so my mom bought a used kia sportage... and it turned out to be a lemon of sorts...

it's only been a couple months and she's had to fix the PS pump belt, and there's a leak in the top of the gas tank, the ball joints need replacing, and her front u-joint is going...

anywho, back to the question at hand... the thing has 4wd in a hi/lo setup... she drives it in 2wd normally, but i'm wondering which wheels are the power wheels, and whether it would be easier on the u-joint if she ran it in 4wd lo (providing the torque split is more towards the rear than the front)... maybe i'm misunderstanding how configurable 4wd works.

i know powering all four wheels can use more gas, but i've also heard driving it in 4wd mode is bad on the powertrain if it's being driven on pavement...

ideas? she plans on fighting the dealer at some point because of it being this way when she bought it, but i figured the less wear on the fronts, the better (at least in the meantime)...

The u-joint is still spinning no matter whether the transfer case is in neutral, 2wd, or 4wd.

When a 4x4 is in 2wd mode, the power is sent to the rear wheels.

as sam said its the rear wheels, i dont know of and 4x4s that put power to the front wheels in 2wd mode.

as for 4wd being bad if on the road that only apies if there is no centre differential, land rovers for example have a centre diff and permanant 4wd. as for running in 4wd low, low ration settings on transfer boxes are usualy very low, i know they are on the land rovers and are not usable for everday driving

Quote from wheel4hummer :

The u-joint is still spinning no matter whether the transfer case is in neutral, 2wd, or 4wd.

Wrong.

Quote from sam93 :

When a 4x4 is in 2wd mode, the power is sent to the rear wheels.

Kia Sportage isn't necessarily a 4x4. Not all 4WD run in RWD when in 2WD mode. My Mazda Tribute is FWD/4WD.

But, I don't know how the Kia 4WD system is. It sounds a little older of a vehicle because the majority now transfers power to 4 wheels when it senses (they are automatic.) I would guess not since you have a switch. The older Ford Escapes/Mazda Tributes use to have a transfer case and 4WD, but now they are automatic and it is a type of AWD for example.

With a true 4WD system, the front and rear drivetrain is locked together via the transfer case. When you are turning in 4WD, your front wheels will be rotating at a faster speed than the rear because they are traveling a longer distance. Think of how the differences are in LFS between the left and right wheels with the locked differential. Same principle. Thus, on dry pavement, when trying to turn, the front wheels will "chirp" signifying that they are trying to spin (well, not trying, they are.) The transfer case in this instance is binding up and forcing the front to spin and unbind the t-case. This is not good when driving at normal conditions and the t-case will eventually break.

Low range is merely a much lower gear ratio. You probably couldn't get the vehicle up to 45 mph at redline in top gear. It is for off-road only.

You can drive in snow/ice conditions just fine in a locked 4WD system because easy slippage in the snow keeps the front drivetrain from binding up.

As james12 said, AWD has a center differential and allows the front and rear to spin at different speeds.

What year of Kia Sportage? I test drove one in 2007 and I believe it was automatic 4WD (like my Tribute) with a center differential lock switch and no low range.

i stand corrected on the fwd/4wd front then , never heard of one like that tbh, to me it makes more sence to have it as a rwd/4wd

FWD is better than RWD in snow. It is easier to pull a vehicle than it is to push. The FWD craze started in the early 80s.

RWD needs a tire replacement for driving in the snow. Keep the same tire on it in summer and winter and you will just sit at any intersection, stopsign, or traffic light and spin. FWD can pull a car with relative ease from a standstill in snow with the same tires. (We generally use all-season tires here, not switching to a "summer" tire as I've seen talked about here on the forum.)

More of these car based "Crossover" SUVs are going towards AWD or this newfangled "automatic" 4WD systems. Quite frankly, just like an automatic transmission, I think these auto 4WD systems suck as well. When I am in 2 feet of snow, I want to know that I am in 4WD. In my opinion, when it says it "senses slip", isn't it too late? Hasn't the tires already slipped if it is sensing slip? Give me back my damn lever moving a mechanical connection, Grrrrrr....

i see what your saying about snow but if you have a 4wd/rwd in snowy conditions uyou would use 4wd anyway .

and lol atn the bit about sensing slip, yh shouldnt be slipping in the first place, you need the traction control but in conjuction with a normal 4wd system. the landrover discovery 2 can be a very formidable offroad tool because on some of them they have traction control and centre difflock on a normal 4wd system

Quote from mrodgers :

FWD is better than RWD in snow.

I can't see why FWD has any inherent advantage. I'd imagine it's just due to most cars being predominantly front heavy, so you get more traction with FWD in low grip conditions (where the lack of grip prevents acceleration, thus little rearward weight transfer).

Quote from Bob Smith :

I can't see why FWD has any inherent advantage. I'd imagine it's just due to most cars being predominantly front heavy, so you get more traction with FWD in low grip conditions (where the lack of grip prevents acceleration, thus little rearward weight transfer).

I think you've just answered your own question?

Quote from Bob Smith :

I can't see why FWD has any inherent advantage. I'd imagine it's just due to most cars being predominantly front heavy, so you get more traction with FWD in low grip conditions (where the lack of grip prevents acceleration, thus little rearward weight transfer).

its also safer for the great unwashed to drive a car where the rear will so whatever while the front stays nicely in line as opposed to one that has a tendency to swap ends

Quote from Nathan_French_14 :

I think you've just answered your own question?

he didnt ask a question