[CAPTAINJEH]

been having some discussion about when it's safe to use 4 wheel drive. picture a two lane road with 55mph limit that has snow in the center and inbetween the tires down the center of the truck. not much too often under the actual tires. hopefully that makes some sort of sense. would you keep it in 4 wheel while going 50-55 for about an hour? something tells me it's not the best for the truck but every so often we come across parts of the road that are all snow covered for stretches at a time. Thing is a buddy has a Z71 that has in 4 wheel all the freakin time when we're on roads like i described above with no problems and is trying to convince me to do the same it won't hurt anything. any opnions on this?

 

[IownandsellEB]

gas mileage will drop whenever you are in 4 wheel drive. I go by how the road feels not looks. But going off of what you described, I would keep it in 2wheel drive. You can shift into 4high at 60 mph so maybe just try to manage it as you go. But its about how you feel, be safe. You have a 4x4 for a reason and if gas is a second thought after safety, then keep it in 4wheel hi. but its up to you...

 

[AK-KingBoost]

Does your truck have the traditional/normal transfer case setup (2h, 4h, 4L) or the two speed transfer case (2h,4A, 4h, 4L). If its the latter you can run the 4wd at any speed even on dry pavement without harming the system.
If its the traditional or normal set up and your under 55mph like you said you will be fine to you it 4wd all day if you wanted based on the road conditions... Mpg might go down some but I would rather lose a gallon of gas here or there vs losing grip and losing a gallon of blood...
I recommend putting weight in the bed of your truck right between the wheel wells. I have 600lbs normally during winter time in the bed (200-400lbs is enough). I can run 2wd most of the time and if it gets to questionable click it into auto 4wd or 4wd...

 

[Mike Tritle]

4H and 4L locks the front and rear together with no differential. That's why its not good to use on dry pavement since no 4 tires are ever the same diameter. That generates driveline bind, especially when turning corners, that will shorten the life of everything from the transfer case to the CV shafts in the front. I usually switch in and out as needed by reading the road surface by color tint. If its wet, little to no problem but when slippery, yee hah, that's why I spent mula for the 4x4 option! The 4A option on the high end ones does introduce a differential and is more of an on demand system. You can run that all day every day year round. Thats the difference between All Wheel Drive and Four Wheel Drive. But, AK and Iown are corrrect, it introduces more driveline parasitic losses and will affect fuel mileage. In most cases I use mine, that's a moot point!

 

[CAPTAINJEH]

Great info guys thanks! No 4 auto so I'll be doing the selecting myself as i see fit. And it sounds like since we're pretty much going straight the whole time since it's kind of a highway i won't have to worry about binding up in the turns because the roads not quite slippery enough I should be fine.
One last question I just thought of. How about the summer months how often do you put it in 4H to give it a little workout? And what if you don't have anywhere to do that other than dry pavement or rain?

 

[AK-KingBoost]

Great info guys thanks! No 4 auto so I'll be doing the selecting myself as i see fit. And it sounds like since we're pretty much going straight the whole time since it's kind of a highway i won't have to worry about binding up in the turns because the roads not quite slippery enough I should be fine.
One last question I just thought of. How about the summer months how often do you put it in 4H to give it a little workout? And what if you don't have anywhere to do that other than dry pavement or rain?

Summer time is fun time Bro. Don't worry about engaging the 4h to keep things frosty and free moving. Just roll in 2wd and within reason of the road conditions. If you venture off road go until you need 4wd (Be amazed how far you can make it) or when you need the extra traction like a wet boat ramp. If you have the elect locking rear you could always use that first before going to 4wd (This is for slow and slippery conditions not drive pavement where traction is not a issue).

 

[CAPTAINJEH]

Thanks again I think I'm good to go on understaning all this. For now anyway.......

Jason