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Toyota Prius - Traction Control vs Vehicle Stability Control

njresidentnjresident Posts: 6
edited May 2014 in Toyota
I am finalizing on the Prius and wanted to know whether one should invest the money for Vehicle Stability Control. As in 2007 Prius, it already comes standard with Traction Control.

Any thoughts/experience would be appreicated.


  • pathstar1pathstar1 Posts: 1,015
    Traction control helps you from spinning the wheels when you take off. VSC helps you maintain control if you start to slide while driving. Very good thing to have.

    Put another way, the TC is the system some owners wish the car didn't have, and VSC is the system some owners attribute to saving their lives.
  • missnicemissnice Posts: 1
    How does the Prius handle in the snow, ice and at higher elevations?
  • pathstar1pathstar1 Posts: 1,015
    Prius needs snow tires. The Goodyear Integrities it comes with don't do well in snow or on ice. It's important to keep the front wheels from spinning, because that will trip the traction control, and it's reported that can keep you from moving in certain conditions.

    I haven't heard anyone complaining about high elevations. There are a few owners in Colorado reporting that they do fine. Except in 2 or more ft. of snow, but that's to be expected. ;) Prius has low ground clearance to minimize wind resistance, and that can mean "plowing snow" if there's enough. Others report going over mountain passes in the western US with no problems.
  • dtenerdtener Posts: 2
    My prius just quit as I attemtped to navigate the hill to my driveway with snow and ice. As I tried to maintain momentum it simply went to zero. Did I do something wrong or is this an issue with this transmission or traction control?
  • pathstar1pathstar1 Posts: 1,015
    This is the issue I was alluding to. It seems to be "fixed" or lessened in the 2007. Some say if you keep pressure on the accelerator, it will try again. If not, you may have to shift to "P", then back to "D" and try again.

    Toyota had to set the traction control to very high sensitivity to protect MG2 (motor generator 2 - the one that moves the vehicle most of the time). If you spin the wheels on ice you could over-spin MG2 and destroy it, so TC protects it. Perhaps a little too aggressively. So far every posting of problems I've read has been on a low speed hill such as a driveway.

    So if you know you will experience snow or slippery conditions on hills, good snow and ice tires are a "really good idea" (tm). ;)

    If you're wondering why it over-spins MG2, it's due to the design of the HSD. The rotation speed of the ICE (internal combustion engine), MG2, and wheels depends on the speed of the other two devices. If the engine is off or idling and you spin up the wheels you also spin up MG2 (a lot). This is also why you can't have the engine off above 43 MPH - it will over-spin MG2. There is a good visual example of this on Priuschat you can mess with written in flash, I think.
  • Does anyone know where I can find a list of small sedans (2007 models) that have optional Vehicle Stability Control.
  • backybacky Twin CitiesPosts: 18,910
    This page shows ALL 2007 vehicles available with ESC in the U.S. There is at least one error on it, however--Elantra doesn't have ESC available at this time.
  • lalcottlalcott Posts: 2
    I'd love to hear more about Prius's performance on snow and ice.Often have to come home from work in snowstorms on a dirt road. I now drive a Subaru (with 4 snow tires in winter). It's a great car but not very fuel-efficient. Thanks for any comments.
  • stevegoldstevegold Posts: 185
    It's OK but: We live in Aspen, CO. and used to have two Subaru Outbacks.
    I do use snow tires on the Prius but not on the Outback.
    We always used the Outback when it's snowing or if we're going on a trip and snow was forecast.
    We just replaced the second and last Outback with a Hybrid Highlander and will hens forth use that whenever snow threatens. The rest of the time we use the Prius for short and long trips and the Highlander only around town if the Prius is already being used. (I think the Highlander was a mistake but we need a least one 4WD)
  • stevedebistevedebi LAPosts: 4,098
    "(I think the Highlander was a mistake but we need a least one 4WD)"

    I think the HH uses electric motors on the rear wheels, and that will not do for heavy useage (the motors overheat and simply stop working until they cool). However, for basic "occasional" AWD use it will drive those wheels.
  • dtenerdtener Posts: 2
    My 2006 Prius did fine until I tried a steep hill and the wheels would not spin because of the way the transmission and vehicle stability control limit the wheels from spinning but just driving on the highway in snow was fine. My only problem was on the steep hill in the snow.
  • lalcottlalcott Posts: 2
    Thanks for comments. My last 4 miles home are uphill with a few steep grades - anyone else who's driven a Prius up hills in snow, please pass on your experience.
  • stevedebistevedebi LAPosts: 4,098
    "My 2006 Prius did fine until I tried a steep hill and the wheels would not spin because of the way the transmission and vehicle stability control limit the wheels from spinning but just driving on the highway in snow was fine. My only problem was on the steep hill in the snow."

    This has been reported as being fixed by a change to the CU software, allowing the wheels to spin a little bit.
  • Glad this topic is here as traction control is a big issue in my decision on the next car (I live in Portland OR and we are expected to have a lot of snow and ice this year).

    If a Prius is Parked with Both left side wheels on asphalt/concrete, both right side wheels on ice or snow or gravel, and then the Driver then decides to accelerate....

    What happens?

    1. Prius goes nowhere (wheel spins, traction control cuts power)
    2. prius spins wheels on right side and tries to move
    3. Prius simply moves forward without problem

    3 is how the new Subarus I drove handle the situation. Huge traction advantage in winter, but the Subies guzzle gas by comparison.

    Comments? Is braking also an issue under those conditions?
  • pathstar1pathstar1 Posts: 1,015
    What happens depends on what traction is available. If you are going to rely on the tires that come with the Prius you will have problems. If you put -real- winter tires on the car it will go (I use Nokian WR tires). It may spin, wait, spin, wait, then go, if it's slippery enough. If you are on level ground there is really not much of a problem. Basically, it's pretty much like any other front wheel drive car. The only difference is the traction control is a bit more sensitive.

    With braking, it's no different than any other car. Even a Subaru will have trouble stopping on ice. It all depends on what tires you have on the car.

    In reading this topic (posts before yours) I see people are still confusing traction control, anti-lock braking, and VSC.

    Traction control will reduce or cut power to the wheels when you accelerate, if the wheels spin up. In the case of the Prius, it does this aggressively to prevent over spinning of one of the motor-generators (wheels can spin up faster than the engine can start up - if the engine is not running motor-generator #1 can be over spun if the wheels go faster than about 43 MPH or 66 kmph.) I have noticed this is less of a problem if the engine is running, so it looks like the computer allows for this condition.

    Anti-lock braking will vary braking power on each wheel if the wheel spin rate of that wheel is a certain percentage lower than the other wheels. Some are three channel (both rear wheels are considered one) and some are four channel (all four wheels are individually controlled). This system only works under braking. The Prius uses regenerative braking, as well as hydraulic braking. The regen braking is very effective in slippery conditions, as it is not as forceful as hydraulic braking. The big benefit with anti-lock braking is it allows you to steer around whatever you might be traveling toward, whereas if you just lock the brakes you cannot steer (car continues in the direction it was traveling until it stops or hits something).

    VSC, or vehicle stability control, also called dynamic stability control, and several other names, will use braking on individual wheels to correct a skid and may also reduce power, usually even before the driver realizes there is a problem. This is usually not under braking, but driving through a corner. It can also work while braking, in concert with anti-lock braking above.
  • My 2008 Prius slips even on flat roads in minor snow (less then half-inch). I assume I need to purchase snow tires (and new wheels). Are the Nokian WR tires suitable for the 2008 model? Is there research on the range of appropriate snow tires for the 2008 Prius? (not Touring edition) Many thanks -
    Silver Spring, MD
  • rcinmdrcinmd Posts: 139
    I have a 2007 Touring edition.

    I recently purchased a set of standard 15" Prius rims on eBay, and just had mounted four "performance" snow tires, not as aggressive as some out there in terms of deep snow capability, but better in terms of dry road handling and somewhat higher winter temps, the sort we have here in mid Maryland, other than the 2 and 3 foot snows we've had in the past.

    I purchased Hankook icebear W300s. Another tire that rated highly in the categories I was interested in, but not available at the retail level in this part of the country, was the Viking Snow Tech.

    Today's snow looks to be about 3 inches out here. I'll know when I leave work how it does on the standard Touring tires, unless the roads are cleared by then. Last February, just after buying the car, I did take it through the neighborhood on the unplowed street, about 3 inches, and had no trouble at all, on level ground.

    I know I will have to put up with the yellow TPM warning light while I have the snows mounted. And I also now understand that after I put the originals back on, I still might have to take it to a Toyota dealer to have the sensors re-registered.....I hope not.
  • pathstar1pathstar1 Posts: 1,015
    The Nokian WR works well on the 2007 and 2008 Prius. There are two available in the stock size - I got the higher speed/load rated one. If you get Nokian WRs you don't need to take them off for summer. They are true all-season tires but have the snowflake symbol on the sidewall so you don't need to "chain up" on interstates when that situation presents itself. This is why I got them. No need for extra wheels/changing wheels/tires as the seasons change.
    I got 185/65R15 88H. They are not cheap tires, so be prepared to pay around $100 each for them (best price I was able to fine on the internet).

    Just to complicate our lives, Nokian have come out with a new version WR, the WR G2. It looks even better on paper. It's lighter yet stronger (higher load/speed rating). It hasn't been out long enough to get peoples experience yet. A fellow over on Priuschat may purchase them to try them out. He was quoted $103 each from a local tire shop. Not a bad price.
  • We live in San Diego, CA and have a place in the mountains. Snow tires would not be practical. Any suggestions for chains or cables?
    I remember when we bought the car they had us sign something about using chains. Are the cables, like Super Z6 O.K. to use?
    The roads up there have signs that say chains are required, which I assume is in effect during snow and icy conditions.
    Celeste Kennedy
  • has the answer for low clearance Prius tires- a bit pricey and not for high speed or even a short stretch of bare pavement ... but on/off in about ten secs per tire with a little practice and once the hub-mounted assy is properly installed on the front(drive) wheels... must be removed for rotating tires is the only drawback I've found.
  • Good snow or all-season tires make a huge difference. Also, throttle control is important.

    Driving our '07 on slick roads for the first time at the beginning of winter felt pretty skittery. After some reaearch, we got Les Schwab "Observe" snow tires. They aren't studded but are supposed to act like studded and are relatively quiet. (Les Schwab is a western US dealer).

    In practice stops and cornering on very icy roads, they are confidence-inspiring. Also, no problem on mountain passes as long as the snow's not too deep.
    Putting on snow tires cost 4-5 mpg, but easily worth it because the car feels more like a Subie with studs (my previous winter car).

    Our driveway is 3/4 mile long, steep, with a couple of tight turns. With the factory tires, my '07 Prius lost traction in 1" of wet, new snow. With snow tires, it climbs quite well. Like any car, when it starts to slip, backing off very slightly helps to get the grip back.

    YMMV, but I've found the biggest problem with slick stuff (snow, rain or gravel) is that the Prius has a lot of torque and the traction control system doesn't manage it well if you just stomp on the gas.
  • andyuandyu Posts: 3
    We have a 2006 Prius with the GY (#1) package. It is very dangerous to drive in snow, which we have a lot of in Wisconsin because it cuts power to the wheels as soon as any slippage is encountered. That may be ok in the rain, but when driving in several inches of snow, there is ALWAYS slippage. Our old Chevy Cavalier gets around in the snow just fine. You just get on the gas and those front wheels just start chewing their way through the snow. In the same scenario with the Prius, you get on the gas and it dies leaving you helplessly waiting for someone to slam into you and kill you. It is not a fit car to drive in snow. If no one has been killed yet, they will be. This is VERY dangerous. BTW - Toyota says that's how it is supposed to work and refuses to do anything about it. They're going to regret that when the lawsuits start. Deliberately engineering such a dangerous design makes them fully culpable. It's inexcusable.
  • wwestwwest Posts: 10,706
    The secret to driving ANY car on the slippery stuff, especially FWD it seems, is learning to feather the throttle YOURSELF just up the point of losing roadbed traction and not beyond. Once TRAC kicks in it will not nearly have the finesse you could use were you to bother to take the time to learn.

    Use TRAC as an indication of conditions, not as something to rely on as help in those conditions, its actions are far to ROUGH-EDGED.
  • I HEAR YA MAN!!! I literally called my dealer today and told them the same thing that you just wrote about. The Traction Control on the Toyota Prius is very dangerous indeed! I live in NW Minn. where snow covered and icy roads are the norm in the winter. I'll give an example of a near death experience I've had in my 2008 Prius. One day while driving home on the split 4 lane highway that leads to my house I had to get into the turning lane to cross the other side of the highway. A car was coming at me about 1/4 mile away as I began to pull out from the median crossing. Since the turning lane and median were icy, as usual, the Traction Control kicked in which killed power to the wheels, as the other car was coming at me at 65-70 mph. Well, not only was it icy in the turning lane and median crossing but it was also icy crossing the highway. Needless to say, if the other car hadn't slammed on it's brakes to slow down for the idiot driving the Prius (THAT WAS ME) who was stopped in the middle of the road since my Traction Control wouldn't allow my Prius to move, I'd be deader than a doorknob! I have been stuck with my Prius 4 times. The deepest snow was 5 inches on a flat gravel road, and the least amount of snow was literally 1/2 inch of snow with packed and ice snow below it! THAT'S RIGHT! I WAS STUCK IN 1/2 INCH OF SNOW IN MY 2008 TOYOTA PRIUS! BUY 'EM WHILE THEY'RE HOT! OH DON'T TELL ME I DON'T KNOW HOW TO DRIVE! The car that sits next to my Prius has 921 horse power and pulls a low 10 second 1/4 mile! Did I mention that my Prius gets great gas mileage?
  • andyuandyu Posts: 3
    That's exactly what I'm talking about. I've had some close calls too. If I or my wife doesn't get killed, I'll cause someone else too as they try to avoid hitting me. I always leave LOTS of room if I'm in the Prius before pulling out into traffic in snow, even to the point where people behind me are honking and I still end up in close calls. People who were behind me waiting to cross an intersection have gone around me and passed me in disgust before I could get across.

    I also have a GMC Sierra 2500HD Duramax Diesel 4x4 with locking differentials. Now that's what you want to be in in the snow. I want my wife to drive the truck all winter, but she won't do it unless the weather is really bad because she says it too big and too hard to park, so she's frequently in the prius, which scares me. Saving a few extra bucks on fuel just isn't worth it.

    I'll have to sell it if Toyota doesn't come out with some new programming for the TRAC before next winter. It's a great little car in every other way, but this is just too dangerous. It makes no difference whether you stomp on it or gently feather it, or anything else in between, believe me, I've tried and the bottom line is it just doesn't go like it should. It's scary.

    My friend has a Highlander Hybrid 4x4 and gets around just great in the snow. I wonder how the Camry Hybrid does? Is it just the Prius's that are so badly engineered? Does anyone know how the Civic Hybrid does?
  • wwestwwest Posts: 10,706
    You know what...??!!

    Traction on ice or well packed snow requires a huge tread contact CSA and WEIGHT...!

    The Prius has neither...!!

    I wouldn't drive a Prius in adverse roadbed conditions, and if I was forced to, not without tire chains.

    And yes, I know, very well, tire chains on only the front of a FWD vehicle can turn hazardous instantly. So drive slow, VERY slow.
  • Guess what?! My wife has a 2008 Toyota Camry Hybrid and it has the same dangerous problems with Traction Control. She wants her 2006 Pilot back and I want my 2002 Camry back!
  • chadxchadx Posts: 153
    Has anyone that has reported the touchy traction control issues had their dealers do a software upgrade as outlined in previous posts? I'm curious if that has helped since some report the '07 and later Prius isn't having as much trouble with this issue and allows for a bit more wheel spin.

    On a side note, this can be an issue with any type of car. Some traction controls interfere more than others. We had a rental vehicle, on vacation one time, and that Buick flat out stopped and wouldn't even put any power to the wheels with the slightest amount of wheel spin on snow and ice.

    As always, tire selection and driving technique make the biggest different, but and overly-aggressive traction control system can be a real pain. Some amount of wheel spin allowance can be a good thing in many situations. I regularly turn off the traction control on my wifes car (rear wheel drive and manual tranny) in snowy conditions. That being said, simply putting a couple bags of sand over the rear axle made a huge difference. Not an option with a front wheel drive, but the engine is already weighting the drive axle (the main reason front wheel drives have a traction advantage in snow).

    The stock tires on the Prius are built for mileage, not traction/permorance. Moving to a snow tire (such as Blizzak) would resolve winter traction issues in all but the most extreme situations. If one isn't willing to go to a dedicated snow tire (and the associated second set of wheels and the twice-yearly swaps), find a good all-season with the best snow rating you can find. That, too, will make a huge difference over the stock tires and completely change the personality of the car in those conditions, plus you don't have to swap them in the summertime.
  • chadxchadx Posts: 153
    Question about the details of the Prius traction control cut-out...Does it behave like other traction control systems where, if you immediatly let off, you can lightly feather the throttle and immediately make an attempt at accelrating again? Or is there some few second delay, unlike a non-hybrid system? Such as, it will absolutely not try and turn the driving wheels at all for a second or two?
  • wwestwwest Posts: 10,706
    The traction control firmware in a FWD is intentionally more aggressive, "intrusive" than a RWD or R/AWD and even F/AWD. That's because loss of traction at the front can too quickly result in loss of directional control. Whereas with loss of traction at the rear you still have "command" of the stearage.

    And remember that those electric motors have absolutely "stellar" low end, low speed, TORQUE. Perhaps you need a "snow" mode.
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