2wd or 4wd on plowed roads

I can't seem to find a good answer to this. I'm new to owning a 4wd but everything I've read says don't use 4wd on dry roads.

Well, we had some snow (finally) and while the roads weren't dry they were plowed with a mix of dry spots, slush and some snow packed sections. I didn't really need 4wd but seems to go better from a stop (no spinning).

I guess what I'm curious about is if 4wd needs some slippage on the surface, what happens when cornering? Am I losing traction while something slips? Doesn't seem ideal so better to use 2wd in these types of conditions?

 

I turned on auto LSD(in 2WD) in the last mixed driving scenario like you said and mine did fine.

 

If you are not slipping all over the place you don’t need 4wd. But just remember if you are in 4wd you can go fast but not stop.

 

This is where part-time AWD beats 4x4. The manual says use 2wd on dry pavement but you will be told that you can use 4x4 on straight sections. You will feel binding in the steering as you turn on dry pavement in 4wd...not good as wheels are spinning at different speeds.

 

If you feel safer in 4x4 always use it. Rare to see tcase problems on Tacomas.

I usually use the rule that if you can see pavement use 2WD, but Americans are having one hell of a winter, and not many have snow tires sold in their states haha.

 

Pretty hard to answer questions like this on the internet. The answer is yes and no. Where I live we get a lot of blowing snow on days it isn’t snowing. Depending on the conditions of the day I will sometimes turn 4wd on and off many times on my trip. On perfectly dry roads that are straight but have drifting I will run 4wd. 4wd will help keep things from stepping sideways when hitting the drifts. Drifts are NEVER straight and even when you hit them it can pitch you sideways. That said if I know the road ahead has no drifting I will take it out of 4wd. Basically you need to be in 4wd before you hit the drifts.

If I am in the city I don’t run 4wd unless there are totally snow covered roads. There is too much turning and lane changing which on dry roads abuses the drivetrain too much. That said I run full winter snow tires so I have that to aid in traction and stopping. So unless I need it I leave it off in the city.

So there is the unclear answer. It is an experience thing and not something one can answer on the internet in terms of do this or do that.

 

Doesn't the taco have traction control as well? When I do get slipping I can hear it kick in and the light on the dash flashes. I've never messed with it. Seems to work, 4wd works better.

As I understand it, you can't drive around all day with auto LSD turned on and I think it even cuts back off once you hit a certain speed. From the manual "When the AUTO LSD system is turned on, the VSC and TRAC systems will turn on automatically if vehicle speed increases." To be honest, I've never really understood the point of turning VSC and TRAC off unless you are stuck.

 

That's why I've been playing around with it. In 4wd today, things seemed to work fine. Never felt any binding nor any noticeable slipping. Of course, this was in town at slower speeds. Not sure how it would behave on mixed condition freeway. Times like this I miss my Subaru.

 

Auto LSD will be on remain on below 30mph. Once you’re faster than that Trac turns back on and the vehicle has full control of all stability control functions again. Once you decelerate below 30mph Trac turns back off as long as you haven’t selected the switch again or turned the truck off.

Staying in 4hi in those conditions won’t hurt your truck unless the road is really 100% clear of snow and ice. Normal turns encountered while driving, turning and lane changes will not bind up the system but you will generally want to go back to 2hi when cranking the wheel around, such as when you’re parking.

 

If I'm slipping on snow plowed roads I turn on 4wd. Obviously I turn it on if I know the road is pretty much going straight for a while then turn it off if I know i will be taking a bunch of turns.

 

It only takes a few days to figure it out. I also will engage and disengage 4HI many times on a short trip on roads you are describing.

 

I was doing that, on-off-on..., but thought maybe I was doing it wrong. Leave it on or leave it off. Good to know switching back and forth is okay.

 

My residential streets are often still covered with a thin layer of snow after They are plowed. I run in 4 hi through town so that I don't have to worry about pulling out in to traffic. Once I hit the highway, I go back to 2wd if conditions allow me to go normal speed (or close to it). If the highway conditions are bad enough to stay around 50 or below...it stays in 4 hi. Often, when I hit the off ramp, there is an icy patch at the end and I kick it back in to 4 hi so that I can safely make the turn and get going on the cross street.

So yeah, kind of just need to jeep any eye out and make the decision. You'll get a feel for what conditions have too much traction and will cause binding. It will be harder to steer.

 

If the roads are wet and slippery, you should be fine in 4X4. I'd imagine that if you were plowing the roads, they should be slippery enough.

If you feel the truck binding (especially when turning), you probably need to turn 4X4 off.

I thought this was a decent video when I saw it.....

 

This was my first 4x4 vehicle as well and I learned what driveline binding was first-hand. Terrifying way to learn to not use 4x4 on pavement.

Plowed roads are really a toss up but if you can see enough of the pavement under the snow then you'll be fine without 4WD. I have only had to engage it when on roads completely caked with snow or slush. It mostly helps with accelerating from a complete stop.

 

Use 4X4 sparingly and only as needed. It only takes a second to flip the switch. Generally you only need it, even on unplowed roads, to get moving and up inclines. Once moving, and if road conditions allow you to safely drive over 25-30 mph you don't need 4X4. In fact using it in those conditions does more harm than good. Not only to the drive train, but it can cause you to spin out. 4X4 is not AWD and they work very different. AWD is the much better option for icy and snow covered roads, but 4X4 is a much better option for off road conditions and used carefully is a huge asset in snow and ice.

 

I use it whenever I feel roads are slippery enough to where I can' get going at normal pace from a red light in 2wd. To get the bind you have to have the wheel turned quite a bit. Manual even says to turn on the 4wd system every so often to keep it in good running order. In summer I will run 4wd for 10 min every month in town where I'm not making 90 degree turns. You can feel slight binding even in snow covered parking lots going slowly and having the wheels turned all the way to one side.

 

We had a good ice over last week and I had to go to work. I pretty much left it in 4HI the whole trip in. I think that if you are in slippery conditions, you're OK to just stay in 4HI... if it gets to be dry pavement, then shut it off.

Edit to add: I have to take a sharp turn to get in my driveway, so I turned it off for that.

 

I had a 2000 4Runner without vsc, trac. I had 2 accidents over ice in 2wd ( the 2nd one my brother having borrowed it ) the 2nd one totaling it at 186kmiles. While you can’t do much over ice, I think traction and stability control help a lot in recovery in a skid even more than 4wd, although no doubt 4wd will help. I had told myself that my next vehicle has to be AWD, but I just couldn’t bring myself to go for a ridgeline over the trdor, but newer vehicles having trc, vsc really make it safer.

This video is great explaining the benefits of vsc and Trac:

https://youtu.be/Z8KjsjrIGqI

 

So I get the sense that 4wd is better anytime the road surface is slippery and that you might need to turn off and on as needed in variable conditions.

I'm also not sure the point of auto LSD. If the road is slippery enough that in 2wd you have a wheel spinning might as well just use 4wd. Also, doesn't traction control more or less do the same thing? I've certainly had the rear wheels spinning some like when accelerating from a stop on snow packed roads but traction control seems to kick in then. What's the point of auto LSD? I guess traction control can cut power and maybe LSD doesn't but still doesn't seem all that useful.