tire spinning or battery spitting?

To me it sounds like the car IS performing . . . traction control.

 

Perhaps you could be a bit more specific. Are you talking about highway performance or starting-line acceleration? Please describe the circumstances and symptoms in more detail, and you'll have a gaggle of folks giving you performance advice.

 

Did you have the front wheels turned when you noticed this?
I'm a new Prius owner and I get this a lot. Seems like it can't make up its mind whether to use the battery or ICE for a split second. But I don't notice it when I'm pulling straight ahead.
Scares the H**L out of you. Feels like the cars stalling. ;-)

 

And if the engine is not running at that moment (and if it's already warmed up, it probably isn't) then there is a slight lag while the engine is started and begins to provide significant power. Try less-than-flooring it for the first half-second and see whether that helps the feel.

 

I had noticed this too but wasn't sure what to think. For a while I was convinced that this meant a trip to the shop. But like most things in life, you learn to adjust to it and all is good. I naturally evolved my driving technique and now do the moderate acceleration with plenty of zip. This car continues to amaze me by showing me how to DRIVE BETTER.

 

Root cause is the factory tires aren't very "grabby." When you floor the accelerator from a stop, the Prius generates more than enough torque to exceed the tires' ability to hold static friction, which results in a spin-out.

In a "normal" vehicle, this would result in much squealing of tires and leaving of tread.

In the Prius, however, the traction control (not to be confused with vehicle stability control) kicks in to prevent the transmission (PSD) from being destroyed by overreving, and the power to the wheels is interrupted or greatly reduced for about a second, causing the vehicle to feel as if it has stalled.

In heavy traffic, this is dangerously annoying, especially when the traction control stalls your acceleration while attempting to pull out in front of an oncoming Hummer.

The solution is either to upgrade your tires, or to adjust your driving style: When starting off the line, accelerate slowly for the first 5MPH or so, then feel free to floor it. Be cautious when your tires are on wet, slick, or painted (e.g. a crosswalk) surfaces, as these will encourage tire slippage.

Given proper tires and surface, this car can really zip off of the starting line. No engine can develop the kind of starting torque that is delivered by an electric motor!

 

My daughter-in-law had something like this happen to her recently.
She was in the middle lane of an interstate in MD driving in light
snow, when she said the car just started slowing down even tho
she was pushing on the gas.
She was able to get over to the side of the highway and stop.
She called my son on the cell phone and he told her to try to go again.
She did and every thing was fine the rest of the way home.

By the way they got her car the last week in Dec. 2004 and she already
has over 10,000 miles on it (74 miles one way to work).
She is quite happy with it. They traded in her 2003 Ford Escape for it.
She was stopping for gas 2 times a week before. I forgot to ask her
how often she stops now.
Charlie

 

That sounds like a different problem that may need attention, though it should have lit the big bad triangle if it was what I am thinking. There is a re-calibration programming for that.

If traction control is activated, you should see a yellow car with squiggles (slippery surface) symbol briefly blinking. Sometimes though TC is so brief, the icon doesn't light.

 

As far as I know, the vehicle slip indicator (car with squiggles) only comes on if VSC (vehicle stability control) - not the traction control - is activated. Or do they both trigger the slip indicator?

VSC is inactive at speeds below 9MPH.

I agree that this is a completely different problem. If the VSC wasn't beeping like crazy while your daughter's car lost power, I'd say it's time to visit the nearest service center.

 

Generally (to me anyway), when you are at a light long enough for the gas motor to shut down, and then step on it, there is a lag before things get going. AS someone mentioned, if the motor is cold, it is worse.
If the tires were really spining you couldn't miss the indicator.

 

Evan:

Nope, you did good son.

I think the Trac is too aggressive, but it has to be to prevent the enormous electric torque from destroying the PSD.

I knew the Trac was too sensitive when we had our unusual sleet and freezing rain here, back in November. I tried driving up an icy parking ramp to an upper deck and the car just *stopped* on me.

Right to the mat, the VSC icon illuminated, and the car stationary. Fortunately, nobody was behind and I was able to back down. Oh, I did some experiments in an empty and icy truck parking lot, the Trac also works in reverse.

I solved most of this annoying problem by putting on Dunlop Graspic DS-2 winter tires. With those tires, on snow and ice the Prius will happily blow away other cars and 4WD's with all season tires on them.

The aggressive Trac is something you learn to live with. There is no disable button.

 

Trac isn't too agressive.. tires just suck. Electric motors have 295 ftlbs of torque at 0mph... that's the same torque my High Output 5.0L V8 had at around 45000 rpms... with other tires, it no longer does this.. unless you really really punch it and turn.. but that's a given. there is a difference between acceleration out of parking lots and attempting do donuts.

 

Yeah, I was referring to the original post. I have never had traction control come on in the car, so I wouldn't know what it felt like. I just feel that hesitation waiting for the gas motor to kick in when leaving the light.

 

Depends on where you live... ever taken a drive through lovely Boston?