The Prius sucks in winter.

<div class='quotetop'>QUOTE(onerpm @ Feb 28 2007, 04:20 PM) [snapback]398036[/snapback]</div>

I generally inflate to 42/40 but don't check too often (and of course pressure drops with temperature). I don't think a lower pressure would have made much difference in that incident - the TRAC kicked in even with little or no pressure on the accelerator!

The REVO1 winter traction is much, much better than the OEM tires, but just doesn't seem as good as with our van (AWD Sienna with Michelin 4X4 Alpin in the winter) or my previous vehicle (4WD RAV4 with Dunlop Grandtek SJ4 in the winter IIRC). It seems much easier to trigger the ABS as well as the TRAC.

When they were new, I thought the (relatively) poor performance was because they hadn't worn down to the multicell layer yet (the outermost layer when brand new isn't multicell). We put 9,500 km (6000 mi) on them last winter, and about 8,000 km so far this winter, but the tread doesn't look worn at all. I haven't noticed them getting better or worse since new.

Maybe my expectations are just too high.

I suspect the high-torque-even-at-low-rpm of the electric motor is often too much for the tire grip in slippery conditions. Perhaps when TRAC is triggerred it should switch to ICE only (to lower the torque but still turn the wheels, kind of like slipping the clutch with a manual transmission).

 

<div class='quotetop'>QUOTE(redryder @ Mar 1 2007, 12:10 AM) [snapback]398256[/snapback]</div>

Red,

Good point, and on reflection, I'm sorry to have criticized. I think most of the responders were thinking of the OP and the thread title, and relating it to winter.

I've had 3 Prii: a 2004, 2005, and now a 2006, and I have not yet experienced any TC problems in warm weather situations. However, I don't recall being in any circumstances that would have given it a test.

So, to turn the thread back to winter, I will report that my Blizzak Revos, combined with the ABS, stopped me so well at a red light at lunch today (we're having another blizzard in MN) that a 4WD Ford Explorer slid into me from behind, putting a nice punch in my bumper and knocking it off-kilter on one side. To the body shop! First accident for me in many eons. Darn it, if I would have had the OEM tires on, I would've "slid" right through the changing light and kept going untouched!

rpm


<div class='quotetop'>QUOTE(afternoonnap @ Mar 1 2007, 02:49 AM) [snapback]398315[/snapback]</div>

I would think the Prius is a lot lighter than those vehicles; that's gotta matter. (although perhaps it would be an advantage when stopping...)

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Feb 26 2007, 08:16 PM) [snapback]396950[/snapback]</div>

My Prius does NOT behave like that when it bogs down. I really would like to drive a Prius that appears to operate "normally" in winter, then have the driver of that Prius drive mine, to confirm the awful winter performance of my Prius.

With studded tires, I can at least get moving on ice, but forget deep snow. With an "all season" tire, forget about it.

<div class='quotetop'>QUOTE(redryder @ Feb 27 2007, 12:05 PM) [snapback]397198[/snapback]</div>

Yep happened to me too. I commented on it on another thread. It was an expedition to a tourist camp to go fishing for a few days. In the convoy was Yours Truly, a co-worker in his VW Golf tdi, and another co-worker in his Lexus RX300.

The gravel sideroad, combined with steep hills and sharp turns, meant I couldn't get a run and the car just came to a stop. In the end, the co-worker with the RX300 suggested we use the Emergency Eye Bolt in the front bumper, and he hooked a towstrap to his tow hitch. He had to pull me up the hills.

The co-worker with the VW Golf tdi had ZERO trouble. He even stopped on one hill, then let out the clutch and got going again, with very minor wheelspin.

<div class='quotetop'>QUOTE(afternoonnap @ Mar 1 2007, 02:49 AM) [snapback]398315[/snapback]</div>

Actually, the first 45% of the Blizzak is the special Tube Multicell tread, the remaining 55% is regular tread. This is stated at the Bridgestone site.

I tried both the Dunlop Graspic DS-2 and Yokohama Ice Guard 10 studless winter tires. Compared to the Michelin Harmony all-season that I normally run, the Dunlop's and Yokohama's offered superior snow and better ice traction. I still had trouble on glare ice.

This winter I'm running studded Goodyear Nordic tires from Canadian Tire. It's the same as the Goodyear Ultra Grip 500 sold in Europe

http://eu.goodyear.com/home_en/tires/repos...p?page=benefits

Even studded, they only cost around $122 a tire. They are VERY noisy on dry roads, but really perform well on ice. The tire also works very well in snow, better than the Dunlop or Yokohama did.

A co-worker really swears by the Toyo Observe G-02 Plus. This studless winter tire has the winter compound the full depth of the tread, not just half the tread depth. It also has ground up walnut shells in the tread, which appear to work just as well as studs on glare ice. I've driven his Honda Accord and it will easily blow the doors off my Prius on snow and ice.

 

<div class='quotetop'>QUOTE(jayman @ Mar 1 2007, 08:36 PM) [snapback]398794[/snapback]</div>

Not quite. The very outermost layer, when new, isn't multicell. As stated here: http://bridgestone-firestone.ca/eng/news/r...es/08_25_05.asp
"A cross-riblet surface provides ice traction for a new tire until the Tube Multicell compound is exposed."

That's what I was referring to.

 

<div class='quotetop'>QUOTE(afternoonnap @ Mar 4 2007, 03:24 AM) [snapback]399821[/snapback]</div>

Gotcha, this is similar to the Yokohama Ice Guard 10. In that case, a brand new tire should have BETTER ice traction than once that special top layer is worn off. At least that is what Yokohama claims for their Ice Guard 10 tires.

It gets me all worked up to think of less than 5% of a winter tire with the "ice traction" compound, the other 40% or so with the special "winter" compound, and the remaining 55% as a regular all-season compound.

Feh, that's why I went back to studded tires, noise and all.

 

Well, my Prius and X-Ice tires experienced it's first real winter test this weekend as I journeyed to Montreal to visit my first newly-arrived little niece for the first time.

The big storm that hit most of Eastern US & Canada last week hit Toronto Thursday night, of course matching up perfectly with my travel plans. <_< Some called us crazy for following through with it! :lol:

The wife & I left at 3:30 Friday morning and faced snow, slush, sleet, freezing rain, rain, then snow again and of course strong winds throughout. Although slow moving (highway didn't feel safe going above 50MPH), she handled the conditions like a champ. IMHO, the crosswinds were more of an issue than the road conditions. This trip alone made the tires worthwhile.

In Montreal, they were hit with 12"-14" of snow. Never once did I get stuck, pushing my way through a couple snowbanks and even wedging myself (in reverse) into an unplowed parking space with about 6-7" of snow. Later pulled out of the spot no problem.

Didn't encounter any situations where I thought the TC worked against me, which definitely makes me to believe the programming on the 06/07 is definitely "different" from the 04/05 who report all power is cut, as it did feel like there was some wheelspin when it kicked in.

Just thought I would share...

 

To all of you asking, "why can't you shut off the TC", the answer is, "because spinning the wheels could damage the transmission".

MG1 and MG2 can't be overreved without causing damaged. That's why the engine ALWAYS turns over 41mph, and it's why there is TC - spinning the wheels could result in an overrev situation.

Now, the TC algorithm could probably be improved (it's pretty agressive), and you might even be able to make a "TC off" mode where TC is enabled but alows a larger degree of slipping.

The reality is, though, the Prius with its OEM tires performs as well as any other vehicle I've owned. No, it's not going anwhere with 6 inches of snow on the ground, but neither is any other front wheel drive vehicle. It's always been my attitude that you shouldn't be on the roads when they are covered with ice/snow, but I can understand that you might want the ability to drive in the event of an emergency or other contingency. In that case, the Prius is not your vehicle - the TC is too agressive and there isn't enough ground clearence.

Here in Colorado, blizzards are pretty rare (except for this year!), and we don't have any problems with 2WD vehicles. It means that we don't drive 3-4 days out of the year, and that's OK considering that we wouldn't feel safe driving on those days anyway.

 

<div class='quotetop'>QUOTE(bsoft @ Mar 7 2007, 07:13 PM) [snapback]401927[/snapback]</div>

Well, in that case I would have had most of this winter off. Some of us do appear to own a Prius that is way over the limit for extreme aggressive traction control programming, despite having all flashes and updates.

It's one thing when every other car is helpless, then you say "oh well, bad weather." But if your Prius on "all season" tires is helpless when one side is on ice, and the other side is on pavement, and cars behind you are honking to get moving, then you say "Wth is wrong with this car?"

I solved almost all the TC issues by running very noisy, aggressive studded tires. Indeed, on ice I can blow the doors off any pickup or SUV running "all season" tires. But once the car bogs down, I can keep it floored, and the wheels refuse to even budge.

 

Had the opportunity of driving up a very steep muddy and icy dirt road the other day. As John pointed out, the car "paws" at the road and goes up slow, but it does go up.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Mar 7 2007, 11:01 PM) [snapback]402060[/snapback]</div>

Hmmm... Tideland, you quoted jayman but mentioned me... just to be clear, I am in the camp that doesn't have any problem with winter (so far, anyway).

I am still interested in the situation that you previously said, that you used to have the same winter problems others describe, but after a servicing on the car the TC behaviour changed (for the better). Has there been any confirmation from Toyota that they did in fact modify the programming (such as 06+), and if so, can't everyone else with 04/05 go get it updated as well?

Or does Toyota still deny there is/was a problem with the 04/05 system? :huh:

 

1) OEM tires will slip in the summer on gravel and sand, even a little patch. Replace them.
2) I have gotten TOTALLY stuck only once and that was on Valentines Day. 27.4" of snow in 24 hours - record for the area. I think about 24" were between 5 AM and 5 PM (when I left work) given how much was on my car at those times. The road crews weren't even close to keeping up. There were hills I couldn't go DOWN because of the cars stuck in front. I worked my way around to a more flat routes only to run into unplowed intersections with more stuck cars. With a lot of forward and reverse (fortunately the computer controlled transmission won't strip itself ) I worked my way around. I got stuck trying to get through a snowplow created bank to a more major (and FINALLY plowed) road. Several cars and vans and trucks were stuck there. More reverse and forward. Some of the stuck people tried to help by pushing from behind. I appreciated their willingness, but I think it took longer because I thought it best not to back up and run them over when the TC kicked in Finally got through and parked across the street to help them. ALL the cars had true snow tires (I have Triple Treds), ALL had more clearance than my Prius. Without TC, their tires spun and forced the cars down deeper into the snow. So, at least in THIS case, lack of TC made things WORSE not better. I convinced them to back up and run my tracks rather than force their way forward. With some diggging of snow from behind their tires and pushing from the front, they also got out.
From there I continued on my way, including a road than had at least 8" of snow on it but no one had been on it. Got through with no problem and no TC engaging. I got permanently stuck 1/4 mile from home. The road had at least a foot of snow on it (by now it was 7:30 PM and the road was last plowed at noon). There were a couple of deep tracks on it and I just couldn't push through. The shovel brigade came up from the house and we cleared down to about 6" in front of the car for about 100' (filling the ruts from the other vehicle) and I got up enough speed to hit the relatively steep down hill to the house.
Thus, the morals of the story are:
1) TC is not necessarily a villan when you are stuck
2) You need something better than OEMs in the winter and they aren't too good in the summer either. I figured this out year one. I don't know that true snow tires would have helped in this situation given the status of the taller vehicles that had them. I didn't get stuck due to lack of traction, I got stuck because the front bumper isn't snowplow shaped and the car was sitting on top of the snow, no tire is going to grip on snow it can't pack
3) Carry a small shovel so you can create path if necessary.

 

Well, I just got in from the hobby farm. We've really warmed up, highs were +45 F and lows down to about +30 F. The gravel sideroad to my hobby farm was covered with about 6 inches of ice and hardpacked snow, now it's all soft and mushy.

To confirm that my Prius "traction control" is still acting up, I purposely stopped on one small hill. Pressed the gas pedal again, nothing, TC light flashing. I floored it, nothing. So I had to back down the tiny hill, then take a run at it.

My dealer claims my Prius has all current reflashes.

In case anybody is curious, before I left I cut a check on a yellow FJ Cruiser "C" package. It should arrive sometime next week, then I'll have a competent vehicle to take out to my hobby farm. That will be its only purpose, so I probably won't put more than 6,000 km a year on it.