Q: So Snow Mode is for Snow/Ice Conditions, but What if on the Highway?

[Expedition Dave]

Q: So Snow Mode is for Snow/Ice Conditions, but What if on the Highway?

I get that the system is set up for what I would assume: slow going through bad weather--to get you through it.

But if you are traveling with traffic at highway speeds, and there are some snowy, icy bits what mode would you all recommend?

Not a trick question, but I am curious the hive's thoughts and please state why. Please refrain from long talks about safety, snow tires and chains b/c obviously, one must drive the conditions, but curious the opinions here. And also b/c most people who don't live in the snow belt, but drive through it briefly, usually don't run snows but all seasons/ATs (like me lol).

My thoughts that a locked center diff and/or locked rear (unless going through the thicker, less than 10 mph stuff) on the highway or carrying any real speed might cause the vehicle to go into a skid/slide more readily since spinning tires offer no traction, but a tire rolling along will offer some directional stability.

So, I personally feel that AWD and traction control are the way to go, either in SNOW mode or ECO mode to soften throttle inputs.

 

[Mlarv]

First off snow mode is for snowy and icy roads. If you are on a highway going highway speeds I would hope it is not snow and ice. It helps you get going not stopping.

I use snow and ice mode when traveling at highway speeds some times, because to get to the highway I have to travel some backroads that had not been cleared. I will just leave it in what ever mode it is in when I hit the highway. When I got off the highway I most of the time I am back on back roads.

If I knew I would not hit back roads or snowy icy roads again I would turn it off.

 

[wakeboarder]

The manual is a good baseline to start with to help determine how Ford thinks they should be used.

 

[carymccarr]

If you’re going “highway speeds” then obviously the rear diff shouldn’t be locked.

But frankly if you’re going “highway speeds” and the conditions are deep snow that warrant a locked diff or deep snow/mud ruts setting (nav) that’s a whole different discussion.

 

[Expedition Dave]

Exactly what I thought. Thank you. No magic fairy unicorn dust here.

 

[shane_th_ee]

But if you are traveling with traffic at highway speeds, and there are some snowy, icy bits what mode would you all recommend?

The conditions you describe here are the exact conditions that prompted the development of 4A systems. Traditional 4x4 systems had two problems in these conditions; first, on the "dry" sections of pavement the driveline would have a tendency to bind in the turns. Second, on the snowy/icy patches, a throttle impulse can cause a spin out as the torque "steer" on each axle is in the opposite direction which results in a rotational force around the center of the vehicle. 4A systems solved both of these problems by 1) allowing the front and rear drive shafts to rotate at different speeds and 2) reducing torque when wheel spin is detected. Stability control systems built on this foundation by adding yaw sensors, steering input sensors, etc, etc.

In summary: Snow mode for compact snow and ice, 4A for roads with patches of clear and snowy/icy.

 

[Fizzy]

This is a moot point. As per the manual:

The locker mode may automatically disengage based on certain conditions such as vehicle speed. When engaged, a telltale in the instrument cluster will illuminate amber and the switch button will be illuminated. When the speed is exceeded the telltale will turn gray, the locker will be disengaged and be in standby mode until the speed conditions are met.

The locker disengages at city speeds, let alone highway speeds.

As for experience - up here we spend 6 months of the year driving on deep or packed snow and black ice. On the highway it's either in 4A+Normal or Snow mode, depending on whether it's full coverage on the highway, or patchy.

 

[Meeker]

This is a moot point. As per the manual:


The locker disengages at city speeds, let alone highway speeds.

As for experience - up here we spend 6 months of the year driving on deep or packed snow and black ice. On the highway it's either in 4A+Normal or Snow mode, depending on whether it's full coverage on the highway, or patchy.

I'm going to be the dissenter here - for any highway driving in the winter, I will switch to Normal or Eco and 2WD. AWD in my opinion, even though it frees up the wheels, still adds resistance to your front wheels. The most traction you can get for steering is freewheeling front wheels. It's not a big thing - if I have any notions of getting off the highway I'll leave it in Snow mode. But to me, on the highway you only care about stopping and steering, so maximize your traction for those parameters by driving only 1 wheel...

 

[Fizzy]

I'm going to be the dissenter here - for any highway driving in the winter, I will switch to Normal or Eco and 2WD. AWD in my opinion, even though it frees up the wheels, still adds resistance to your front wheels. The most traction you can get for steering is freewheeling front wheels. It's not a big thing - if I have any notions of getting off the highway I'll leave it in Snow mode. But to me, on the highway you only care about stopping and steering, so maximize your traction for those parameters by driving only 1 wheel...

I think it was you I passed in the ditch on Highway 1 last week??

 

[carymccarr]

I'm going to be the dissenter here - for any highway driving in the winter, I will switch to Normal or Eco and 2WD. AWD in my opinion, even though it frees up the wheels, still adds resistance to your front wheels. The most traction you can get for steering is freewheeling front wheels. It's not a big thing - if I have any notions of getting off the highway I'll leave it in Snow mode. But to me, on the highway you only care about stopping and steering, so maximize your traction for those parameters by driving only 1 wheel...

On a snow covered highway while it’s snowing you’re in 2wd? I’m not going to argue because you’re in Canada but I’m pretty far north in the US and drive all the time through snowstorms and there’s no way I’d keep it in 2. I do it every now and again (of the road is empty) to see how it behaves but it’s spooky.

 

[MxRacer965]

On a snow covered highway while it’s snowing you’re in 2wd? I’m not going to argue because you’re in Canada but I’m pretty far north in the US and drive all the time through snowstorms and there’s no way I’d keep it in 2. I do it every now and again (of the road is empty) to see how it behaves but it’s spooky.

But when he ends up in whatever Canadians call a ditch he always has the mount-me’s and moose to call to help him out. So all is good.

 

[Fizzy]

But when he ends up in whatever Canadians call a ditch he always has the mount-me’s and moose to call to help him out. So all is good.

I live in the same city, and trust me, nobody else doing a decent clip on the highway is running in 2wd if they have the option of 4wd.

Less grip and steering in 4wd! Someone should let the World Rally Cross know they’ve got it all wrong.

 

[Meeker]

I live in the same city, and trust me, nobody else doing a decent clip on the highway is running in 2wd if they have the option of 4wd.

Less grip and steering in 4wd! Someone should let the World Rally Cross know they’ve got it all wrong.

I tried to be very specific about what I meant - the "grip" I'm talking about is braking and steering grip only. No question AWD gives you better traction for acceleration. But I'd love to hear your take on how AWD improves braking and steering at highway speeds.

If you guys are mashing the accelerator on snow-covered highways then...

As for World Rally Cross, that's a much different type of driving. They drift through every corner so 4x4 is better for them. Are you doing that on the highway?

Here's the rationale for what I'm talking about: https://www.engineeringtoolbox.com/friction-coefficients-d_778.html

If you let your front wheels spin freely, they are more likely to be in static friction since the engine isn't trying to break them free. Think of it this way - in any turn, you have the sideways force on the tire trying to break it free, plus any powered wheel ALSO has engine torque trying to break it free. Unpowered wheels will almost always stick to the road longer than powered wheels. So unless you're rally driving on the Trans Canada to Lake Louise 2WD has a better chance of keeping you on the road.

To the best of my knowledge nobody has ever tested this. Lots of tests about accelerating and braking, none about turning at highway speeds. Please let me know if I'm mistaken.

EDIT: What do you know, found supporting articles right after posting: https://www.popularmechanics.com/cars/a3091/the-myth-of-the-all-powerful-all-wheel-drive-15202862/
https://www.wheels.ca/news/does-all-wheel-drive-actually-help-in-winter-driving/

 

[Expedition Dave]

Meeker, I feel there is a great deal of truth to what you are saying, and maybe at highway speeds the AWD vs 2WD is moot. My feelings is that AWD is still the right answer, but I can definitely see where if one goes over a patch of whatever, it might even depend on if it hits all the wheels or just one side.

My vision is that as one wheel slips, the system reduces power by sending power elsewhere, helping to keep things tracking forward rather than inducing much yaw. 4wd would actually be better at this as AWD systems do hesitate a bit.

Either way, for this trip in potential patchy conditions a have moved from 2wd, to AWD Normal/Eco, to snowy AWD.

 

[carymccarr]

I tried to be very specific about what I meant - the "grip" I'm talking about is braking and steering grip only. No question AWD gives you better traction for acceleration. But I'd love to hear your take on how AWD improves braking and steering at highway speeds.

If you guys are mashing the accelerator on snow-covered highways then...

As for World Rally Cross, that's a much different type of driving. They drift through every corner so 4x4 is better for them. Are you doing that on the highway?

Here's the rationale for what I'm talking about: https://www.engineeringtoolbox.com/friction-coefficients-d_778.html

If you let your front wheels spin freely, they are more likely to be in static friction since the engine isn't trying to break them free. Think of it this way - in any turn, you have the sideways force on the tire trying to break it free, plus any powered wheel ALSO has engine torque trying to break it free. Unpowered wheels will almost always stick to the road longer than powered wheels. So unless you're rally driving on the Trans Canada to Lake Louise 2WD has a better chance of keeping you on the road.

To the best of my knowledge nobody has ever tested this. Lots of tests about accelerating and braking, none about turning at highway speeds. Please let me know if I'm mistaken.

EDIT: What do you know, found supporting articles right after posting: https://www.popularmechanics.com/cars/a3091/the-myth-of-the-all-powerful-all-wheel-drive-15202862/
https://www.wheels.ca/news/does-all-wheel-drive-actually-help-in-winter-driving/

You’re of course right from a physics standpoint but I’ve driven, like you, in snow for my entire driving life. I’ve had rear wheel, front wheel, AWD and 4WD. Although you’re technically and academically correct about free wheel friction all of those calculations go out the window when you’re in snow (true snow not patchy or hard pack) using rear wheel drive and the back end gets away from you, the front tires lose traction or you start to slide. ESPECIALLY with the crazy flintstones car width tires these things have that easily start to float over the snow.

I’ve had PLENTY of times on roads where I’ve needed the power of the front wheels to pull/nudge me back into the lane or gain control/alignment of the back end sliding away from me. Even more so on secondary or windy roads.

Im not going to argue about braking etc etc..I believe the best way to slow yourself down and remain in most control is by gently applied braking not engine/transmission braking as some here do.

For all that’s holy and sacred, if there is anyone here from the south about to take a trip to snow country and are considering how to drive though a storm...put it in 4wd and take it slow. Physics experiments are a good way to ruin your vacation and make you wish you took the extra rental insurance.


Sent from my iPhone using Tapatalk

 

[Fizzy]

To the best of my knowledge nobody has ever tested this. Lots of tests about accelerating and braking, none about turning at highway speeds. Please let me know if I'm mistaken.

EDIT: What do you know, found supporting articles right after posting: https://www.popularmechanics.com/cars/a3091/the-myth-of-the-all-powerful-all-wheel-drive-15202862/
https://www.wheels.ca/news/does-all-wheel-drive-actually-help-in-winter-driving/

Both of these articles are extolling awd+all season versus 2wd+snow tires.

I’m saying neither. Awd+snow tires (real snow tires). Best of both worlds.

Furthermore, both articles are opinion pieces. The opinion of individual people. Opinions are not facts.

 

[Phillip White]

During the winter months here in Saskatchewan Canada I am either in Snow mode or Sport mode. Snow mode if the plows have not come through yet and Sport after they have. Both of these modes offer me a vehicle response I need to feel comfortable on these roads.
I also use All Season tires as Winter tires sold here bring your wheel size down way to low for my liking and have never found Winter tires any better for grip than good All Season.

 

[KSC 2019 XLT]

This is a moot point. As per the manual:


The locker disengages at city speeds, let alone highway speeds.

As for experience - up here we spend 6 months of the year driving on deep or packed snow and black ice. On the highway it's either in 4A+Normal or Snow mode, depending on whether it's full coverage on the highway, or patchy.

What is "locker"? Serious question. I have a 2019 Expy XLT 4WD (non FX4) and don't remember seeing the term locker in the owners manual. Apologies if dumb question.

 

[Fizzy]

What is "locker"? Serious question. I have a 2019 Expy XLT 4WD (non FX4) and don't remember seeing the term locker in the owners manual. Apologies if dumb question.

Differential Lock. I believe it comes on the HD Tow package, or FX4 package. It’s an extra button down by the mode selector, next to the 2A and 4A buttons.

Manual reference here.

 

[Fizzy]

I also use All Season tires as Winter tires sold here bring your wheel size down way to low for my liking and have never found Winter tires any better for grip than good All Season.

Watch any video comparing them. Half the stopping distance. Twice the acceleration grip. Not to mention that all-season rubber compound gets stiff around 0c, and in your prairie winters at -30c and below, they’re hockey pucks. Winter tire compounds are formulated to stay soft down to those temperatures.