Any mention of the P+ configuration? Does the P85D include P+ tire/suspension mods, or will there also be a P85D+, or do we not know anything yet?
Others have answered but to summarize and add flavor based on drivetrain engineer talks…
The P+ is entirely replaced by the P85D. It does have (re)tuned suspension, tweaked similar to the P+ but tuned taking into account the different vehicle dynamics of the D. You could tell from talking to them that they've spend considerable time thinking about the specifics and trying out things, not just for the dual motor configs in general, but for the dual sized motor performance version in particular.
He told me he thought they had changed the tires again, but was unsure on what the final thing they landed on was, then we both went and stared at the rear tires blankly for a moment before getting distracted and going down a different path of the conversation
He did say they kept a staggered config, and actually said the rear tires were even wider than the +, which surprised me and makes me wonder if what he meant was just that they were *still* staggered and wider than the front. All this came up when I was asking if they had switched from the PS2s to the PSS's. Unfortunately due to the blank staring, and general excitement level about everything, I didn't come away with a final answer
Other items not touched on in Elon's announce, but discussed in passing with employees:
Different modes range/normal/insane (think now called normal/performance/insane) don't feel that much different between first 2, but 1st one does mostly use the front motor while cruising. Power balance is still dynamic in all modes and even in range mode, when you push the go pedal, power shifts and performance happens. Sounded like vehicle dynamics would be "slightly" affected in range mode though, in terms of handling in curves, etc., due to the default bias. I think we'll just have to get them on the road to really feel how much the modes matter. Hate having to choose one and feeling like a spur of the moment need might make me feel like I chose the wrong one, but he assured me the effects were slight. It really seemed like they had put a *lot* of work into vehicle dynamics, and that they expect to continue to make it better via updates. We talked about the stronger regen available, and the improvements to tire wear. There was some discussion of the potential of a software dial for regen limits or even a hardware option for increasing regen beyond the off throttle limit (but that was a pet project vs. something to expect). The just dialing up the limit had limits due to vehicle dynamics leading to a potentially unsafe condition at extreme limits of regen, but it sounded like there is the real possibility to have more control over the regen range/curve than just low/normal at some point, via software update.
The front motor was chosen because it gave the best performance relative to weight based on the fact that under heavy acceleration, weight shifts to the rear and had they used the bigger rear motor in the front too, it would just have been traction limited without really buying you extra acceleration. I mentioned the mythical dual current P85 motor engineering/test S and the sub 3 second 0-60's it supposedly got, but he didn't really have anything to say about that beyond seeming surprised that it'd actually be a performance improvement over the released design, based on traction limits and "safe" power draw limits from the battery. The released P85D set up is power limited but close to the traction limits. The delta in performance between the other D variants and the RWD versions is much smaller (but still there!) due to the 2 smaller motors vs. 1 big 1 small, but the vehicle dynamics gains are still all there and subject to improvement/refinement as they do software updates.
Relevant to P85D -> P85D+, and future proofing in general, I explained I was a Roadster 1.5 owner (and lived through the big changes as the 2 and 2.5 were released) and asked how solid/final the configs and engineering was for the P85D in terms of likely changes over the course of the next couple years. We went into quite a few different aspects of the platform, but bottom line was it sounded like it wasn't likely there would be an even more powerful drivetrain available "soon" and that the design was solid and unlikely to change for a couple years. A lot of effort was spend on "getting it right", at the chassis, drive train, and sensor suite level such that it would be a stable base for the X (though asking/saying anything about the X was strictly off limits) and S through to the Model 3 era. He expected any changes they made to be more about lowering their cost or improving reliability (again to lower their cost of warranty work) vs. new functionality or higher power. No promise new battery packs or tech would or would not be available that would obsolete the current packs, but I definitely got the impression it wouldn't happen in the next year (implication to me therefore is that the X's will not have new battery options in 2015 - though again there was no faster way to shut down a Tesla employee than to ask about the X, "strict orders", etc.)
My bottom line is I expect continued improvements and upgrades in the interior over the course of the next year, but nothing new in the drivetrain. Maybe some additional suspension tweaks, but I think those would tend to be retrofittable at a service center. Definitely expect performance tweaks and improvements to the dual motor intelligence but fully expect it to be via software updates. I suspect but had no confirmation that there will be more paint options coming for S and X, but probably not in the next couple/three months. Certainly not for the first P85D's