4A vs 4H Snow driving

[fordtruckman2003]

First truck with 4A so it sounds like it will be an interesting time when I see some snow.

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[gtotco]

I live in CO and have snow tires (Bridgestone Blizzack) and use 4A in the snow 99% of the time. I only use 4H getting up our driveway to our mountain house which has a steep 90 degree turn and sometimes snow up to 8 or 10”.

like most things with 4wd/awe the benefits are low speed for the extra traction with 4H - I only use it to get unstuck. If I’m on a road surface fast enough to drive over 15-20mph its tires that are going to make the real difference. In a truck 4A still better than 2H because of the lack of rear weight but otherwise it’s all mostly the same.

Getting unstuck though 4H in the deep snow mode is great. You can get all 4 tires spinning so one of them can grab. Also I like it going around our sharp bend because I can get the rear to kick out a little bit which is helpful if the snow banks start to close in and the turn gets tighter because I can get it around a little bit faster with rear traction spinning a bit. Guessing that is not what most people are looking for though…

Also btw having lived in Western Pa (went to school in Pittsburgh) I would likely just get some decent all season tires with winter rating (maybe Michelin crossclimate - I use defenders in summer and love them) and keep chains since it’s so rare that you really need snow tires but when you do it’s a lot of steep hills. I keep a set in my truck and with true snow tires and used to use them all the time when I had Wrangler Duratracs (winter rated) on and could not make it up the driveway in heavy snow. They worked fine on the highway though (other than the fact that they make highway driving torturous due to noise and handling) and most people here seem to get along just fine with an all season or AT tire. As long the roads are mostly clear they will work other than when it gets icy and there chains will get you through anything.

 

[DEEPDOWN]

4h puts the truck into a position where the front wheels rotate ever so slightly more per given distance due the rolling diameter being slightly smaller because of the additional mass on them. Functionally they're almost like slightly smaller tires due to sidewall deflection. That mass = the pace setter so the rear wheels can slip ever so slightly. Weighting the bed can balance it out making for a much better balance / response. If you don't use the bed to carry anything, dropping 3 psi or so can balance it out better. You can gauge this on nice flat ground by measuring the distance between the ground and the rim.

That’s not why the front rotate more; rolling diameter is virtually the same, but the front wheels (particularly the outside wheel will try to rotate considerably faster when cornering). The front outside wheel when making a hard lock turn, will try to turn possibly as much a twice as many rotations as the rear. With no differential action available between front and rear axles (4H/4L), the driveline will lock on dry pavement as slipping can only occur through road conditions (ice/snow/loose gravel etc). For this reason 4H/4L should NEVER be used on dry roads (although technically would be ok if ONLY driving in a straight line ?).

 

[Je1279]

Earlier this week was my first experience with the truck in the snow. My old truck had 4A and the new truck does not. I was a bit concerned about the slushy road situation where I would have used 4A in the past. I engaged slippery mode and had no issues during the ride home. Only one data point, but I'm happy that 4H worked well in that situation. For what its worth, I do have all terrain three-peak mountain snowflake rated tires.

 

[pavementends]

All Slippery Mode does is engage 4WD and reduce throttle sensitivity, just like Eco Mode does.

Deep Snow mode engages 4WD, rear locker, disables traction control, and increases throttle sensitivity and shifts at higher RPM, just like Sport Mode does.

Think of the drive modes as a shortcut to activate multiple features with one "button". It's not like the drive modes activate some other functions that aren't already available through multiple button pushes.

 

[JIMFOUNTAIN]

So what else does Slippery or Snow (whatever it is) mode do, other than switching to 4A?

4A where available otherwise 4H then 2H. Throttle tip in. Shift points. In a PB the available regen is reduced to avoid light braking being only rear wheels (like in 2H Normal or Tow or Eco). Traction control on but seems more forgiving.

 

[mdn14]

All Slippery Mode does is engage 4WD and reduce throttle sensitivity, just like Eco Mode does.

Deep Snow mode engages 4WD, rear locker, disables traction control, and increases throttle sensitivity and shifts at higher RPM, just like Sport Mode does.

Think of the drive modes as a shortcut to activate multiple features with one "button". It's not like the drive modes activate some other functions that aren't already available through multiple button pushes.

Besides throttle sensitivity, and transmission shifting strategies to name a few...

 

[pavementends]

Besides throttle sensitivity, and transmission shifting strategies to name a few...

Still, shortcuts vs turning dial to Eco Mode then hitting 4WD button (same as Slippery Mode)

Deep Snow is a shortcut vs turning dial to Sport Mode, hitting 4WD and locker and disable traction control buttons...

You can get to the same "modes" either way

 

[JBMCEQY]

I only have 4H and it's been amazing in the snow. I do wish that I had 4A because it's a bit of a chore to switch in and out of 4H and 2H when it's patchy

However, as for the stock Pirelli ATR tires, I am not impressed with their performance in the snow. If I only had 2H I'd have zero confidence with those on the snow/ice.

 

[bgalakazam]

Drove in unclean roads today, sub 0. 4A was slipping now and then, 4H not so much. Both in Slippery mode with stock tires.

I love 4A for wet and rain, but on snow it hasn't done much for me. Luckily, it's easy back and forth 4A to 4H. Roads are usually salted and clean in Germany, except the residential areas and during storms.

 

[WalterMitty]

Still, shortcuts vs turning dial to Eco Mode then hitting 4WD button (same as Slippery Mode)

Deep Snow is a shortcut vs turning dial to Sport Mode, hitting 4WD and locker and disable traction control buttons...

You can get to the same "modes" either way

I think hitting with the Modes is way to go....quick cheat code on getting to the setting one may want, and you can always customize from there. I like to hit Sport Mode, and then put it back in 2H and turn traction control ALL the way off when feeling like a hooligan.


IMHO: When to use 4A vs 4H

4A: Rainy and/or intermittently slippery conditions.

4H: Conditions are "known" and consistent. Like, 4 inches of snow everywhere.

But again, I think the modes are just a better way to get you to a good place and faster/easier to deal with.

 

[DBL R]

I think hitting with the Modes is way to go....quick cheat code on getting to the setting one may want, and you can always customize from there. I like to hit Sport Mode, and then put it back in 2H and turn traction control ALL the way off when feeling like a hooligan.


IMHO: When to use 4A vs 4H

4A: Rainy and/or intermittently slippery conditions.

4H: Conditions are "known" and consistent. Like, 4 inches of snow everywhere.

But again, I think the modes are just a better way to get you to a good place and faster/easier to deal with.

this. 4A works well for variable road conditions or low speed turning to reduce binding. 4H works well when the road surface is constant. Slippery is nice for PB since it reduced regen braking and focuses more on the mechanical brakes for abs. Also helps to reduce/slow throttle input to reduce tq, the instant torque of the electric motor is significant during inclement weather. I also turn traction control off 1 click. Fords traction management is too aggressive and often gets me into trouble rather than saving me from it.

 

[HammaMan]

That’s not why the front rotate more; rolling diameter is virtually the same, but the front wheels (particularly the outside wheel will try to rotate considerably faster when cornering). The front outside wheel when making a hard lock turn, will try to turn possibly as much a twice as many rotations as the rear. With no differential action available between front and rear axles (4H/4L), the driveline will lock on dry pavement as slipping can only occur through road conditions (ice/snow/loose gravel etc). For this reason 4H/4L should NEVER be used on dry roads (although technically would be ok if ONLY driving in a straight line ?).

Both are true. Ask anyone running same tire pressures front and rear to engage 4h (ESOF, not TOD) and ask them if it's growling running perfectly straight. Yes, yes it is.

 

[goalieThreeOne]

4A and slippery mode.

 

[scott011422]

The way i've seen it is for me, 4A is like AWD. If the roads are ok with icy spots, 4a is where its at. Wheeling, mud or snow covered roads with no pavement showing it doesn't work well on. For these things 4H is far superior.

Everything I needed 4H for on my 05' f150 is the same things I need 4H for on my 22'. If you think that you might need 4WD, Thats where the 4A is nice.

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