2wd or 4wd on plowed roads

You don't say where you are from/driving -- so therefore determining the answer to your question is dependent in the over all condition of the road at any given time ---which only YOU can/should determine and your driving skills on slick/snowy/wet pavement. there is NO "correct answer" to your question -- just a bunch of "guesses".

 

I'm in Colorado. I'm not really looking for a correct answer, just feedback on when/how to make the decision on when to use or not use 4wd. It's my first 4wd so still learning and have primarily driven Subarus and AWD and part time 4wd are quite different.

 

I'll often use 4WD in a scenario like you described so long as I'm below highway speeds. I usually assume that if the road is slick enough for you to spin tires from standing start, it's also slick enough that you won't have any binding issues going around turns. If I hit a dry section, I'll disengage the front and flip it back on again once I hit snow.

I especially like to have 4WD on while going in a straight line. I'm often at higher RPM/higher torque while climbing hills around here and think the 4WD helps to prevent the rear of the truck from wandering.

 

Turning 4hi on/off while driving is fine, just remember do not try and engage 4wd if your tires are slipping. Wait until you have traction.

 

It's very simple. Turn on 4WD if you're coming up on snowy roads. If it's patchy snow, I often just leave it in 4WD, unless I am making some hard turns on dry pavement. Not that hard. All trucks operate this way (although the new F150's have 4WD auto).

By the way, 4WD in our trucks is "Part time 4WD." Vehicles like the Landcruiser and GX460, etc. come with Full Time 4WD.

 

With just 4wd power is still sent to the wheel(s) with least traction via the differentials. Trc and lsd help send power to the wheel with more traction, lsd being even more effective than trc, although Toyota doesn’t do a mechanical lsd, but via brakes and engine power. It’s also why you may need a differential lock in 4wd low.

 

Except auto LSD only works in 2wd. From the manual, "The system can be used on 2WD models and in 2WD mode on 4WD models."

 

There are a lot of terrible OPINIONS in this thread but I think you found your answer

 

Great -- you are a lot like we (wife and I) are the owner/drivers of the 17 4x4 taco and a 15 Subaru Outback. I sometimes wish the Taco had the best of both worlds where the AWD system is a no brainer -- this is great for my wife. She does not like to be bothered with knowing when to use the switch (or whatever) to put it in 4WD. I have had (and driven) 4wd's since my Father in law had one in the mid 80's. With time and experience -- trust me -- you will know when you need it. Out in Co -- you are lucky -- the snow is "usually a lot drier than here in the Mid-west and you many times get more to "practice" on. Till you get the hang of it -- take your time and go slower than you think you need to and increase your following distance!
Good luck!!

 

If you read this thread, the opinion seems to be that Tracoff in 4wd hi is sort of equivalent to lsd and should have been named differently.

https://www.tacomaworld.com/threads/a-trac-trac-auto-lsd-explained-easy-to-understand-i-hope.70551/

 

Thanks for the link. Good info but I'll need to read it a few time to fully make sense of it.

So what is a-trac? Is that an old version of crawl control or something? I don't see any a-trac button next to my cigarette lighter (which I also don't have)

 

It's in that link lol.

 

If I'm slipping I use 4x4. If I'm not I'm in 2hi.

So apply that.
If they've plowed and it's no longer snowing 2hi.

If they're plowing and it's still snowing and you're slipping turn to 4hi. Just go easy on cornering.

 

I’m still waiting for my truck which is on order ( lol ) so don’t know all the buttons yet, but my understanding is that it’s on unless you hit the trc off button. Yes that thread explains it but basically it’s an lsd on steroids providing traction if there’s slippage. It’s independent of crawl mode.

 

I know. But it's described similar to how I understand traction control and/or crawl control and I don't think I have a-trac so was asking for clarification. Is it an older tech and replaced or tech on other vehicles but not the tacoma (or at least mine)? Or is it for manual trans? I have a locking dif button is the spot shown for a-trac in my manual.

 

You have a-Trac but if there isn’t a button it’s on by default just like trac and that makes more sense intuitively in that it works the same way to disable in hi or Lo.

Edit: manual speaks of the a-trac button, but that’s apparently only for manual transmissions. Toyota didn’t make all this combinatorial explosion easy to understand!

Actually phdog, you may be correct for the trdor - good line of inquiry! I stand corrected - apparently what I said applies to non trdors.

https://www.tacomaworld.com/threads...2016-4x4-models-non-trd-offroad.437814/page-9

 

Not that I know what I'm talking about but I jotted notes the other day to clear up my own confusion about the various safety/driving aids. I might be incorrect in my understanding. "Auto on" or "default" means it's enabled when you start the car.
*Note: I have an '18 TRD OR 6MT so Crawl Control and MTS aren't in my notes.

2018 Safety Aids:
- Pre-Collision System (PCS): Auto on, have to adjust through dash menu
- Lane Departure Alert (LDA): Must turn on w/steering wheel button, active >32mph
- Dynamic Radar Cruise Control: Default mode, disable by holding cruise on/off for 2 sec, adjust distance w/steering wheel button
- Intuitive Parking Assist (sonar): Toggle on/off, setting persists
- Blind Spot Monitor/Rear Cross Traffic Alert (in reverse only): Toggle on/off, setting persists

Driving Aids:
- Auto LSD: Auto off, use only in 2WD, uses brakes as electronic LSD, shouldn't use full-time, turning this on disables VSC/TRAC (until you hit a faster speed)
- Rear Diff: Avail in 4L, locks left and right rear wheels to same speed, the last-resort option when you need traction
- A-TRAC (6MT only): Avail in 4L, uses brakes as electronic LSD
- VSC/TRAC: Auto on, pulses brakes to avoid wheel slipping (sideways, straight line slipping doesn't seem to engage it much for me), disable by turning on Auto LSD

So far the only thing I've messed with is going between 2H and 4H depending on the road conditions.

 

What’s the fastest you can go in 4hi? I was driving on snow highway around 60 mph in 4hi. Is that bad?

 

Nope. You can go as fast as you want. The speed limitations are for taking the truck in or out of 4hi.

 

This is how I think, too. Which is why I couldn't understand why the 4WD system on a rental Jeep Cherokee I drove would only turn on automatically right when you lost traction. I think it clunked into 4WD a couple times... seems like a terrible idea for longevity.