loss. However, if you check out their forums, most owners in the real world are not seeing as good of MPG as it is rated for. I believe that the turbos are spooling so much that they are not getting the efficiency of the 4 cyl. In my Flex, I have the twin turbo, 3.5L V6 EB motor, in my previous I had the 3.5L NA motor. If I am light on the throttle, I can get as good of mileage out of my twin turbo as I did my NA, but I can hammer on it and have plenty of power, which I couldn't in my old one. I think were Subaru may have somewhat failed is that their base motor cannot properly power the weight of the Ascent without boost for much other then slow acceleration on flat or for downhill. I would really like to see the Telluride with a Turbo/Twin Turbo version of this motor. It clearly has enough power to move the vehicle that the turbos may not be required as often as they are on the Subaru. I actually think a small V8 would be a good application in vehicles this size - it would provide lower end torque and would hardly have to work to move the Telluride along. I am not a fan of the smaller motors being turbo'd to get the necessary power. More components to fail.
