4 wheel drive vs. All whell drive?

[HOIST-N-HAWGS]

I'm nort sure if this is the right place to post but here goes.

I have a 2001 F-150 5.4L 4x4 and w/the price of gas I'm considering other options like Astro mini van AWD or a Safari AWD :-/. Heard good and bad about both. Always owned 4x4's and know very little about AWD.

What's the diference? Does anyone else tow there boat/trailer w/AWD?

There are some ramps here in New England that are pretty much beach sand and some fully covered w/slime, will AWD do the job? One more question, do they make any other AWD mini van type vehicles that can be used(efficiently) for towing?

Thanks in advance fo your advice and help!

[surfer]

I could be wrong, but this is my layman's take on it.

4WD is not safe to run on pavement.  There is no front to read differential.  So if the tires run slightly different distances something has to give.  That's the differentials job.  Without it the tires need to be able to slip (like on dirt) or the gears could break.

AWD has the front to back differential and is safe to run on pavement.  And it's always in 4wd mode.  

What I am not sure about is the positraction.  If one tire is stuck will it spin needlessly taking all the motion away from the other tires?  This would leave you stuck at the ramp if one tire is spinning in the sand.

[kreed]

I don't know about ALL AWD's but my wife's Element does not have low-range, and you can't switch it to 4wd manually. Once a tire slips the others start pulling. To my understanding it starts off in awd every time you start off and then the rear wheels stop pulling after it senses it is not slipping.

Don't know if that will help you any but that is all I know about it.  I wish my wife's at least had a low range to help keep from riding the brakes down long fairly steep slopes.

[ThomasL]

I better jump in here before wrong info is given.Now this is to only refer to the only vehicle that all wheel drive works properly according to test,subaru is THE only vehicle that has true all wheel drive.They offer two models symetrical in 5 spds that allows Each wheel to grip independently and uses only one transverse case,the other assymetrical in autos that allow the front to pull and when traction is lost power transfers to the rear.There is a test performed i think on utube and test all ALL wheel drive models(honda,toys,audi, vw,volvo.mercedes and of all the subie pulls with one wheel while the other three spin!

[Team_Dougherty]

Surfer has it right.

In a 4X4 if in 4WD and you turn tightly on a non slippery surface the inside back wheel will actually spin faster than  the car is going. You risk the chance of breaking the Xfer case.

My wife's jeep is is AWD and I notice that is is harder to turn on dry pavement than my blazer 4X4 in 2WD in a parking situation. The blazer is almost impossible to do the same maneuver in the blazer in 4WD.

In the jeep it is true AWD but it does have a low range. When in a slippery situation snow or wet ramp all 4 wheels will pull. In my blazer in 4WD only one wheel on each axle will spin on a wet ramp on in snow.  My guess there is not a posi or limited slip in the blazers axles.

[MyKeyBe]

http://www.powertrax.com/powertrax/tractioninfo.html

Probably a lot more info than you wanted but still a good read on traction. Watch the videos on the Powertrax web site. Pretty amazing.

By the way, my 93 Jeep Cherokee has the New Process 241 (Selec-Trac) transfer case that has a setting for Full Time 4x4 that can be used year round in any condition, dry pavement included.

Bassectomy,

I've been meaning to ask you, is that a wimeriener in your avitar?

[HOIST-N-HAWGS]

Thanks to all for the info! It looks like I staying w/the F-150 ;D

[HOIST-N-HAWGS]

http://www.powertrax.com/powertrax/tractioninfo.html

Probably a lot more info than you wanted but still a good read on traction. Watch the videos on the Powertrax web site. Pretty amazing.

By the way, my 93 Jeep Cherokee has the New Process 241 (Selec-Trac) transfer case that has a setting for Full Time 4x4 that can be used year round in any condition, dry pavement included.

Bassectomy,

I've been meaning to ask you, is that a wimeriener in your avitar?

Yes sir! that is the best Weimarner that ever walked the face of the earth!