Instability at hwy speeds

I've not noticed this on my '07 or my '10. Stability has been perfect. Check your tire pressure. If there is a problem, an additional 3 psi can work wonders.

 

They do sometimes need alignments when new, and the high narrow profile makes them relatively squirrelly. After a month you'll probably be used to it and no longer notice.

 

Having owned my Prius going on 7 years (time sure flies) I noticed this too when I first got the car. To remedy it I did the following:
1- Changed to a better tire and actually a little wider
2- Make sure the tire pressures are correct and FWIW I do believe that the additional few pounds of pressure in the front vs. rear (as recommended) does hep stability.

Windy conditions definitely exacerbate the car's tendency to be a tad squirelly. Lastly as a few others have mentioned, you definitely get used to it.

 

You might need an alignment; mine was out of alignment on delivery. Pay particular attention to the rear toe settings - that is what gave my car a weird feeling at freeway speeds.

 

Sounds out of alignment to me too. There is a motorway/highway that I regularly use that is very high and exposed and notorious to side winds (the truckers lover it!) and the Prius does hold itself very well. Perhaps not as great as a sporty BMW would but certainly no worse than any similar car in its class.

Check your tyre pressures and alignment and if they're ok then hopefully problem solved.

 

I agree about getting the alignment checked. It also leads to abnormal tire wear and even though you have 3/36000 mile warranty, no one needs the grief. The only thing I would add is the electronic steering assist tends to take out 'road feel'. The earlier Prius seemed almost neutral in steering stability.

Bob Wilson

 

I have a gen 2 that when new was terrible on the highway without wind, front upper strut bar,under-body stiffening plate, hydroedge tires and 22mm rear sway bar made it drivable, the gen 3 as I understand it comes from the factory with an improved suspension, it does sound like alignment, and, or if you haven't upgraded your tires yet you might think about doing so.(highr air pressure also)

 

Not an unfair comparison at all, I drove a 3 Series for 2 years prior to buying this Prius. I did not have an M3 but my 330i did have the sport suspension package. I find the Prius I have now is just as stable, even in a strong wind, as my BMW was. Of course when it come to cornering ability and brakes the BMW wins hands down, just as the Prius wins for fuel economy.

I also owned a 2005 Prius which had real stability problems especially in the wind. It was so bad I could change lanes without moving the steering wheel! Turned out to be alignment, in my case it was because the car had been damaged in shipment either on the ship or the truck to the dealer. After I finally managed to get it fixed it was as good as any other Prius of that vintage but never as good as my Gen3 is.

My recommendation is get it aligned. It should be covered under warranty for the first year, just tell them you have had the problem since the car was new.

 

Well....I've never had a BMW, so can't compare...BUT I still have my gen. II Prius (05 135000 mi) & my gen. III Prius (10) is MORE relaxing to drive on the freeway than the gen. II ever was...FWIW

 

I can only compare to a 2003 Honda CRV and a 1999 Honda Valkyrie Interstate (motorcycle). The Prius handles better in high winds than either of my other two vehicles, and it is not as noisy.

 

I don't see it mentioned by others, but your BMW likely has a variable steering ratio (slow near the center, quicker as you turn the wheel more) so to some extent the wander at higher speeds was tuned out by your hand movement and by the slower ratio. The Prius ratio is not variable so a little wheel movement produces potentially more action than the BMW when steering straight. Not to say that the Prius will ever equal the BMW but if you concentrate on slower wheel movement at straight line speed I think you'll feel an improvement. My Lexus IS exhibits the same comparison.

 

My Prius is a little squirrely in the wind, but since my other car is an 01 Chevy Blazer, I'm used to it. I didn't even think about it for several months until a long trip across the Great Plains. Even then it was like, "oh, this feels like my Blazer."

 

Hello,

Just wondering if the alignment took care of the instability you were seeing or if you had to get anything else done.

I just became a proud owner of a used 2010 III (Solar) yesterday and it's truly an awesome car except for the instability I noticed while driving the 240 miles back home on the highway. The steering wheel needed input every 4-5 seconds to keep the vehicle straight.

Thanks.

 

Mine experienced instability at speeds +70MPH. I felt like the car would float and was a bit squirley.

I had an alginment done and the uneasy feeling of driving +70MPH was gone. The car was slightly out of spec and when I left it felt great.

My purpose of getting an alignment done wasn't to fix the high speed stability problem though. I had to get a rear tire replaced after hitting a pot hole and decided to get an alignment done just incase anything was knocked out of spec.

 

I've come to the conclusion that the Prius, given it's shape, is not going to be as stable at speed as other comparable autos. There is a price to be paid for great fuel economy, but it's not a deal breaker for me.

-Brad

 

I have the exact same experience on my 2010. I have had it aligned and upgraded the tires and still have the "wander" effect. I increased the recommended tire pressure by about 1 psi. Have you solved your problem?

 

The M3 is about 700 lbs heavier than the Prius, so it may also be that when you are feeling instability, you are over correcting based on the response you expect from your previous (very nice) ride.