In "comfort" it will send up to 50% to the front. In "sport" it will send up to 20% to the front. As for the "eco" setting, I don't know. It doesn't say in the manual. So, if you want a heavily RWD biased drive, set your AWD mode to "sport" in "custom", or just use the "sport" setting, if you don't mind the fake engine sounds. If you're heading into rain, and want better stability, set AWD drive to "comfort" mode in "custom" or just change the drive mode to "comfort". Personally, I love the steering feel in "sport", but don't like fake engine noise (I want to actually hear the engine), so my general driving setting is "custom" with steering feel set to "sport", fake engine noise off, and all other settings to "comfort". I'd like there to be a second custom mode, for my "sport" mode, without the engine noise, or just a way to generally turn off the fake engine noise in all modes.