2 or Auto

Brian S. · January 13, 2017

Funny read, good arguments but I have both a Subaru (2 vehicles) and this truck. Sadly, I must say it is not the same as Subaru's AWD. Symmetrical, 4 wheels spinning evenly at the same time. in "auto" on the truck, it only engages when it loses traction does it not? So stop comparing all-the-time AWD with auto already.

Any case, to OPs original question, yes drive it as fast as you want.

This.

The larger point here is that we all (4X4 GM owners) have a 4wd system that we can leave on all winter and only lose a mile or two per gallon, while gaining safety for ourselves and our families.

A 4wd system we can use at a boat ramp on vacation and drive home on the freeway and not have to wonder if we destroyed the transmission.

A 4wd system that engages seamlessly when our rear wheels slip if we hit an icy patch on the road

THAT is the issue, not if it's the same as a soccer mom Subaru. (nothing against Subarus, handy in the snow, but we're all full size truck drivers who likely don't consider a Subaru a substitute)

As far as I know, no other full size truck brand offers this and there is no more important feature if you live in a region that gets snow.

I make it a point to buy American, but if Toyota was the only brand selling this there would be a Tundra in the garage. The other differences between the truck brands are irrelevant.

truckguy82 · January 13, 2017

As far as I know, no other full size truck brand offers this and there is no more important feature if you live in a region that gets snow.

.

Ford has it, i believe they started using it in 2011, the new raptor actually has an "awd" labeled setting on it.

The system in our gm works very well, not sure if the ford has any downsides

Silverado Steve · January 13, 2017

My friend has a 2016 F-150 Lariat, it has 4 Auto.

Brian S. · January 13, 2017

My friend has a 2016 F-150 Lariat, it has 4 Auto.

Other brands have it, but it's optional, n ot on most models.

ALL GM have it.

When I looked at Ferd in 2010, only the HD model had it.

Silverado Steve · January 13, 2017

That is true, i think you have to get the Lariat on up to get that fun tion. The XLT does not come with it as standard. Up until this MY the new Colorado didnt come with the auto function either.

Other brands have it, but it's optional, n ot on most models.

ALL GM have it.

When I looked at Ferd in 2010, only the HD model had it.

Knotsure · January 13, 2017

This.

The larger point here is that we all (4X4 GM owners) have a 4wd system that we can leave on all winter and only lose a mile or two per gallon, while gaining safety for ourselves and our families.

A 4wd system we can use at a boat ramp on vacation and drive home on the freeway and not have to wonder if we destroyed the transmission.

A 4wd system that engages seamlessly when our rear wheels slip if we hit an icy patch on the road

THAT is the issue, not if it's the same as a soccer mom Subaru. (nothing against Subarus, handy in the snow, but we're all full size truck drivers who likely don't consider a Subaru a substitute)

As far as I know, no other full size truck brand offers this and there is no more important feature if you live in a region that gets snow.

I make it a point to buy American, but if Toyota was the only brand selling this there would be a Tundra in the garage. The other differences between the truck brands are irrelevant.

Well said![emoji1376][emoji1376][emoji1376][emoji1376][emoji1376][emoji1376]

I won't even look at ford dodge or Toyota since I bought my first GM full size 4wd. I have recently looked at those manufacturers to see if they offer auto 4 but the models that do have that option are usually out of my affordable price range. I didn't buy a base work truck silverado 4x4,I do have an LT with some decent options. It is by no means a high trim level but it has my beloved auto 4. I used it this morning in a little drizzle here in Austin . It hasn't really rained lately and the roads were unusually slippery. I love it. And will continue to use it. Have a great Friday everyone.

2014 Chevy silverado Z71 DCSB w/Bilstein 5100 leveled front end

JeremyW426 · January 13, 2017

EXACTLY! This is exactly why I consider why 4auto very similar to awd.

4auto uses 3 differentials, front, rear, and center

4hi only has 2 because it locks the center

When we switch to 4auto, we are engaging the center differential

When we switch to 4hi, we lock the center differential, making it no longer a "differential"

I sort of want to see a video of you going to your local dealership and trying to order parts for your center differential. Simply for the look on their faces when you suggest there is in fact what is called a center diff on these trucks. Its a transfer case, for a 4WD system, all be it an advanced one, but still 4WD none the less.

Brian S. · January 13, 2017

Well said![emoji1376][emoji1376][emoji1376][emoji1376][emoji1376][emoji1376]

I won't even look at ford dodge or Toyota since I bought my first GM full size 4wd. I have recently looked at those manufacturers to see if they offer auto 4 but the models that do have that option are usually out of my affordable price range. I didn't buy a base work truck silverado 4x4,I do have an LT with some decent options. It is by no means a high trim level but it has my beloved auto 4. I used it this morning in a little drizzle here in Austin . It hasn't really rained lately and the roads were unusually slippery. I love it. And will continue to use it. Have a great Friday everyone.

2014 Chevy silverado Z71 DCSB w/Bilstein 5100 leveled front end

I've got a bunch of nice options in the current truck like heated power seats, spray in liner with lo-pro tonneau, step tubes, park assist, navigation, the bigger screen infotainment, console, sliding rear window, undercoating, etc- but would trade ALL that crap for the auto 4wd.

It is the only deal maker/breaker for me in trucks and until other makers realize this they won't get my business.

BTW- usually I buy like you- LT with All Star pack. Best value on the road and has everything I really want!

TJay74 · January 13, 2017

EXACTLY! This is exactly why I consider why 4auto very similar to awd.

4auto uses 3 differentials, front, rear, and center

4hi only has 2 because it locks the center

When we switch to 4auto, we are engaging the center differential

When we switch to 4hi, we lock the center differential, making it no longer a "differential"

You are so far off base and incorrect in regards to GM 4x4 trucks/suv. You could easily educate yourself by crawling under your truck. GM trucks with 4wd only have 3 main parts to the driveline side of the 4wd system. They have a open front differential, a locker style rear differential, and a selective transfer case. The tail shaft from the transmission runs into the transfer case and then 2 drive shafts come out. one goes to the rear diff and one does to the front diff. From there since the front diff is independent suspension it is a CV axle system to go from the front diff to the steering knuckle/hubs

GM's system does not use any sort of vectoring at all in regards to power distribution like the Subaru/Audi and other AWD systems use. When in 4 Auto the system loads the transfer case clutch pack around 10%, as soon as the rear wheels detect slippage via the ABS sensor the transfer case locks in fully and splits the power 50/50 front to rear. From there the front diff provides a mechanical only power split equally to each tire left/right. On an open diff system the tire that loses traction (Example one on dry ground the other on ice) will end up with all of the power due to how open diffs work. If the rear diff has the GM G80 locker then once the locker locks in (it is a mechanical locker) both tires have equal power until the wheel speed reaches 20mph, then the fly weight governor in the G80 locker unlocks the diff and it operates like a open diff at that time.

When you are in 4Hi the transfer case is fully locked, power distribution is still the same though. When you go into 4Lo the transfer case engages a multiplier gear set to increase the torque output by gear multiplication. You are speed limited in this case if you use 4Lo on a GM system.

So please quit coming in here and trying to convince people that the GM 4wd system is the same as a GM AWD system or AWD in general as it is not.

truckguy82 · January 13, 2017

as soon as the rear wheels detect slippage via the ABS sensor the transfer case locks in fully and splits the power 50/50 front to rear.

this is where you are wrong! I know everybody thinks that because the damn thing actually called "automatic 4wd" one would think all it does is engage and disengage locking the driveshafts, since thats how 4wd works.

I'm well aware it doesn't have an actual center diff, but anything that can adjust a torque split and cause different speeds between the output shafts its connected do, is infact the basic definition of a differential. I only said differential to show that it is indeed similar to awd.

Also why keep using subaru, I already compared it do a different awd system that is more common than subaru's and audis. It's the good ol fwd bias awd with open diffs front and rear.

Silverado Steve · January 13, 2017

Please post info on this other than telling people they are wrong. Saying you heard it from another poster is not a good source. This is what is known as an academic argument or academic point of view; essentially supporting your position with a third party source. The whole intent is to help people out, preferably with factual information. Everyone on here has told you that you are wrong in your understanding that AWD does not = 4 Auto, including many prominent posters that know a lot about the interworking's of our vehicles, yet you continue to debate and tell people they are wrong. I respect you as a poster from your previous offerings, but I'm losing faith my friend. You are starting to become the next AlpineSled guy that got banned a few months back trying to pass BS as facts.

this is where you are wrong! I know everybody thinks that because the damn thing actually called "automatic 4wd" one would think all it does is engage and disengage locking the driveshafts, since thats how 4wd works.

I'm well aware it doesn't have an actual center diff, but anything that can adjust a torque split and cause different speeds between the output shafts its connected do, is infact the basic definition of a differential. I only said differential to show that it is indeed similar to awd.

Also why keep using subaru, I already compared it do a different awd system that is more common than subaru's and audis. It's the good ol fwd bias awd with open diffs front and rear.

truckguy82 · January 13, 2017

Please post info on this other than telling people they are wrong. Saying you heard it from another poster is not a good source. This is what is known as an academic argument or academic point of view; essentially supporting your position with a third party source. The whole intent is to help people out, preferably with factual information. Everyone on here has told you that you are wrong in your understanding that AWD does not = 4 Auto, including many prominent posters that know a lot about the interworking's of our vehicles, yet you continue to debate and tell people they are wrong. I respect you as a poster from your previous offerings, but I'm losing faith my friend. You are starting to become the next AlpineSled guy that got banned a few months back trying to pass BS as facts.

Im looking for gm documentation, found plenty of posts

Also right back at you

Why don't you post some evidence it locks the front and rear together for a 50/50 split. You haven't done exactly what your asking me to do!

redwngr · January 13, 2017

I understand this is not the same as AWD but Can I Drive in auto at 60mph ? ou I should avoid it ? and stay below 50 or so?

You can drive 60mph auto.

You can shift out for 4H at any speed.

You can shift into 4H at up to 75mph

You will need to be stopped (or less than 3mph) to shift into 4L and should not exceed 45 in 4L

4L disables traction control and stabilitrac

redwngr · January 13, 2017

Other brands have it, but it's optional, n ot on most models.

ALL GM have it.

When I looked at Ferd in 2010, only the HD model had it.

Only GM 1/2 ton have the Auto mode. HD's do not.

truckguy82 · January 13, 2017

Please post info on this other than telling people they are wrong. Saying you heard it from another poster is not a good source. This is what is known as an academic argument or academic point of view; essentially supporting your position with a third party source. The whole intent is to help people out, preferably with factual information. Everyone on here has told you that you are wrong in your understanding that AWD does not = 4 Auto, including many prominent posters that know a lot about the interworking's of our vehicles, yet you continue to debate and tell people they are wrong. I respect you as a poster from your previous offerings, but I'm losing faith my friend. You are starting to become the next AlpineSled guy that got banned a few months back trying to pass BS as facts.

Here you go, not perfect but pretty good

http://m.gmc.com/gmc-life/how-to/when-to-use-four-wheel-drive.html

AUTOMATIC 4 HI

If road conditions frequently alternate between high- and low-traction areas, consider using the AUTO setting found on select GMC electronic transfer cases. This setting allows your GMC to automatically distribute torque to the front axle by anticipating the need for additional traction. Shifting into auto engages the front axle, but the transfer case sends power primarily to the rear wheels in normal conditions and the clutches modulate torque forward to provide stability and enhance traction to the vehicle. Although not always optimal for efficiency and wear of your vehicle 4wd driveline, AUTOMATIC 4 HI can be used on any road condition without risk of damaging your vehicle.

"Clutches modulate torque"

Wait a second, that sounds just like what a clutch based differential does! I'm pretty sure they didn't say "clutches lock"