stopping on ice

I've noticed that allot of guys on here say they can't stop any better on snow and ice in 4 wheel drive than they can in two wheel drive. Maybe I'm wrong here but my Tacoma seems to stop much quicker when I have it in 4wd. Has anyone else noticed this or am I the odd duck here?

 

4 wheel drive has no effect on braking

 

The only effect 4wd would have on breaking would be if you have a 5 speed and you are down shifting. Stopping on ice??? Shit I can't even walk on ice, never mind stopping on it. The only way you can stop on ice better is with studded show tires, even then it still sucks.

 

Keep OFF the Ice

 

I know everyone says it makes no difference, but I still argue that having 4 wheels stopping you equally, will stop you quicker than two wheels sliding and two pushing.

 

4WD makes you go. Tires make you stop.

Our perceptions can skew reality. An interesting research study would be putting people in a car, stopping on ice with 4WD on and off, but the participant to be unaware of the 4WD status. Then to gauge the real variance in reality vs. perceived reality.

 

Well technically your Tacoma 4x4 only has power to any two wheels at a time (one front and one rear) unless you have and are engaging the locker.

In any case the best way to get a benefit from the 4x4 is to gently accelerate to regain control of a Tacoma sliding on ice (in most situations) since 4x4 only helps out when sending power to the wheels.

All cars have 4 wheel braking. None are really better then others (assuming an ABS braking system is in use as this does provide a significant advantage). But tires make a difference, as does having extra weight in the bed (I keep about 100-150lbs of sand bags in my bed all winter and it does make a difference in my braking and traction on ice. Studded, sipped, or chained tires help too. Even the brand and design of the tread can matter.

Anyway, almost everything helps except for the 4x4 system when braking on ice.

So, I say why brake, accelerate. (whenever safe and appropriate to do so of-course).

 

I agree with what you are saying. I've tested this numerous times and I swear mine stops better in 4wd.

 

Be very careful downshifting on ice even in 4WD...can put you into a spin and into the ditch real quick. Don't ask me how I know this.

 

In 4x4 or 4x2- The FRONT brakes still do the majority of the braking. Engine braking (assuming proper shift patterns) will slow the rear wheels as the fronts slow with the brake force.

Engine braking might slow you a bit faster with the additional extra load on the engine- But 4x4 isn't the fix all for slippery conditions....It can become 4 wheel slip just as fast as a 4x2 vehicle

What is the "test" protocol?? Weather and road conditions? Pedal pressure?? Are you measuring seconds to stop or distance to stop?

 

I should have mentioned that I have an automatic tran. although this may not make a differance.

 

chains will be ur best friend on ice

 

I think I know why you think you're stopping quicker. I'm guessing here that your perception of stopping quicker is from the moment you want to stop, not the moment you hit the brakes. With it in 4wd, you're going to have more drivetrain resistance when you let off the gas. So in effect, the vehicle is beginning to slow more in 4wd than in 2wd when you let off the gas. You'll really feel the difference by just putting cruise control on (don't test this perception on ice, though!) and leave your foot resting on the gas pedal. The moment you decide to stop and shift your foot from the gas to the brake with CC on, you're gonna feel like you've accelerated! You get just the opposite feeling of stopping quicker switching back to 2wd (due to drivetrain resistance and engine braking). Going to 4wd only adds more resistance, so you feel like you're stopping much quicker.

Now if you were to time it from the moment you're hitting the brake pedal, you shouldn't see a difference at all. As noted above, 4wd is irrelevant when you are trying to stop quickly with the brakes (thus the reason why "flatlanders" traveling up into the mountains cause so many accidents on the freeways..."I have 4wd, therefore I can drive faster in the snow").

 

No spacific test here, just going by feel.

 

^^This

 

Kinda what I figured. Sadly- I've read too many case studies were great pilots have flown themselves into the ground because they were just going by feel.

Same sorta thing- The butt dyno in the truck tends to be fairly inaccurate. Your proprioceptive feel reacts to lighting, outside environmentals, your hydration, rest, and nutrition. You need to have some sort of measurement (stopping distance would be the best) to back up your observation that you are stopping faster.

 

My Winterforce UV's are what help me stop better on ice

 

All very good points ^^^ and yes, that is the beauty of 4wd, pull the front of the truck in the direction you want to go.

Yes, if you are on slippery ice, nothing but chains will help...

This is my thoughts on this... The front brakes apply more force first. We all know this. This is evident in the fact that the front of the truck dips under hard braking. If you reach down and hit the E-brake(rear brakes) you will feel the back of the truck(or any vehicle for that matter) dip.

On a slippery surface in 2wd, when apply the brakes you will run into the front tires locked and the rear still turning. This is very evident in a automatic, as your rear wheels are still pushing you (until the point you press the brakes hard enough to lock the rear as well).

Now the same situation in 4wd... Your front and rear wheels are locked together. Therefore if you front wheels can't turn, neither can your rear.

So now on a slippery surface, when you apply your brakes, you are equally slowing the rotation of the front and rear wheels. This means you now have 4 wheels equally stopping you, and in a automatic you are no longer trying to overcome the push of the rear wheels.

I'm not saying it is always better to use 4wd. As someone else has said, you really want to have a loss of control, lock all 4 wheels at the same time on ice.

I use it mostly in packed snow parking lots. At slow speeds I can stop a whole lot quicker with all 4 wheels stopping me than the front two sliding and the rears pushing me into something like someones car.

 

+1

Or studded tires.

If you don't have either, not even FULL time 4x4 (locked front & rear) will have any effect on breaking on ice.

 

we were hit with a blizzard last week and all of the slide offs on the freeway I saw were SUV's, trucks, and Audis (AWD). Having 4wd gives you false confidence in slippery conditions if you arent careful. 4x4 or awd wont do anything as far as helping you stop faster. Its whether or not your tires have contact with the road.

I had a front wheel drive honda crx in college that i put snow tires with studs on every winter. I remember a guy in a full size ford trying to get up a snow packed road but couldnt do it. I drove around him and up the road and over the hill. Its all about traction and grip and if the power is getting to the road/ground, not necessarily if the engines output is reaching all four wheels or not.