Newbie feels "floating" sensation at high speeds

Did you check the air pressure in the tires? Low tire pressure can produce the feeling you experience. I used to drag race many,of my cars and I would usually drop the tire pressure to aid in traction. Sometimes I would leave the track and forget to air up the tires before hitting the freeway and the car felt very unstable and would sway from side to side due to the very flexible sidewalls on the tires. Airing the tires back up fixed the problem.

I have always felt the same sensation in my prius when the dealer or a tire shop dropped the tire pressure to stock levels (35psi approximately). Raising the pressure to 40psi or more makes the floating sensation go away or is much reduced. 17inch wheels with low profile tires pretty much cures it entirely.

 

Try higher tire pressure like F8L suggested, it helps.

The steering is kind of dead and doesn't give as much feedback as the steering systems in my other cars. That gives what I would call a disconnected feeling. I got used to that which is fortunate becasue there is no reasonable fix for that.

 

Took me about a month IIRC to get over it. Seems like I always was correcting it's path. I don't notice it at all and the funny thing is my wife has never mentioned it. Guess we are sensitive. ?

Welcome aboard by the way!

 

What tires are on your Prius? My winter tires (ContinentalExtremeContacts) give me that floating sensation at high speed. Much more so than my summer (Bridgestone Ecopia 20) tires do.

 

What is your previous car?
If you have a German car before, don't expect the Prius will give you the feel of precise tracking on the road because the Prius has a cheapo front and rear suspension system.

 

What german car in Prius's size category has a better suspension? I know they have much complicated construction, but I don't feel it better.

 

The Prius sits higher than most cars to make room for the battery. Several of my passengers have said it feels high(and that was even after the car lowering!). So that contributes to the floating feeling.

I don't think anything is wrong with your vehicle. It's a feeling we all get used to. However, I think you have a great excuse to lower your car!!

 

I know what you mean. My Prius reminded me of my GF's old Avensis which had very floaty steering. You will get used to it!

 

Hi EDP,

Many of us run tire pressure at 42/40 (Front/Rear) psi. This helps with tire wear, but also with that floating feeling. The ride will be rougher around town, however. But, you will get better fuel economy with this too.

If that does not help, take it in for an alignment. Its my understanding, if the car is out of alignment, the alignment within one year of purchase is free. This kinda of floating feeling is usually related to the rear suspension being out somehow. If it is, do not let them tell you its not adjustable. You may need to take it to a private shop and have shims made to align the rear however.

 

I've been inflating mine to 40 psi all the way around, the car just hndles better period. Yes it rides rougher but at least it feels more connected.
Welcome aboard!

 

Another factor not mentioned is the Prius fixed steering ratio, while many cars have variable ratio steering. Variable ratio has a slower response in straight-ahead, and more rapid response to steering inputs in turning and parking. As a result, small corrections at higher speeds as you keep the car going straight are not as noticeable with variable ratio, but are noticeable in fixed ratio unless you spend some time practicing to minimize corrections. "Float" usually means instability in the suspension, but is it possible you're feeling this more pronounced fixed ratio left-right correction at higher speeds until you've had more miles in the Prius? Just a suggestion.

Jim

 

My '11 sometimes gets a feeling of floatiness similar to a slight crosswind pushing on it, and seems to do it after accelerating around 60 - 65, but then it goes away. Kind of strange.

 

The rear shims are off the shelf aftermarket parts.:rockon:

 

I would inflate front to 44 and rear to 42 - max sidewall pressure on front and 2 less in the rear. This will also slightly improve mileage and give you longer tire life. Toyota door jam numbers make my car feel "squishy to me" and I also do this with my other two cars.

 

But the prius electric power steering adjusts the assistance according to speed, there is less assistance at speed so it shouldn't feel "floaty".
My steering felt a little vague during the first 500 miles or so on motorways, I put it down to the tyres bedding in.

 

It could the electric power steering. It literally takes me about 3 month to get used to it driving on high way.

 

It's because of a poor implementation of electric power steering, not electric power steering in general.