Power lost on slightest spin of tires

Bill, you're wrong.

If I'm on 2 inches of ice at 0 degrees, then a little wheel spin is of no use, it's not going to help.

If I'm in 2 inches of slush at 31 degrees and I could have a little wheel spin to displace the slush and get me down to pavement, then I could definately benefit from it.

You don't need drive train suicide to fake the level of wheel spin that would help here. With any other car, you'd be stupid to floor it to get past this slush, but, you could give it a little wheel spin to cut the slush.

Having the car decide that you get .00005 % wheel spin gets you nowhere in this slush situation when a normal car would have done the right thing.

I don't have a Prius yet, but I'd say if it leaves you stopped in the above situation, that it was a design oversight that should be programatically corrected.

 

I have a question to all of those folks having a problem with the traction control.

What tire pressures are you running?

It's an old ice racer/off-roaders trick to LOWER the tire pressure to improve grip. These cars run with tires in the 5-10 psi range.

If you are running pressures in the 40+ range to improve MPG then you are paying for the loss of traction by reducing the tire contact patch. We have tires that are only a little larger than some motorcycle tires. I have not a problem yet here in Michigan with our 2006 but then I am running the tires at door sticker pressures - 35/33.

Ed

 

I responded once but don't see it. Sorry if it shows up as a duplicate.

Yeah, I would like to hear more from you about lawyers, in the appropriate thread.

I don't want a HH or RH. I just want my Prius to give me the wonderful results some of you others are experiencing.

I only wish that one of you could come up here and show me how to even get my car moving when it's icy.

 

My prius does fine in the snow and ice. Much better than my old Mercedes.

As stated above on ice wheel spin does no one any good. Just makes you think it's trying harder.

But on slush where you can dig down to the pavement, the car works fine if you have the right tires. I use Michelin Xice, and only have problems on hard wet ice.

Traction is fine and wheel spin is a non problem on snow, packed snow, slush, etc.

I have an icy hil near my house that I could never get up in my old car when it was slippery. Prius goes up it fine long as I don't stop on the hill.

About the only way Toyota could improve this is to use separate motors for each front wheel, or have a 4 wheel drive option.

 

I agree with traction control, but it looks like it would be very easy to disengage it at stopped or slow speeds and simply put a rpm limit on the spin of the wheel... that shouldn't be so hard?

One thinking says if you have no traction.. spinning the tire will not help either.... 0+0 = 0!....
But if you have a little traction at all then it will... 1 + 1 = 2... the faster the tire spins, the little bits of traction are added up faster as the surface of the tire runs over its resistance points on the road or snow surface faster.

I don't know if this little made up theory of mine has any weight, but all I know is that there have been times when moving the tires slowly would not cut it when I was stuck in the snow or mud and the only way I got out was to let the tires spin fast and not let up!

 

I'd say your spinning wheels have 0 traction. In fact you should be able to move your car sideways as easily as forward with spinning wheels, unless you're on gravel or something, then you might get some jet propulsion from that.

Here's an experiment you can try: Put a block of wood on a horizontal ramp. Then raise it until the block starts sliding. That shows how much traction it had before sliding. Now lower the ramp a bit and see if it will slide down the ramp once put into motion. I hope that this would show there is a big loss in traction once you start sliding.

 

Seems to me a good way to dig yourself into a hole and really get stuck.

 

My main problem with the way the traction control is setup, comes when entering a main road from a dead stop when the road is dry. You are at a full stop, see a space between cars with enough time to enter, start to accelerate and you hit some loose gravel on the dry road and the car loses all power when the traction control kicks in. The space you saw to get on the main road quickly disappears and your left hanging half way into rapidly moving traffic and no power. A potentially very dangerous and deadly situation. The power should shift to the wheel that has traction rather than loosing all power.

 

If thats what happens.. I agree.. I haven't gotten my car yet to experience that thrill!

 

Very good FBear. This was my point--and problem--as well. No one pulls into traffic when there is ice/snow on the road. If they do, and get hit, they are at fault. However, under normal road conditions, we should have an expectation that our car will get up to speed at it's normal rate. This is not the case with my Prius. I can't trust it if there is any sand, mud, loose dirt, oil, gravel, etc near the entry point into traffic. As small patches of these debris are common where I live, this loss of power is a real safety concern.

Traction control is supposed to use braking to shift power through the differential to the wheel(s) with the best traction. It is NOT supposed to withdrawl power from any wheel. Perhaps the design of the Prius precludes that option. If so, the design may be defective.

I did not suggest anyone sue Toyota over this issue. However, such a suit may occur when this design is shown to have caused an accident.

For our Canadian friends, such suits are the most effective way to correct product defects. The government is too easily influenced by political interfence to fix such problems. And, of course, the government is slow, expensive and inefficient.

jrohland

 

I agree with FBear. Just because one tire is on some slippery doesn't mean the tire on good pavement should stop. Unless there is some design flaw with the system.
I was in Tahoe last winter (Integrities at 36/34) and was going up an on ramp. Just as I was at the merge part there was slush on the right half of the lane. I started "coasting" due to TRAC at about 50mph halfway into the slow lane. Scared me silly since traffic was coming up at about 60mph on my tail. Luckily as I coasted into more dry pavement TRAC stopped and I merged OK. I had my foot to the floor until the TRAC stopped.

 

Hiya FBear!
Used to live in NJ and agree; the merge requirements when driving in certain areas in that state are murder! If I moved back to metropolitan NJ, I'd get a V6.
Now live in rural MD and have had no problems with Foxy's traction control. Yes, we love living on the edge of the Chesapeake!

 

Who said anything about making a dangerous move and getting hit? I'll be the first to agree a reckless auto driver who is hit by a truck is totally responsible

1) When Toyota stonewalls it and says they are not aware of the situation ((problem?) as they did with my brother)) then why not at least talk a class action suit? This might be the only way to attract their attention. This is not a frivolous matter, it can be downright dangerous.

I know there will be those who respond and say they have never encountered the problem. I will say, in advance, good for you and I don't care. It has happened to me several times and I don't like it!

2) Some months ago, a PC user stated that he made a safe right turn with an oncoming truck coming on in the distance. He further stated that, for some reason, the traction control kicked in and what would have been a safe move without traction control almost turned into a disaster after the traction control kicked in. Sorry I can't point you to the exact message but I remember it clearly. Further, people are currently posting similar problems in this thread

Traction control can be downright dangerous and Toyota needs to address it.

 

I had a similar problem on my own driveway and wrote about it in another thread. I have a very steep driveway that makes a 45 degree right turn. The driveway was partially icy. When I went to make the turn, the car stopped! It would not do anything (like it was dead). I finally tried putting it in reverse. It let me back up. I have Michelin X-Ice tires inflated at 38 and 36. I grew up driving on ice and snow and have owned my home for the last 27 years with the icky driveway, have driven a multitude of different cars both front, rear and 4wheel drive up and have NEVER experienced anything like what the Prius did (or rather did not do). I don't really recall if the traction kicked in or not. It was really weird to have a car just stop and not let you accelerate, etc. The car definately has a problem. I hope it never happens again especially on a street with traffic behind me.

 

Reading this thread has me wondering about my pending delivery/purchase. I have to drive and my driveway is gravel, so my snowblower does not really scrape bottom. That plus the semi rural roads that get little salt, makes me wonder if this is a good car for me.... global warming or no global warming

 

This may be a very good point that should be questioned or presented to Toyota?..
I would sure be curious to hear what their answer would be!

Sooner or later this is gonna bite them in the butt when someone dies and there is a passenger that lives to testify!

 

I do believe there is a way to disable the traction control system - but it is meant for test purposes only (like when running the car in a garage etc.)

Turning the TC off might damage the HSD system as well.

 

Here is an interesting piece which describes traction control on edmunds.com

http://www.edmunds.com/ownership/safety/ar...52/article.html

Does traction control on the Prius fit the definition or should it be named something else?