Prius Handling Problems at Highway Speeds

I've had my Prius for 10 days, and here's what I've been experiencing: The car does not want to drive in a straight line. When I'm driving down the highway - a smooth highway here in New Mexico - it will head off a bit toward one side. I'll correct, but instead of driving straight down the lane, it will head off toward the other side. I can't get it to drive in a straight line, and I'm constantly having to adjust to keep it in the lane, much more so than I have to do in my trusty old 4Runner. I haven't experienced the darting that some other posters mentioned. I thought there must be a slight alignment problem, but after reading this thread I'm wondering if my experience may not just be normal for a Prius. I'd appreciate any feedback on my experience.

BTW, I just discovered this site yesterday, and it's great! Very informative, intelligent posters, and some humor to boot. Thanks to the those responsible!

 

<div class='quotetop'>QUOTE(abqrichard @ Apr 7 2006, 07:21 PM) [snapback]236601[/snapback]</div>

What you describe is exactly how mine was acting before I had it aligned, I think it is actually how they are supposed to drive but I didn't like it.
Make sure you ask for toe-in, that will help hold the steering wheel at center.

 

Quick question about the alignment.....The hubby wants to know how the toe-in alignment and increased air pressure affect tire wear??? Thanks!!!!!!!!!!!!

 

Toe-in slightly increases tire wear (but I think its well worth it) while having more pressure usually reduces tire wear.

 

<div class='quotetop'>QUOTE(benighted @ Apr 7 2006, 10:46 PM) [snapback]236644[/snapback]</div>

Thanks for the info!!! It is appreciated as is all info gleaned from this site!!!

 

Thanks for the feedback, benighted. How did the toe-in effect your gas milage?

 

<div class='quotetop'>QUOTE(abqrichard @ Apr 7 2006, 09:25 PM) [snapback]236662[/snapback]</div>

No Problem. I didn't notice any effect on gas mileage.

 

<div class='quotetop'>QUOTE(ARiddle @ Apr 5 2006, 06:31 PM) [snapback]235547[/snapback]</div>

This issue has come up before and some “fixes†work better than others. I think you’re referring to highway “tracking†correct? How well the car holds a straight line on the highway?

First of all, it appears only a minority of +2004 Prius have this issue, and then in varying degrees. The car is narrow and tall, that probably doesn’t help matters.

Upon delivery mine was borderline, especially compared to my parents 2003 Buick LeSabre - at Trans Canada speeds one finger on the wheel is all you need. I’d have to describe my Prius as “twitchy.†I also had a 1993 Honda Prelude that was “twitchy.â€

Unlike your dealer, mine readily agreed there was a problem especially on roads damaged by heavy traffic (Grooves under each wheel due to overloaded transport trucks). They did a couple of complimentary alignments to factory spec and even put the car in their collision shop to confirm the unitbody wasn’t tweaked. It wasn’t.

The alignments helped reduce the twitchiness by about 50%, then I put on Michelin Harmony and the twitchiness was further reduced. I believe it was forum member 200Volts who suggested moving the little chin spoilers to the very front of the car.

I tried that and the problem completely went away. However, there is no way I could drive around here in winter with the chin spoilers sitting at the very front of the car, the first patch of frozen slush on the road and they’d be crushed. So for winter I moved them to the stock position.

When I put on my winter tires, I fully expected the problem to get much worse, as most winter tires have soft squishy treads and a lot of sidewall flex. The first winter I ran Dunlop Graspic DS-2 and they actually *improved* the highway tracking. Second winter I ran Yokohama Ice Guard winter tires, which had much better ice and snow traction over the Dunlops, and those things were squirmy at highway speeds.

I played around with the chin spoilers and if you move the inboard edge about 1.5cm towards the front of the car, you get almost the same improvement as moving them to the very front of the car. Plus I can then leave them alone all year round instead of moving them in preparation for winter.

My dealer is still very involved in this matter and still offers a complimentary adjustment every 6 months. They’ve also modified the toe settings and just beyond factory specification, the car tracks almost like my parents much heavier LeSabre. There is no effect on tire wear or fuel economy that I’ve noticed.

 

<div class='quotetop'>QUOTE(RichBoy @ Apr 6 2006, 09:53 PM) [snapback]236122[/snapback]</div>

Wow I'm gone 2 weeks where did this prick come from?

 

<div class='quotetop'>QUOTE(ARiddle @ Apr 9 2006, 07:43 PM) [snapback]237308[/snapback]</div>

Those tiny little spoilers in front of the front tires. They're very hard to notice unless you're looking for them.

 

<div class='quotetop'>QUOTE(jayman @ Apr 8 2006, 12:57 PM) [snapback]236799[/snapback]</div>

Most likely some jackass Prius driver trying to perpetuate the SUV drivers are jerks stereotype.

 

<div class='quotetop'>QUOTE(benighted @ Apr 7 2006, 08:46 PM) [snapback]236644[/snapback]</div>

No, increasing tire presure does not reduce tire wear - you'll cause the tire to ballon up if you use too much and the tire rides only on the middle. This is where people think it's reducing tire wear, the edges of the tire are not wearing out quickly because they're not touching the ground! If you look at the center of the tire, it's wearing too quickly.

Also, over-inflating a tire reduces traction, since you have less rubber on the ground. You'll get better mpg since you have less drag, but the issue of the car wandering would be increased, and stability, handling, and breaking ability would be decreasd. Go to a straight-line track and watch the 1/4 mile guys take air out of their tires for their drive wheels so they can acceletrate better and have better ability to keep their car straight.

Anyway, if anyone increases air in their tires beyond the tire's rating, get dirty and put your head on the ground, look at your tires dead on with some light behind it and make sure that your tire is flat where it's supposed to be, making good contact with the road. After an oil change, run your fingers over the tire and see if the sides feel newer than the middle.

Oh, and if you put too little in and the sidewalls of the tire are touching the ground, you'll cause the tire to at best will de-bead and suddenly deflate, or burst into itty-bity pieces. Having too little will reduce the ability to change direction smoothly.



<div class='quotetop'>QUOTE(DocVijay @ Apr 9 2006, 06:55 PM) [snapback]237338[/snapback]</div>

On the net, people who do that are called 'trolls'

 

Well, this morning I was driving across the Sunshine Skyway Bridge and there were very high gusts of wind, approaching 35 mph. I was thinking about how bad the Prius is in strong crosswinds, but hten I noticed that all the other cars were weaving back and forth because of the wind too. I think it may just be that the car is lighter, so we feel smaller gusts that bigger cars don't.

 

<div class='quotetop'>QUOTE(ARiddle @ Apr 10 2006, 10:55 AM) [snapback]237573[/snapback]</div>

Heh, heh. I've felt this anomaly at 55 mph and at 65mph. It has more to do with the road surface, slope, curve angle, and conditions than it does speed.

Thanks for the post. Looks like I'm going to have to take the car into the dealer for a check. I was hoping to wait until 5000 mi. but now I want to see if this is the root cause of the problem.

 

<div class='quotetop'>QUOTE(abqrichard @ Apr 7 2006, 07:21 PM) [snapback]236601[/snapback]</div>

Think pressure. Increase steering wheel pressure in the direction of the correction for deviations as opposed to consciously turning the sw. The steering is so tightly coupled that a perceptible sw movement can be an overcorrection when at speed.

After giving this suggestion to my wife, riding with her became (somewhat) less frustrating to me.

 

QUOTE(abqrichard @ Apr 7 2006, 07:21 PM)

. . .The car does not want to drive in a straight line. When I'm driving down the highway - a smooth highway here in New Mexico - it will head off a bit toward one side. I'll correct, but instead of driving straight down the lane, it will head off toward the other side. I can't get it to drive in a straight line, . . .

<div class='quotetop'>QUOTE(hschuck @ Apr 10 2006, 02:17 PM) [snapback]237691[/snapback]</div>

I agree with hschuck and it does take awhile to learn how to drive the Prius with its sensitve steering. Plus, installing a BT Stiffening Plate really does a nice job of increasing the stability of the vehicle. Especially in these high winds we've been having.

 

<div class='quotetop'>QUOTE(Vagabond @ Apr 10 2006, 03:16 AM) [snapback]237434[/snapback]</div>

I'm going to have to disagree there, kind of. If you run TOO MUCH pressure, it will baloon up but that is what MAX ratings are for. There shouldn't be a problem with uneven wear as long as you stay under MAX. I run mine 42/40 and i still get slightly more wear on the outsides of the tires.


<div class='quotetop'>QUOTE(Vagabond @ Apr 10 2006, 03:16 AM) [snapback]237434[/snapback]</div>

Taking air out of tires can increase traction if you need to. I've been in many sitiations here driving on the beach and the sand gets soft where if you lose momentum, just run the tires on the drive wheels down to 10lbs then gently rock back and forth until you can get going again.

<div class='quotetop'>QUOTE(Vagabond @ Apr 10 2006, 03:16 AM) [snapback]237434[/snapback]</div>

Good advice.

 

When I gave the Prius to my wife, I warned her of the Prius' sensitivity with the steering.

When she started driving, she went.. what are you talking about. She said the Prius was way more stable than her old 1996 Camry.... which I have to agree.

So it really depends on where you come from. I drove the LX470 and s2000, so I could tell the difference (LX470 went bye bye for the Prius). But even the LX470 would be a nightmare with strong winds... just that the steering does not suck like the Prius.