Just received my new Prius but have a problem

your welcome, good luck, & nice to met ya.
let me know what happens.
Good night !

 

Wind? You didn't originally mention wind. The car has a high side profile, so crosswinds will toss it around. And we have had high winds this past month.

 

I would say a combination of the tall, narrow profile and low Cd really make the car sensitive to strong crosswind. It's not like the car has a trim tab or autopilot to compensate for it either.

When I directly compare the highway tracking of my parents 2003 Buick LeSabre to my Prius, there really is no comparison. I can drive that big Buick all day long with one finger on the wheel and it tracks perfectly.

With my Prius, at delivery the highway tracking was downright scary. They did a courtesy adjustment and that made it a lot better, but still not perfect. Next to go were the Goodyear Integrity tires for Michelin Harmony, and that seemed to help a lot too.

But the Prius still doesn't track like my parents LeSabre, which also has Michelin Harmony tires on it. You'd think a big floaty land barge like that would be all over the road, but it actually feels quite tight for highway speeds.

As far as the Goodyear Integrity it's nothing more than a low-bidder OEM tire. I completely agree with Kyle on this point. If it was so s*** hot, why is it one of the cheapest tires in that size range?

Go to Tire Rack and look at the survey comments for that tire. For the most part, people are unimpressed by the tire, no matter what car they drive.

 

Brian:

None whatsoever.

Even running the Dunlop Graspic DS-2 winter tires, on the highway at temps slightly above freezing they only hit me 3 MPG. That surprised me when you consider their sticky winter tread pattern. If you look at their winter tread pattern, you'd be surprised too.

The Harmony tires are slightly quieter at highway speeds. No difference at city speeds.

Yeah, that would change the Aspect Ratio. I'm not sure if going from 185mm to 195mm would make a huge difference though: 1 cm at best. I could see going from 185 to 225 making a difference.

Some folks have tried that by either relocating the little chin spoilers in front of each front tire, or by fashioning their own spoiler. Results appear good. I'm willing to try it and the local speed shops report they could easily make up something for me for under $200.

The only catch is that it would have to come off in winter, or I could end up getting stuck too easily.

Jay

 

I've never understood this issue. I drove 1700+ miles fully loaded down at 76 and 81 mph and I have driven in the 90 mph range for shorter distances and have never experienced this. It's a two finger car.

 

Agreed. Must be one o' them subjective idiosyncrasy things.

 

I strongly believe that the car has trained me. When I first bought it in Dec 2003, I felt that it wandered more than I was used to and caught me by surprise a few times causing a bit of a fright. My commute is 40 miles on interstate and I no longer notice any wandering unless there are substantial cross winds.

 

Ray:

If you don't have this issue, then congratulations. It does appear some Prius owners do have a highway tracking problem, in the case of FredWB serious enough to make them consider getting rid of the car.

Upon delivery, my Prius was a handful at highway speeds. The dealer gave an alignment after they found out the camber and toe were *way* off. That helped a lot, but still not what I was used to or expected.

Before my winter tires arrived last December, I drove out a few times to the hobby farm on the Michelin Harmony "all-season" tires. Once on the way back after a major blizzard, I had a white-knuckle drive for over 2 hours.

As FredWB had posted, it felt as if the car was hinged in the middle. True the roads were icy and drifted over with snow, but other cars and even empty pickup trucks didn't appear to be having too much difficulty.

At speeds over 70 km/h (45 MPH) the back end entered into a regular pendulum-like motion with a period of around 2 secs. It didn't matter if I took my hands off the wheel - to see if I was somehow contributing to this - the motion continued. A few times it got bad enough for the chime and the VSC icon to flash.

Slowing down to 60 km/h the car felt like any other car. At that point I was being passed by everything is sight. Not a pleasant return trip.

When my Dunlop Graspic DS-2 tires finally arrived, I immediately put them on to at least have some traction at icy intersections. I found out that the pendulum-like motion was still there but only at 100 km/h or faster. I don't mind slowing down to 80 km/h under icy conditions.

Some folks have commented on the Goodyear Integrity having too much sidewall flex, which they feel compounds the problem. I honestly haven't noticed any difference between the OEM and the Michelin Harmony wrt sidewall flex.

In particular, the Dunlop Graspic DS-2 winter tires have *way* more sidewall flex, and they also have a heavily siped, soft, and squishy winter tread. So if anything the car should be uncontrollable at highway speeds, but no difference on dry roads and *way* better on icy roads.

Some folks have also commented on how the "soft" suspension contributes to this problem. I don't see how they can call the suspension "soft" as I find the ride bone-jarring over frost heaves and potholes.

I've had the rear suspension checked by Toyota and by an independent tire shop: both concur the suspension is tight and within spec. The independent tire shop also checked to see if the suspension bushings were too soft but they claim the bushings were fine.

If the suspension bushings were too compliant, then every car out there with a soft ride would be all over the road at highway speeds. I have direct access to a car with *very* soft ride and *very* compliant suspension bushings: my parents 2003 Buick LeSabre.

That thing rides so soft you pretty much would have to be off-road before noticing the texture of the road. Yet at TransCanada speeds of even 120 km/h, it's strictly 1-2 fingers on the wheel. It tracks like it's on rails.

I don't think this is the result of overactive imagination or poor driving skills. There must be a variable combination of tolerance factors that add up - in the wrong way - to result in the poor highway stability.

After 2 "courtesy" alignments my Toyota dealer told me they were not authorized to do any more alignments free of charge, as the Prius met their specs. They also admitted the Prius is not the best highway cruiser in Toyota's inventory.

I've test drove the Echo Hatchback at TransCanada speeds of 110 km/h and it felt *much* more stable. Even my 1984 Ford F-150 tracks better at highway speeds.

As much as I like my Prius, there is no way I'd consider it for a drive of 3-4 hours anymore as it leaves me very tense and stiff. In contrast, if I take the folks for a drive to visit relatives, I can be behind the wheel of their LeSabre all day long and not even notice it.

As long as my Prius spends +95% of it's life in Winnipeg at less than 80 km/h, this isn't a big deal for me. If I had to do a lot of highway commuting I would seriously consider a different vehicle.

 

I believe Toyota just updated the 05 Prius, including improving the cars straight line stability, improving the power steering feel, and firming up the suspension. I'm not a mechanic, so this is what I recall reading, I might be wrong.

 

Jay- That's terrible. I wouldn't let it go. I can assure you it's not normal for this car. We now have two and I've driven both now at high speeds and it just doesn't happen. I think this has to be reparable. There are several people on this site as you recall that have taken their Prius to speeds above 100 mph without complaint. My car at speeds above 90 mph is smooth as silk, though I really don't spend time at those speeds beyond testing the car a few times.

My point is just that there is no reason to accept this poor performance as normal or unavoidable. I think I would take it somewhere that specializes in suspension work if the dealer is not up to the task of deciphering the problem.

 

I think the upgrade a previous poster was referring to is for European spec Prii. It sounds like this should be available to us, but it isn't. I believe I may be one of a few members on this forum that has had this car since it came out (picked it up 11/8/03). I never experienced any difficulty driving this car on the highway UNLESS there was a substantial headwind or crosswind. Even in those conditions, I was able to deal with it. Compared with my Liberty, it was a piece of cake to drive and sit back and relax. Granted this car does not go down the road like my '02 Audi allroad (sold it for the Prius!!!!!!!!!!), but with a tire changeout (got Nokians) the car tracks true and is very easy to drive. If you want to feel white knuckles just drive a Subaru WRX wagon (yup... had one of these too!!!) next to a truck's wake. Talk about fright!!!!!!!!!!!!

 

Ray:

I've taken my Prius to what is reportedly the best Toyota dealer in Winnipeg, which just happens to be where I purchased it. They are genuinely concerned about this but have admitted there are tolerance factors beyond their control.

Get this: the salespeople are now instructed to try to talk potential Prius buyers out of the car *if* they plan to do a lot of highway driving! They even try to talk a potential Prius highway driver into something like an Echo Hatchback.

I have also taken the car to a suspension shop with a very good reputation, they also do a lot of frame and alignment work on custom hot rods. They know suspensions.

In their opinion the tall, narrow profile of the Prius, combined with the very low Cd, can cause enormous tracking problems at highway speeds. That's if everything isn't just perfectly in tolerance. They didn't know how to check the EPS but when they checked the rear suspension alignment it was borderline, at the edge of the spec.

Magazine testers have commented on the tracking stability too. Especially that Australian review where they felt the car was a handful at highway speeds.

I'm not saying the car is dangerous. It's not like if I let go of the wheel it veers into a tree and bursts into flames. And at speeds under 80 km/h, no matter what the wind is doing, it tracks just fine.

It's just that the car takes my full attention to drive at highway speeds, especially if its windy out.

I've had cars and pickup trucks that, due to suspension problems or alignment problems, were a handful at highway speeds. But once given an alignment or new balljoints or whatever, they were very easy to drive at highway speeds.

I think the next step is to try to either relocate the chin spoilers - in front of the front tire - to the very front of the car. This appears to be very easy to do and I'll try it next time out to the hobby farm.

If that does the trick, I'll just have to remember to be a lot more careful approaching curbs. I also found a speed shop here that can make a custom spoiler for under $200 and that might also be a good solution.

Jay

 

Jay:

Apologies if this has been discussed before, but a question: what PSI are your tires inflated to?

I just wondered if this could be a factor. I've left my tires at the recommended 35/32 psi, which is supposed to be a more comfortable ride, but gets worse MPG.

However, driving in Seattle, I've rarely (if ever) encountered the kind of road conditions you're describing, so I definitely have no experience on the subject.

 

Jeff:

When I first joined PriusChat the highway tracking issue was still very fresh, as FredWB was posting a lot of extensive detail on his problem.

I tried playing with the tire inflation quite a bit. I went lower, down to 30, all the way up to 44, tried no bias, and even tried changing the bias around.

Eg: 30F/30R, 35F/30R, 35F/33R, 38F/33R, 35F/35R, 30F/35R, 44F/42R, 44F/44R, etc.

There really was no difference in highway tracking that I could determine just by tire inflation. At 30/30 the car felt a tad more sloppy is all.

With the roads around here, at the most my fuel economy was improved around 3 MPG at 44F/42R. It simply wasn't worth the bone-jarring ride and I now run 35F/33R.

Jay

 

Thanks Jay. I was sure you would have taken that into account, but I was curious if it had any effect.

I agree with Ray -- very scary. I'm glad I haven't encountered that on any of my infrequent interstate road trips!