Proper way to use 4 wheel high and auto

[campnowhere]

Hello! I have a 2019 Ram 1500 big horn and I live in Wisconsin with lots of snow during the winter and I was hoping to get proper clarification on appropriate 4 wheel drive usage.

I’ve read a lot that you can make turns in 4 wheel high just not sharp turns on dry pavement, is this true? Can I in fact make standard turns at stop signals when it’s raining or if there is snow on the ground?

And also, what is the general speed at which I can safely engage into 4 wheel high and 4 wheel auto & how fast can I drive while in those modes?

My main concern was freeway driving in rain and or snow at around 55-60mph. Is it safe to drive while in those modes during rain/snow and can I engage into those modes at those speeds?

I would appreciate any feedback I could get, thank you all for your time!

 

[dajogejr]

I often use 4 Auto when it’s raining.
I would use 4 High when there’s enough snow on the ground/slush that the front tires won’t grab like dry pavement.
**or dirt/gravel/grass/mud**
You don’t want to engage 4 auto or 4 high when the rear tires are spinning…

4 high on dry pavement tight turns is not advisable, it’ll bind up and you’ll feel it lurch and buck.
4 high in snow/dirt/mud/grass making tight turns is ok but the tires need to be able to slip a little.. so keep that in mind.
I wouldn’t advise it with just rain.
You can drive as fast as you want…but the question is, if you need 4WD…how fast isn’t safe?

 

[mikeru82]

4 Auto can be used at any time on any surface. It's basically the same as AWD. The wife and I keep our trucks in 4 Auto all winter and almost never use 4 Hi.

 

[firecadet613]

4 Auto can be used at any time on any surface. It's basically the same as AWD. The wife and I keep our trucks in 4 Auto all winter and almost never use 4 Hi.

This! I use 4 Auto when there's snow on the roads and keep 4 high for when I'm off pavement or full snow covered.

 

[Ramboy13]

Think of it this way -- 4 High means the front axle is "locked" in and the front tires will turn regardless. 4 Auto means the front tires only engage if/when slippage is sensed. So as others have said, you can run 4 Auto all the time, very safely. It'll be like running in 2 wheel drive until something slips, and then the front engages.
You only want to use 4 High when you're on some sort of surface that will allow the tires to slip (snow, sand, gravel, etc). Do not try to turn in 4 High unless the tires can slip.

 

[MarkTTU]

4 Auto can be used at any time on any surface. It's basically the same as AWD. The wife and I keep our trucks in 4 Auto all winter and almost never use 4 Hi.

I live in the Texas hill country and my 22 has probably spent the majority of its life in 4 Auto. I’ve found even on dry roads many of our intersections are such that AWD is much preferred for jumping out into traffic. We get some very oddly banked intersections and curves out here.

 

[HSKR R/T]

You can shift in and out of 4 auto and 4 high at any speed. The computer will basically tell you if you can't. And everyone else has basic covered everything else. I use 4-auto when I want to get the jump on someone from a light, or if it's icy. If I can get around in 2wd, then the truck stays in 2wd. I also use 4-high when drag racing, so I don't have to worry about wheel spin.

 

[Eighty]

For what it’s worth, my truck has spent 100% of its life in 4-auto (other than switching to actual 4WD). It’s a TRX and doesn’t even have 2WD-only mode. So I’m fairly confident in saying that 4-auto is fine all the time, even up to 118 mph.

 

[Dewey]

If there’s any snow or ice on the road I use 4 Auto. If the snow is very deep I put in 4 High. Great majority of the time 4 Auto is all that’s needed.

In rain I often put in 4 Auto if I need to accelerate fast from a stop but then go back to 2 WD for driving beyond that.

Basically in 4 High you want to avoid driving and especially turning on bare spots of the pavement. If you do you’ll feel it binding up. That’s for sure not good for the drivetrain.

 

[cerbo]

correct me if I'm wrong, 4 high will use more fuel and so will 4 auto as it turning extra drive components?

 

[dajogejr]

correct me if I'm wrong, 4 high will use more fuel and so will 4 auto as it turning extra drive components?

It will technically.
Any drag can impact fuel mileage.
But..it could also help. If you’re taking off and just spinning in 2WD..vs moving forward in 4A/4H.. you could argue getting up to speed more quickly and efficiently is saving gas vs. sitting and spinning.
My point is… negligible. If either 4A or 4H consumes 10 to 15% (just guesstimate with zero backing) more fuel, the safety of traction is worth it.
Could it be higher? Sure. End result in safety is the price to pay and I think we’re all willing.
I’ve left mine in 4A on highway trips when raining, and I couldn’t tell the difference in fuel mileage in the rain during 75 to 80MPH freeway rides.

I haven’t found myself in the position to use 4H at highway speeds…i.e., I don’t think, for me, in snow deep enough to warrant it.. that speed is safe.

 

[LouNY]

As has been said 4 auto can be used pretty much any time, 4 high it should be slick or greasy out. Depending upon the year of the vehicle 4 auto often engages the axle disconnect as soon as it is turned on then the computer controls and modulates the 4wd clutch pack as it thinks it needs to. So your mileage will suffer as the front axle is turning all the time. Much like looking the hubs on an older vehicle and leaving the transfer case in 2 wd. The axles are rotating but not being powered.

 

[Ready Go]

Much like looking the hubs on an older vehicle and leaving the transfer case in 2 wd. The axles are rotating but not being powered.

I love my modern Larry G/T and all the ease & comfort it gives, but sure wish I had my old K5 Blazer yet..many a good times in that thing!
Manually lock the hubs, run around on 2WD waiting for snow to fall, manually pull the 4WD handle, and have some fun!
Got an offer I couldn't refuse 30 years ago, and have been looking for another ever since..Jeeps have filled the void, but not the same.

 

[HSKR R/T]

It will technically.
Any drag can impact fuel mileage.
But..it could also help. If you’re taking off and just spinning in 2WD..vs moving forward in 4A/4H.. you could argue getting up to speed more quickly and efficiently is saving gas vs. sitting and spinning.
My point is… negligible. If either 4A or 4H consumes 10 to 15% (just guesstimate with zero backing) more fuel, the safety of traction is worth it.
Could it be higher? Sure. End result in safety is the price to pay and I think we’re all willing.
I’ve left mine in 4A on highway trips when raining, and I couldn’t tell the difference in fuel mileage in the rain during 75 to 80MPH freeway rides.

I haven’t found myself in the position to use 4H at highway speeds…i.e., I don’t think, for me, in snow deep enough to warrant it.. that speed is safe.

On my truck, when it was stock, there was a 1-1.5mpg difference on the highway between 2wd and 4auto.

 

[zlman]

I live in MN, 4auto for light snow covered roads, 4wd when iced or 4" and above of snow. Those are my personal guides and I've never been stuck yet. I've ran 70 mph in 4wd without issue.

 

[Threesuns1]

I love my modern Larry G/T and all the ease & comfort it gives, but sure wish I had my old K5 Blazer yet..many a good times in that thing!
Manually lock the hubs, run around on 2WD waiting for snow to fall, manually pull the 4WD handle, and have some fun!
Got an offer I couldn't refuse 30 years ago, and have been looking for another ever since..Jeeps have filled the void, but not the same.

Agree. When needed to order my 2000 F250 to get the locking hubs and manual transfer case. I want that control and peace of mind when it was/wasn't in 4wd. If they were calling for snow, I'd lock the hubs and only need to engage 4wd with the manual transfer shifter.

 

[Threesuns1]

Question? Does running 4 auto all the time cause more wear and tear on the drive train?

 

[LouNY]

Just a minor amount more, pieces are moving and getting power at times.

 

[HemiDude]

Just spent some time out playing in the snow that fell this morning. For most of the trip on the highway, 4wd auto was sufficient. There were a couple of times on two lane roads with drifting that I switched to 4hi, but it wasnt needed for long. 4auto is generally all you'll need.

PSA: If your vehicle only has 2wd and/or bad tires and/or you can't navigate in the snow, please stay off the roads. I saw far too many people on my trip today who's day was ruined because they weren't prepared for the conditions. FWD, AWD, 4WD all mean nothing if the driver isn't up to the task. Rant over, now let's go back outside and play!