This questions is specifically about the base suspension, not the air suspension. It just occurred to me - I ordered air suspension because the 2015 70 rwd I spent a week renting a few months back had the regular springs/shocks and I found the ride to be too jouncy and rough. But I just looked up curb weights a minute ago and I believe the 90D which I ordered should be about 350lbs heavier than that rwd 70. So, if the springs and shocks are the same, the extra mass should make the car ride smoother even with the base suspension. Does anyone know if this is true? Or is the base suspension tuned to have higher spring rates and firmer shocks when you go up the scale to the heavier dual motor and more battery versions, thus negating what would otherwise be the "ride smoothing" effect of the extra 350lbs. As a side note, I would think that a 70 rwd would feel more nimble than a P85D if they had the same suspension - 350lbs is enough to notice a difference.