Car did not move forward when flooring down the power without/with slip start. What was the reason?

[coolmanfever]

Yesterday there was a huge snow blizzard in my area in Toronto and I decide to test drive my new 2020 SR+ rwd model 3 to its limit in the middle of snow blizzard. The car is equipped with brand new nokian R3 winter tires as recommended by many posters here.

When I took a left intersection turn, there was about 1 foot of snow in my way.I then got stuck in snow.

I tried to floor down the power and traction control signal kept showing up on the console. My car fish tailed multiple times but would not move forward.

I then enabled slip start and kept flooring down the power. The car kept fish tailing and could not move forward.

I spend a good 15 min flooring down the power pedeal with slip start enabled and without slip start. Finally the car was able to move forward with slip start enabled after 15 min of trying.

While this happened, I saw couple model 3 rwd driving pass by me easily.

So I started to wonder if there is actually a glitch with my car traction control and slip start software for the first 15 min? What do you guys would be the cause of this event?

Any comments and inputs? Thank you

 

[WesB]

Not sure if this is the answer, but it may have been obstacle aware acceleration. This is a setting that drastically reduces your car's acceleration when you try to drive into an object (in this case snow). Even if there was no snow in front of you this could have been triggered by your front facing ultrasonics being covered in snow.

 

[WesB]

Otherwise you may just have been caught on a bad patch of ice or snow that was hard to get out of. Remember you only have traction on your rear wheels. I got stuck yesterday and got out fairly easily by going forward/reverse in short bursts.

 

[coolmanfever]

Actually I tried to disable all safety feature like obstacle aware acceleration but the car still struggle to move forward. But I will try going forward and reverse in short bursts next time like you said. In fact, I am going to test it out in a empty parking lot when there is another storm next time.

 

[animorph]

The fishtailing just sounds like there was not enough traction at the rear, letting the wheels spin, And not enough traction at the start, before spinning the wheels, to plow the car through the snow. Nothing traction control can do to make traction. Reverse and forward momentum required.

 

[ckoval7]

Flooring it on snow and ice is never a good idea. Spinning your tires melts the snow/ice temporarily to create slippery, clean ice patches directly under your tires, just getting you more stuck. Always ease into the throttle when you're in those conditions.

 

[CrayZ1]

It's not a snow plow no matter what the nose is shaped like.

 

[lbowroom]

I would think chill mode and gentle application of throttle would be the prescription for that situation

 

[dsgerbc]

That's your regular RWD car w/o a real limited-slip differential.

 

[OUengineer]

Flooring it on snow and ice is never a good idea. Spinning your tires melts the snow/ice temporarily to create slippery, clean ice patches directly under your tires, just getting you more stuck. Always ease into the throttle when you're in those conditions.

Unless you have a modern brake based AWD system. With those, you need to floor it so that you have enough torque to overcome the braking forces and send power to the wheels that have traction.

With Tesla's system, it probably doesn't matter what you do as it sounds like the system will just do what it wants no matter what inputs you give it and it's either good enough to keep you from getting stuck or it's not.

 

[Phlier]

With Tesla's system, it probably doesn't matter what you do as it sounds like the system will just do what it wants no matter what inputs you give it and it's either good enough to keep you from getting stuck or it's not.

Yup, exactly.

Scenario 1: Electric car with no traction control system or ABS, and you put the accelerator pedal to the floor. Car says, "Boss wants it all! Let's give it to him!"

Scenario 2: Electric car with traction control system and ABS, and you put the accelerator pedal to the floor. Car says, "Boss wants it all! But lets check the traction situation out first, and only give him what we can do without spinning the wheels."

The OP's situation is simple; if there isn't adequate traction to move a two ton vehicle forward, there is just no way the car is going to move. Traction control < laws of physics.

BTW, most ICE vehicles will pull timing (and sometimes even limit fuel) in addition to using differential and modulated braking when you mash the gas in low traction conditions.

 

[CrayZ1]

Unless you have a modern brake based AWD system. With those, you need to floor it so that you have enough torque to overcome the braking forces and send power to the wheels that have traction.

With Tesla's system, it probably doesn't matter what you do as it sounds like the system will just do what it wants no matter what inputs you give it and it's either good enough to keep you from getting stuck or it's not.

Modern AWD systems have a 'low traction' mode. This is designed to get you unstuck or to get you moving. Test a JLR vehicle with AdSR to see what you're missing. They also have 'ascent control' which acts much the same, but is for climbing scary steep grades.

 

[640k]

i've never, ever heard of "flooring" the accelerator to get out of ANY condition. i don't care what nanny controls are in place. this is news to me.

OP posts: I floored the accelerator and the car fish-tailed. But everyone else was just fine!!!

I mean, really?

 

[ewoodrick]

Yesterday there was a huge snow blizzard in my area in Toronto and I decide to test drive my new 2020 SR+ rwd model 3 to its limit in the middle of snow blizzard. The car is equipped with brand new nokian R3 winter tires as recommended by many posters here.

When I took a left intersection turn, there was about 1 foot of snow in my way.I then got stuck in snow.

I tried to floor down the power and traction control signal kept showing up on the console. My car fish tailed multiple times but would not move forward.

I then enabled slip start and kept flooring down the power. The car kept fish tailing and could not move forward.

I spend a good 15 min flooring down the power pedeal with slip start enabled and without slip start. Finally the car was able to move forward with slip start enabled after 15 min of trying.

While this happened, I saw couple model 3 rwd driving pass by me easily.

So I started to wonder if there is actually a glitch with my car traction control and slip start software for the first 15 min? What do you guys would be the cause of this event?

Any comments and inputs? Thank you

I'm going to take a first guess that you slid up on enough snow that while the wheels were on the ground, there just wasn't enough traction to move you off the snow. With the plastic cover on the bottom, this isn't hard to do.
The 15 minutes of trying was probably the car slowly packing the snow down.

 

[coolmanfever]

thanks for all the feeback. I have never owned a rwd car before owning a model 3 rwd. Always had AWD cars. I would admit maybe I pressed the power pedal too hard while stuck in the snow.

As recommended. I should try to rear the car a bit and drive forward by pressing down power pedal when I use slip start.

 

[Dolemite]

OP subscribes to the Colin McRae mantra - if in doubt, flat out.

 

[ewoodrick]

thanks for all the feeback. I have never owned a rwd car before owning a model 3 rwd. Always had AWD cars. I would admit maybe I pressed the power pedal too hard while stuck in the snow.

As recommended. I should try to rear the car a bit and drive forward by pressing down power pedal when I use slip start.

If it has driven up on snow, you just can maybe just rock the car in all directions. But if the snow in front of you is just a deep, you aren't going to go far.
Look at the underside of the car. Measure the distance from the plastic to the ground. If snow height is greater than this, you may get stuck.
I had a Honda many years ago that I was coming off of a hill into a roadside parking lot. It indeed rode up onto some snow and none of the wheels had enough grip.
Got out, looked at situation, rocked car, moved some snow and drove away.