P85 (2013) floaty on high speeds

[Tato]

Hello all, I've upgraded my p85 (2013) battery to 100 kwh, which is not recommended by tesla. Same day I changed my wheels from 21" to 19", and putted on them Toyo proxes sport 245 45 r19 (summer). It was done in non official Tesla service center, as long as we don't have tesla official service centers in country.

Now I have huge increase in range, but floaty feel on high speeds . Have you had same experience? What could be fixed to make comfortable high speed driving?

I thought:
1. may be adding spacers could fix it?
2. Tyres pressure are set to 42 psi (290 kpa). Should I make It 45 psi?

 

[Tato]

And I have changed wheel configuration to match newly installed wheels

 

[GSP]

If the dampers (aka "shock absorbers") are 11 year old originals, they probably are worn out. The additional mass and worn dampers should both contribute to a floaty feel. I would try replacing with new dampers for a P100D, or aftermarket ones. Replacing the springs and giving all of the other suspension parts a good inspection would also be a good idea. Worn rubber bushings are another likely suspect.

Good Luck,

GSP