New 90D Feels Loose Above 75MPH

Sounds like an alignment or a wheel balance issue. I periodically hit 75 or 80mph in traffic each day (for limited stretches of the freeway) and I don't ever recall ever feeling a different sensation from the wheel. Now I do have the steering wheel set to to the heaviest weight so perhaps that is masking something.

 

Same here. Mine feels solid at 80 mph and my steering and auto suspension are set at standard.

 

The car should feel as stable at 80 as it does at 40. I have had this discussion with my Mercedes colleagues, who swear up & down that factory alignment is perfect, and I expect that Tesla uses similar alignment equipment at its plant. But still, sometimes alignment goes out of whack sometime later - hard to pinpoint where; this leads to handling problems and abnormal tire wear. Maybe something moves a little bit during shipping or initial driving (track test at factory?)- maybe something settles as a stress built into the system wears in. Anyway, if it was me, I would have this checked.

 

If you're coming out of a car that didn't have tires as wide as 245mm, you might not have experienced how some of the roads you travel have gullies. Camber can makes this a lot worse, but simply using wider tires can make a car feel like it steers itself, somewhat.

 

I have a recent P90D with about 2k miles on it and have had it up to 100 mph with no loose feeling. Definitely should be checked.

 

Check lug nut torque (should be 175 Nm)

 

Going to echo the recommendations for an alignment. My vehicle felt a little "loose" at higher speeds and the alignment cleared up those issues.

 

I've never felt anything other than complete stability with our car. I'd suggest you get this checked sooner rather than later.

 

Give it a few more weeks. My P85D felt unstable at highway speeds particularly changing lanes quickly when I first took delivery. I don't notice it anymore (now with 5k miles) and think it has to do with new tires breaking in. I have the Contisilent tires 245/35/21 all around. What do you have and how many miles on them?

 

"Old" P85D feels fine up to (at least) 145mph.

Note that sometimes it's the road quality at issue.

Edit:
In light of TEUNTSLA's comment, noting that my steering setting is "Sport".

 

Coming from mercedes to Tesla i found a similar feeling on occassion. switch the power steering to sport from comfort and you will have more feel in the steering wheel. i find the comfort setting does this. just my 2 cts.

 

Grooved highway?? Sometimes this can cause the car to feel like it is wandering.

 

Mine is stable at over 110, with steering at comfort.

Or else I am not very aware, like you folk are.

Did you know it squawks at you if cruise is on over 90?

 

Yah, but if you're going downhill (well Snoqualmie is more than a "hill" I suppose) you can get it to reach 100mph even at that setting.

 

My 85D is steady and solid as fast as I have driven it (110 or so). Feels like it's on rails.
However, there are a few sections of grooved pavement on I80 where it gets a bit squirrelly.