Twitchy steering at freeway speeds.

I usually avoid writing "me too" replies, not just in this forum, but in any online discussion forum.

But I'm going to make an exception here, because I too am watching this topic with special interest. The main reason I participate in PriusChat is so that I'll be able to decide with what to replace my slowly dying 1994 Camry. So far, the Prius is my first choice. But any serious safety problem such as this, even if "relatively rare", would give me a reason to reconsider.

 

I think it's a pretty well-established idea that new tires will do the trick, though, so if you're willing to make that investment, it's one to consider...

 

And to be honest with you, I think that 1800 complaints are suspect because the gentleman talked about his steering mechanism and the power steering. I think he had a pre-2004 car but didn't say so. 95% of our memebers have the 2004 but the more I think about what he said the more I think he didn't have a 2004 because the problem and solution fit the pre-2004 perfectly. I don't know what the number are, but I've met several others locally, one that sold his car at 1600 miles rather than go through what I have.

At this point Toyota is either slow to answer my 2nd (and 3rd) complaints or they're ignoring me. Either way, I've played their alignment game, had it checked by 3 other shops, etc. IT IS NOT ALIGNMENT with my car, period. I've even spent $100 to get the camber matched on the front, even though it probably would not cause this. So my attention is on the tires. Maybe I have a bad one. At this point I don't have anyway to tell and no one but my own experience with cars and tires to guide me. And my years as a motorcycle mechanic, mechanical engineer, car buff, etc tell me that at least my particular car is not right...period. It is not me or how I drive it. So it comes down to two choices, sell it or try to fix it. I love the car so I'm going to try to fix it. And the tires, about the lowest rated ones (34 out of 39 on Tirerack) you could put on this car, are the target of my attention. We'll know soon for me as I'm awaiting a call that my tires came in and I'll let everyone know. There could be a Salsa Red #9 for sale soon or I'll be one happy owner again.

As for Toyota, I've been the most polite and curtious customer with this problem. I've treated all the Toyota Reps with the utmost respect and dignity. All I got in return is a quick 10 min road test from a factory rep that was late in the first place and didn't have the common curtosity to talk with me after pronouncing my car normal. He just left me hanging like a fool, waiting in the waiting area for over 2 hours. So if I've kicked this up a notch and feel just a little bit burned by Toyotas lack of response, I hope some of you understand. Maybe, in retrospect, I should have been obnoxious and screamed that I was going to sue them or something like that. And believe me they made me feel like doing that. But it's just not how I treat other people. So I'm left to my own solution, which I hope will pan out today. Thanks to all of you that have been helpful. Those of you that don't have this problem, I do enevy you. But neither the Toyota rep, nor your good experiences with YOUR car, make my car handle any different. Saying it's so doesn't make it so.

 

Too Much Chatter over Twitchiness!

I just got on this forum and saw all the chat about twitchiness at high speed and in turbulence. I own a shop (on the side) and do a lot of work on rice rockets. I have had the same experience with my own 04, a little jittery at high speed. The way I fixed it was to replace the wheels with 16in rims and slightly wider, but lower profile tires so the speedo and ABS does not mind, nor does my mileage. This did it - and running a slightly higher psi on the tire (~40) to compensate for the lower profile. I did this replacement because I had experimented with the toe and camber (to the extent possible), and found that taking a bit of the toe in out was helpful, but not completely resolving the issue.

Now - the car is tall, it is broad, and at high speed, with a small footprint tire, it is going to act like a bicycle. Those of you who have replaced tires and found improvements have gotten it because you have a higher sidewall compliance tire, with slightly higher rolling resistance. Remember - stiff is better when it comes to mileage, but twitchy when it comes to handling. It is not a defect in the car - it is simply a matter of getting used to how the car handles and compensating.

If you have owned a rice rocket before, take a moment and realize that your weight distribution, hp, and aerodynamic profile were DRAMATICALLY different! This is not a sports car, will not handle at speed like one, and when you improve high speed handling, you will are giving up something else - like gas mileage. The Prius does not handle sideloads very well because of it's profile, so if you want a better handling car at 70+mph, then go with wider tires, bigger rims, and have your local alignment shop go with near zero toe-in, and a min amount of neg camber in the front, zero/zero in the rear.

Good luck to all - the Prius is a great car when you understand it is a slippery little eel - connected to the road with bicycle tires that ride very firmly......you can change that as you wish, or you can leave it alone and adjust your driving habits. Personally, I don't spend a lot of time next to 18wheelers with any car - too much stone damage and even my SUV gets tossed around like a bean bag. I am also a pilot, so understanding the turbulence at the front and the rear of these or any big rigs is probably why my expectations are less than perhaps some others. The more you stick up into this dirty air, the worse off you are. There is no slip streaming involved - that only works on cars of similar design and shape and when you drive within a foot or two of the pulling cars bumper. Good luck on that one.

Ciao yall!
Highest tank = 52mpg, avg 4000 miles = 46.8mpg

 

Good post Ginostef and good points. I just got back from a drive with my new Hydroedge 195H60X15 tires. I was going to explain exactly what you have already explained so perfectly. It's not a sports car, not a RSX like my wife has and we (I) should not expect it to be. With the new tires I think it's about 80% of where I would prefer it to be. And much much better and has stopped it sudden darting without warning like it was doing with the std tires.

No it does't "track" like other higher performance cars but it's very, very good now compared to before. I don't see much reduction if any in the mpg on my 22 mi quick test and I'll be looking at that in the future but right away on the first corner I took I could tell it was a big improvement. I'm so glad I went with the 195's too.

I have .05 deg toe-in at the front and -.5 deg camber for both fronts (had the right lowered to match the left). Both sides are essecially equal now. The camber at the back is -.9 deg left and -1.3 deg right. Do you think it's worthwhile to have this changed?

 

Ginostef's Twitchiness Fix!

Ginostef. Thanks for your detailed response to this issue. I was wondering if you could share the type, brand and size of tires and rims you replaced the stock equipment with?

And I understand that 16" rims are standard in Europe. Does anyone know how or where to get Prius 16" rims?

 

Hi Fred,

I'm so glad the new tires are giving you some satisfaction! I know you've had your "wandering" problem for some time, so I'm sure you are much relieved that you've found a good solution.

BTW was that you who parked next to me for pictures after the Prius meeting last week? I fear I was remiss in not introducing myself to more people--especially someone who had the good taste to choose a red car!!! Since so many of us read these message groups, maybe we should introduce ourselves by our screen names (i.e. " I'm FredWB with the wandering problem," or " I'm McBrunnhilde who got her car in Merced.") I hope we have name tags for the next meeting!

(edited 'cause I can't even spell my own name!!!)

 

Well this has to be a good feeling for you! you fought this hard and long so a victory is well earned. You should do a "recommended tire in the Data Base so other's don't have to work thru all the post made on this subject. Also a email to John might be in order so he can also include it in his data base. Please post the pressures your using and the F/R differential also. You gotta be smileing at this point. Ya Fred!

 

I'm going to recheck again when the tires cool down but I told them to put in42/40. Based on how they felt, I'd say they're around there. The car didn't feel as compliant right away. Almost like I put on stiffer springs, which considering the tires do have a spring component if you were to do a "free body diagram", something us engineer geeks tend to do on napkins for uninterested guests at lunch.

Yes I'm pretty happy with it Frank but I still can't quite understand how others don't find the handling kind of squirrely. The question will still remain unanswered, is it my high expectations about how even a basic car should behave, others lower expectations, bad roads here in San Diego, just something about my car, or WHAT? Whatever it is, I just want to go drive the car some more!

I'm going to drive it up to Elsinore again just to compare the mileage. The computer said I had around 50 mpg round trip on the old tires even with the side winds.

mcbrunnhilde, yes that was me, the wandering owner, with the Salsa Red #9.

 

OK, from this point on lets post, data about our tire replacements only. I'm going to wait until I've gone through at least one tank before I do. Maybe something like:

Tire size
Tire brand
Tire model
Miles at replacement
gas mileage before/miles
gas mileage after/miles
Short explanation about why you replaced them
Results with new tires.


Anything to add or change?