Prius Handling Problems at Highway Speeds

<div class='quotetop'>QUOTE(ARiddle @ Apr 6 2006, 12:05 AM) [snapback]235696[/snapback]</div>

Well, my Volvo SUV gets only 18 mpg. Is it an issue I should report to Volvo? NO, it's just the nature of the car.

For the Prius, it is a very light car. Compared to all the other cars you listed, the Prius is a good 1000 pounds lighter than most of them. That make a HUGE difference. The Prius is much different from any of those you listed, and a direct comparison just doesn't work.

Why would I spend $160 to "fix the problem?" I wouldn't. I'm actually spending much more, and will probably end up being around $3000-4000. But am I really trying to fix a "problem?" No. Every car has it's faults (or trade-offs if you prefer), and there are often aftermarket manufacturers who make parts to help mimimize or eliminate those faults. They are not necessarily problems though. I am just taking the Prius's weak point and improve on it. You know, a Dodge Viper will also follow the grooves in pavement due to it's suspension setup and extra wide tires. Problem? No, it's just how a Viper drives.

As for the steering being vague, mine is not any more. The lower suspensin brace and strut bar fixed that. But does it feel like a BMW or a Lotus? No way, and I'd be a fool to try to make it so. But it's much better.

Speaking of Lotus, I just test drove an Elise a short while ago. If I tried to drive my daily 130 miles of commuting in it my nice person would end up bruised within a very short while (of course I'll probably do it anyway ). The ride is exceptionally firm to the point that you'll make your dentist very rich replacing the fillings that get shaken out. Is it a problem? Absolutely not! The car handles like nothing else. It's just a function of how the car drives. It also follows grooves like the Prius does. It's a trade off. It's what it is.

The stability in crosswinds is another issue. I think it's realted to the frontal aerodynamics of the car. I imagine there is some level of trade off with regards to side forces when you minimize frontal forces. Think of a paddle. If you turn it legthwise, it cuts through the watter with no resistance. But if you turn it as you would to actually paddle the boat and you get lots of resistance. Perhaps the Prius is similar. Fromt he front the air passes over very efficiently, but from the side it's not so efficient. But then you must consider the fact that cars don't normally travel sideways. Yes it gets buffeted in crosswinds, but it's not dangerous (unless, perhaps, you're an incompetent driver).


Just enjoy your Prius for what it is. Will it ride like your old Mercedes? Of course not, but your Mercedes never got mileage like your Prius will.

 

Yes, I agree that there is more of a "problem" with wind then with the grooves. If you think about it, you want a car to follow the road if it is to handle well. If it just "skipped" over those grooves, I would be concerned that it may not go the direction I wanted it to in a hairy situation. Some cars, like Mercedes, BMW etc, do a better job of concealing the tracking through the use of expensive dampening systems. However, in some cases you loose a lot of road feel that way.

Heavy SUV's "plow" their way through the grooves with their massive weight and larger tires. However, try to make a quick turn, and roll over city! They sacrifice a smooth forward ride for less handling capabilities.

Let's face it too, those grooves are massive. We are not talking little lines. Some of these are inches wide, maybe filled with that black goo, maybe not. The Prius is light weight, with skinny tires. Who is going to win?

As far as the wind, I agree with those above. You are driving a super aerodynamic car, designed to maximize MPG by minimizing its forward profile. Any significant cross wind is going to effect the car and get "caught" in the Prius side profile. Some of those braces probably do help the car from twisting, but they also add weight.

We all get caught up in the fact that these cars were fairly expensive. However, we paid for the Hybrid system, and got a small compact car, with some cool bells and whistles to boot.

The Honda may not have these issues (although my 2001 Accord used to move on those grooves too!), but from what I read, the MPG numbers, are much farther from the sticker then many of us have done on the Prius. They are also smaller cargo wise, and lets face it, very vanilla.

The Prius is great at maximizing MPG, and may just be fair-good at everything else (comfort, handling, etc.)
But for me it is still a blast to drive!

 

<div class='quotetop'>QUOTE(ARiddle @ Apr 5 2006, 09:05 PM) [snapback]235696[/snapback]</div>

All my cars have been modded for handling - and the Prius is just as a standard family car for it's weight should feel. And the handling isn't that bad at all, I don't feel unsafe til I get around 90 and then I need to make a turn. Around 100+ I have to make it wayyyyy wide. I'm a total idiot, I know. But I've gotten wider tires and I aim to drop the car a good inch or so. That should help. A lower center of gravity can make a car more responsive, especially such a tall one as the Prius.

 

Most any light weight and tall car will have trouble with wind. As for grooves, they tend to bother any car with narrow tires, and also cars with different front and rear wheel spacing. Prius is way better on grooves than some other cars I've had with the wheel spacing issue.

The steering ratio and the electric steering make the car more touchy or sensitive which can take a bit of getting used to.

 

I drive an '04. From the very beginning I noticed, and was not especially happy with, the handling in strong cross-winds. In North Dakota (where I lived until very recently) it is almost always very windy, and the freeway speed limit is 75. My old '89 Civic did much better on the freeway than the Prius.

There was a lot of discussion about this here on Prius Chat at the time. I do not believe that Toyota is unaware of this, though some individual dealers may be.

I can imagine that on grooved roads it would be worse. Here in Spokane the freeway is so rough that I avoid it. It can't be good for the car to drive on such a bumpy freeway, and I get better mileage on the surface roads.

 

<div class='quotetop'>QUOTE(coolfire74 @ Apr 5 2006, 05:28 PM) [snapback]235580[/snapback]</div>

Same here. I find myself glancing down at the speedo only to discover I'm at 75, not 65. It's not like my 1990 Ford Probe, but it's fine for me.

 

I think we're beating the topic to death considering:

- you haven't had the car aligned
- you haven't asked for toe-in
- you haven't installed the BT brace yet

I know you have these events scheduled. Please update this topic (and your other topic thread) when you have had a chance to try it with the standard fixes applied.

 

I don't understand what you guys are all talking about, I was driving in extrmely high cross winds (Approximately 45-60 MPH) at 80+ (And I do mean plus) MPH from Utah to Vegas and had absolutley no problem controling the vehicle, I have no problems in So. Cal. either, I just don't understand what everyone is refering to. I suppose it's possible that modifications were made to my vehicle before I got it, as it was used, but I don't understand what the handling problems are. I also have been driving the carpool lane on the 405 and have absolutely no problems, I just don't understand what this is all about.

 

I have purchased three new Toyotas (four including the Prius I am waiting for) - one Corolla and two Camrys. All three were out of alignment when they arrived at the dealership. I ruined the tires on the first one before I realized the problem. After that, I always have them aligned before I pick them up.

All of my Toyotas have also been blown around on the freeway in the wind (unlike my Hondas that seem very strudy).

 

<div class='quotetop'>QUOTE(cmwade77 @ Apr 6 2006, 10:24 AM) [snapback]235860[/snapback]</div>

It seems that at least some of whatever handling problems there were, were remedied in the 2006 model. I am puzzled by some of the wind and groove comments, since it almost seems like they refer to a different car. Maybe I just haven't been in a really windy area.

Currently my other cars are both SUVs, one Japanese and one European, and one is just over 5,500 lbs. LA roads are some of the worst-maintained ones in the civilized world (don't start me on that,) but I don't notice the Prius dancing much worse than others.

I still think, if ARiddle's car is a 2006 (as it appears,) that you should ask your dealer to test-drive another Prius on the same road and see if it makes a difference.

 

I have absolutely no problems with the handling of my Prius. No mods, stock tires. I drive anywhere from 60s to 80+. Many times I don't even realize how fast I am going. Some roads definitely have an effect sound and handling but no more so than with any other car/truck.

 

<div class='quotetop'>QUOTE(Black2006 @ Apr 6 2006, 10:56 AM) [snapback]235878[/snapback]</div>

I have a 2004 and have no problems, as a matter of fact, handles better than any other car I have had on the same roads, this includes a Pontiac Grand Prix, Nissan Sentra, Chevrolet Malibu and Dodge Dynasty.

 

I spend over 500 miles a week on LA's "groovy" freeways in my '06. I have the standard Goodyears and have never experienced a problem with tracking the grooves. I do get blown around on windy days, and passing big rigs. When the grooves first came in the consensus was to find tires with without "linear" tread patterns, but more random criss cross patterns, not easy to find with regular passenger tires. Anyway, I've had no issues at all with the grooves to date. My car has over 5000 miles on it. Maybe it has to do with tread depth and/or design. It may be worth a call to Goodyear customer service, or someplace like Tire Rack to see what tires they recommend. I don't think it is a special problem for the Prius, or everyone would be complaining. My guess is tread design or possibly alignment. I have two other cars, an Outback on Michlein MXVs from Costco, and an Impreza on GY Eagles, no issues with grooves on them either. Also, try experimenting with higher pressures. I run the recommended 40F, 38R. No mpg gain to speak of, but improved handling and road feel. The BT brace is on order.

 

<div class='quotetop'>QUOTE(subarutoo @ Apr 6 2006, 12:14 PM) [snapback]235915[/snapback]</div>

On my '06 I ran for a few weeks at stock pressure, then upped it to about 40 psi to see if I could get better mpg. I noticed the car felt much more jittery on the freeway, so a few weeks later I lowered the pressure back to stock and it feels better again. I can't understand the logic that the higher PSI is going to make an already jittery car feel better. I bike a lot and while a higher PSI produces much less road resistance (i.e., a smaller contact patch, so I can go faster with less effort), I feel every little bump. With a lower PSI on my bike I get a much smoother ride.

I can't understand why this would not be the same for a car - and as I said - my personal Prius experience seems to confirm that a higher PSI is going to produce a much more jittery ride. Perhaps the sidewalls will be stiffer and it will corner better at a higher PSI, but on the freeway it seems to have less predictable steering and feels much more jittery to me.

I'm no expert, so if I'm off base here, can somebody please (gently) check my logic? In the meantime, try LOWERING your PSI and see if that helps.

 

I found this on a google search re: tire pressure. Like I said, I maintain lower PSI will help your problem...

re: bikes: http://www.bicyclesource.com/bike/modifyin...e-tactics.shtml
"Pressure Tactics

A simple change in tire pressure can have a profound impact on the performance of a bike. Rolling resistance, traction, reliability and the feel of the ride can be transformed by changing the pressure by as little as ten pounds per square inch.

Road tires should be inflated to the recommended pressure on the sidewall, which minimises rolling resistance and tire wear. If your favourite routes are rife with uneven pavement or cobblestones, or if you just can't get used to the jittery feel of a fully-inflated tire, then try ten to twenty psi lower. If you use much less pressure, you run the high risk of a flat from a bump pinching your tube. If you exceed the sidewall recommendation, your tire can separate from the rim as the wheel soaks in the heat from some heavy braking.

The rules for mountain bike tires are a much less strict. Despite the astonishingly vague pressure guidelines on fat tires, you should try a pressure near the middle of the range, about 40 psi, and try changes. A higher pressure will make your tire rock hard, and should only be used if you're too cheap to buy a real bike for road riding. For the trails, a lower pressure will feel soft and squirmy, and give you the impression of being pulled backwards by the rolling resistance. Low pressures do increase traction, but they also increase the odds of getting a flat. Low pressures also make cornering unpredictable and not fun."

re: Prius:
http://www.autoblog.com/2004/09/20/toyota-...g-garage-day-2/

"11. You might want to check the PSI in your tires. Toyota delivers the 04 Prius with about 44 PSI in the tires, but recommends 35psi front and 33psi rear. Some dealers will change it to 35/33psi some will not. I drove my Prius for about a month before I realized that I had 44psi in the tires. Once I lowered to the recommended pressure I noticed a real difference in the ride, especially on highways it didn't throw you around as much. Some people will tell you that you get better gas mileage if you set the pressure to 44/42psi or 42/40psi, there has been much debate about this between Prius owners. Personally, my gas mileage did not changed at all when I lowered my psi to the recommend settings. I have been getting between 51-53mpg per tank since I bought the car."

"17. I second Hank's comments regarding the effect of tire air pressure on ride comfort. My 2004 Prius was delivered with 50 psi in the tires. After about 2000 miles of rough jittery riding, I lowered the tires to 40 psi and was pretty happy. At 10,000 miles the dealer dropped the tires to 37 as a part of the oil change, so I stuck with it to see what happened. It now has a very supple ride, and the mileage is amazingly unaffected. I'm averaging 52mpg same as always, even with full time AC blasting this summer. "

 

By the way, the 2006 Civic Hybrid also feels slightly disconcerting at high speeds even on smooth pavement, though I fixed that by replacing the tires. Since you already changed the tires and still aren't satisfied, consider changing the alignment so the front wheels point slightly inwards; most cars do this by default at a very slight expense of fuel economy.

 

At first, I found that the VERY TIGHT steering linkage on the Prius was bothersome (no "slack" as in ordinary cars). Soon, I adjusted to this feature and now find ordinary car steering "loosey-goosey." I do find some very slight instability in strong crosswinds and in heavily grooved pavement, not much.

I believe the standard "0 toe-in" on the Prius is part of your objectionable highway instability and like the previous poster who had his toe-in adjusted suggests that it could be helpful for you. More toe-in would tend to increase wear on your tires and reduce your MPG's, but probably worth the effort in your case.

 

<div class='quotetop'>QUOTE(ARiddle @ Apr 6 2006, 08:45 AM) [snapback]235816[/snapback]</div>

We drive the same road and I have never had an issue with this. Just keep both hands on the wheel I guess.