Twitchy steering at freeway speeds.

The tires in my sig cured the problem. They also improved ride, handling, noise, wet and dry grip, stopping distance, acceleration (I think, with the slightly smaller rolling radius), and tramlining (tendency to follow road grooves). The tire dealer gave me a generous credit for the OEM tires for a net cost of $240 including M&B and replacement road hazard warranty. The car performs much more closely to what's experienced in other F/F sports sedans while becoming more relaxing to drive at speed.

The downside was that fuel economy took a hit. At first I thought by maybe 10%, but couldn't tell for certain because of cold ambients. I'm still not sure because my car isn't broken in yet, but even if it's a 15% hit it's worth it IMHO.

 

I have also noted the twitching you refer to. Maybe it's caused by side winds pressing onto the large surface of a tall car weighing under 3000 pounds.

 

There have been posts over the last 6 months saying that the 2 psi difference front to rear is important for this reason. Some also advocate a higher setting than mfg spec. You might want to check your pressures.

 

I experienced this. Coming home form WV, we were on a curvey road in the mountains with lots of trucks. The car was very "squirley". I haven't been on those roads since the ride home from the dealer, and I haven't had the problem since.

 

Since I reduced the tire air pressure to "standard" the squirrley twitchy high speed ride disappeared. go with the recommended psi.
rn

 

Even though this thread has been silent for awhile I'd like to comment. I've complained about the twitchyness of my Prius for the last 5000 miles. I've had the alignment checked and adjusted or tweaked by the dealer 3 times. I had a very knowledgeable Prius owner drive mine on the freeway and at first it seemed OK to him, just a little more sensitive than his car. Be after a few miles and at a slightly higher speed he really noticed a difference which renewed my determination to get this thing fixed. It's not right and more importantly I'm really believing that it IS NOT LIKE all the other 2004 Prius out there. That's why some have implied that it can't be or emphatically say that THE Prius handles better than any car they've owned. We just can't be that far apart in our expectations and experience.

So I believe that something IS wrong with those few of us experiencing this. In fact I met another owner with this problem at our local Prius Club here in San Diego. So I urge you to contact your dealer if you have this problem. Get the alignment checked first and then if that doesn't work, have them elevate this to Toyota directly so we get some resolution. That's what I've done and Toyota is sending someone out next week. I'll keep everyone that's interested posted in this thread and hopefully we'll all be enjoying our cars more very soon. Oh and I think the description of the problem for me is that my car just appears to want to go in any direction so easily that road grooves, other cars and trucks passing and side winds cause me to have to apply a correction constantly to insure that goes somewhat straight. Or simply put, it doesn't TRACK well. It probably looks twitchy from the back.

If it was tires only (no doubt tires help for sure though) then all others would be having the same problems, unless the owner that changed his has some defect in his tires others do not have. If it was air pressure, then there would not be that many saying it handles better with MORE air pressure. If it was alignment, and if my dealer knows what they're doing (big assumption I know), then they would have fixed it by now. Whatever it is I'm going to try to get to the bottom of it one way or another. I have an expert trouble shooter/alignment/suspension expert waiting in the wings if Toyota fails.

 

Yes this made me quite upset too :mrgreen: , here they sell you a 25k car, and put tires of the lowest 1/32 percent Quality on the vehicle. Not even our friends at GM are that bold...

According to Tire Rack, there are 38 Tires that can be used on the Prius, and MR Goodyear has the impressive (negative) INtegrity ($51.00) rated at position 6 from the bottom. This is a slap in all prius owners face, aspecialy if you compare this to a tire that is only marginal $29.00 more expensive, the Michelin Harmony, which has none of the behaviors and problems that this pice of s.... tire from GoodYear exposes.
The Goodyear scored average of 4.2 while the Michelin socred 8.8.

I have contacted my Dealership too, and have learned that if you all, and I write an email to Toyota with the same topic, they will learn that they will have to do something about.

here is the link to there page:
http://toyota.custhelp.com/cgi-bin/toyota....fcGFnZT0x&p_li=
So lets flood them!

Ralph

 

Great tip on Toyota Customer Service. I just emailed them about the wandering at freeway speed and the gas gauge while I was at it. I'll let the group know if they get back to me and what they say.

Jeff

 

Wandering at 70mph +.... at higher speeds the aerodynamics of the car come into play...if your driving around heavy vehicles...like trucks. then you will feel even larger aero forces on the lightweight Prius. I would think this is normal and for folks downgrading from big SUVs...feeling the aero forces may be a new dimension in driving and not necessarily a defect in the vehicle.

It would be nice to see if changing to a different tire could make some handling improvements since the Goodyear Integritys are not noted as a great performance - handling tire.

Also tire pressure may also play a factor...if your running higher pressures in the front than rear...this could effect the aero response of the car much like an airfoil wing and cause the front end to float at high speeds???? An easy test is to try equal pressure in all four tires, then maybe 2psi lower in front than rear.

 

Well I had my day with my Toyota Prius Expert. I never saw him, didn't talk to him or my dealer's customer service rep that was coordinating this. And since they were all late, I waited 2 hrs in their waiting area, had my cell phone, and instructed the service writer to inform me when they arrived. They spent all of 10 minutes on the road and pronounced my car like all other Prius...normal!!!! What bothers me is I waiting patiently 2 weeks for this day, did not yell or rant or rave at anyone. When thinking out loud in front of my service writer later, I said I wonder what I'm going to do now because my car just is not right. His reply was "find another dealer"?

I have never, nor will I ever, own an SUV, just to set the record staight. This is the heaviest car I've ever owned. Most recent cars are 2003 RSX, 1990 CRX-SI, 1993 RX-7, 1986 CRX-SI, 1990 Nissan Truck, 1994 Integra, Fiat X1-9, etc. They all handled better going down the freeway than my Prius. The Rx-7 had an issue close to this which turned out to be tires and was cured with a differnent design/brand. But that's not implying that there's anything wrong with the Integrity tires. My wife's RSX is my current gold standard. It flat out tracks straight and true. And the mags panned it for a nervous front end in earlier years. It just instills confidence in spite of its harsh suspension and ligher weight than the Prius.

Yes, in varying degrees, you could feel the road grooves with these other cars. But nothing like this. But I do agree the faster you go, the more noticeable my Prius problem is. I personally don't go much beyond 65 these days in my effort to slow down and live. But it's a very noticeable problem for me even at that speed. My trip to Vegas was the most tiring one I've ever experienced with any car, truck or Van.

My SD Club friend, Tom Sprauge got a similar result at his dealer. They claimed it's the electronic steering that's doing it and that they're all alike in this respect. Although I don't buy that, anything is possible. I have about two more things to try before I give up and put my car up for sale. The first is an expert that has solved some tough car handling problems over the years, even before the manufacturer did. The other is a new set of tires. After that I'm ready to call it quits. I can't really drive the car long distances comfortably. My wife is actually scared to drive the Prius. Given the right conditions I can see brushing an adjacent car/truck/guard rail and hurting myself or someone else.

In short I don't it's me, it's my car. Beyond that I have ideas about what it could be but no real solutions yet. It's not tire pressure as I've tried them all. I'm back at 35/33 because that for me and my car does appear to be slightly better.

 

As much as I'd to agree and blame corporate Toyote for shortchanging us on the tires, just keep in mind the countless discussions on what Toyota's profit margin is and how long you've waited (or others are currently waiting) for the Prius.

I've owned and driven anything from 5000lb SUVs to 385 lb race bikes. If you think SUVs can behave any differently flying by semi trucks at 70+MPH, you must be in Prius heaven. On the motorcycle, riding by any bus, truck, or SUV, you WILL get pushed in both directions. Immediately behind the driver door is a vacume area and conversely a wall of air right before the driver area. Thus, you will first be sucked in towards the other car and then pushed away. In addition, all roads are pitched away from the center median for drainage purposes. On top of that, the grooves in the road wear and enlarge.

It's just a fact of driving the Prius. Slow down, stop complaining, or buy a heavier vehicle...perhaps the Highlander Hybrid?

 

Sorry to disagree, but for me and my particular car is has absolutely nothing to do with weight. This IS the heaviest car I've ever owned, period. And another Prius owner, after driving it, agrees it DOES NOT behave like his. His comment was that he thought it would tire him out with all the attention it needs to keep it in the lane. It's more than feeling the grooves or feeling a side wind. The car will veer unexpectedly and disproportionately when an outside force like cross wind etc is encountered. It's like the car is completely neutral and can go in any direction it's push quite suddenly almost quicker than you can react to it. And because of this the correction never seems to be quite right. I think that's what I mean when I say my car does not track very well. I also think, while not a fault, the soft suspension, high side area, narrow track, relatively long wheelbase, and narrow tires all exaggerate the problem some of us are experiencing.

To close I just want to say that I'm not implying that ALL Prius do this. Just a few it seems. My fellow engineer that drove mine confirmed that for me. So please try not to get upset with those of us having problems. Be thankful that you're not. These are very real issues and I just hope that one of us doesn't have a disasterous accident before we can get Toyota to stop saying that "they have never heard this complaint" and start some serious investigation into a solution. I would not be trying to fix mine if I didn't love the overall car and concept that it represents.

 

It's perfectly okay to disagree as I believe that is the foundation this country was built on. If I came across as "angry", I do need to apologize. It is sometimes disheartening to hear about the complaints and anti-SUV sentiments in these forums. Considering the millions of dollars and countless hours of engineering that went into a revolutionary car like the Prius, it's sickening to hear about how people are only getting 45 MPG (45!!) instead of 60, tread wear, and prices people are paying. I got my $300 check from Toyota yesterday and gee whiz, I don't hear Toyota complaining about the $300 x number of Prius amount of money they volunteered to return to the Prius owners......especially after they purchased the vehicles already!

All in all, hopefully, Toyota will be able to address the difficulties you are experiencing. But with a 7.28" wide tire (with contact area significantly less), I'm not holding my breath in hopes of eliminating drift.....and yes, I do experience it more than I'm confortable with also.

 

I didn't mean to bash SUV's. After all there are some people that really do need them. When you look at the size of baby strollers you know that a Prius just would not cut it if you had a couple small kids. And like you, I'm realistic about the gas mileage. I have to work to get 50 with all the traffic and canyons and the it's amazing the car can do that all things considered. And I'm not moving to Florida just to get 55 mpg!

But even the same width tires can track differently. My RX-7 taught me that. The new Yokohamas on the RX-7 did just what the Prius is doing and the Potenzas I put on were like night and day. I just don't want to jump on the tire solution until I've exhausted all other avenues. But it may prove to be the only thing that helps at this point. I just don't want to give up my hard earned 50 mpg either with a tire change. Oh well, can't have it all I guess.

 

Actually, my double strollers fit in the Prius along with two diaper bags and a bunch of toys. The SUV served its purpose of getting me on job sites that were not paved. Although sad to see it go, I'll be laughing all the way to the gas station. 50 MPG vs 9 MPG IS night and day!

As with you, I'm not willing to sacrifice gas milage for performance or comfort. Let's call it roughing it Prius style!

If you find a better compromise, please drop me an "e!" Good luck!

 

I keep reading all these complaints and wonder about the European version. The European version seems tuned for higher performance with larger wheels and 4 wheel disks. Anyone across the pond care to chime in? My opinion is that there is too much boost in the power steering. I'm surprised that Toyota did not make the boost speed sensitive.

 

Yes I'm starting to wonder the same thing. I think I also read about a stiffer suspension too. So that combined with slight wider tires (I think 195's??) might just make the car track a little bit better. I also think someone said they're using Michlins??? The suspension is not all that bad but just a liitle bit soft and bouncy for my tastes. The other extreme is my wife's RSX Acura. Even the std 160 hp version has a way too stiff suspension. I'd take the Prius any day over that. Something right in between would be ideal....again...only in my opinion.