I'm not an expert on these things but I always think the right seems a little hotter as you tend to be gripping the throttle and trying to do things gently? That's my theory. Also. the heated grips are controlled by some electronics in a small cover which if installed incorrectly can invite water in and give problems. I was told by the dealer that the circuit board meters the outputs and can adjust what it receives and delivers. Maybe this explains, I don't know??