now from what people have told me, cars usually have a "drive wheel" which puts power to the ground. 2wds have 1 "drive wheel" and 4wds have 2 "drive wheels". According to this article, the car has 2 drive wheels. Is this something common or new and what types of cars usually use this setup. also how does a limited slip differential differ or enhance this setup.

I am sorry if I come off as "uneducated" in this type of discussion but I really like to learn about this kind of stuff. Any other technical topics you would like to explain to me would be most appreciated.

 

from what i have learned:
well, in performance cars or trucks they usually have trouble getting traction, so they install limited slip differentials, so both wheels accelerate at the same rate. some even have locked rear differentials which is usually found stricly on offroad vehicles and drag vehicles. when the diff is locked you cannot turn the car without one drive wheel skiping. if you have a front wheels drive car, and you get stuck in mud or snow, you may notice only one wheel acctually rotates when you floor it. you can notice this when you drive one wheel onto someones front yard and leave the other wheel on the pavement and floor it. of chorse this only works with traction controle off. one wheel (the one on the yard) will violently spin and kick up grass and mud while the other just sits or rolles along on the pavement.
from what you heard is somewhat true. lets say a 4wd suv w/o traction controle is off roading. it gets stuck in a ditch on its side. most of the vehicles weight is on its right side, so the left wheels will spin and lose traction. it is stuck. if it had locked diffs all around it probably wouldnt be stuck.
traction controle and limited slip are similar, but one is usually for a manual tranny and the other is usually for an auto tranny. the limited slip-manual and trc controle-auto.
these are not too similar though. the limited slip is for performance because it automaticly keeps both driving wheels spining at the same rate, as if you were to roast them and get a good launch. with out limited slip you could have only one wheel roast andthe other just role along, but from what i'm hearing from these ss, it isnt a problem.
some cars like the subaru sti, has an adjustible 3rd diff. you can controle how much torq you want the front/rear wheels to have. like in rally racing, for driving on dry pavement you would want 50/50, where if your racing up a mountain, you may want 40/60 or even 30/70, as the car leans back on the rear wheels you can take advantage of its weight distribution. keep in mind though that this will change the behavior of the car's turning and power sliding.
basicly to prevent torq steer,you need both front driving wheels or both rear driving wheels to get the same amount of torq. one wheel usually gets a little more torq, so the car drifts a little to the opposite side. I think most cars usually torq to the left.
and in muscle cars with huge engines, it torqs to the direction the crankshaft is rotating. so if your sitting in the drivers seat and the crankshaft is rotating counter clockwise, then it will torq to the left, i believe. in the muscle car example i dont think there is much you can do to prevent the torq steer.
sorry for the long post. i hope i made some sense. remember this may not be 100% true.
anyone wanna critic?

 

sounds right, but i dunno if the cobalt has it or not

 

has what? the limited slip dif or the trc? only the g85 or whatever ss's have the limited slip. all auto cobalts have trc though.

 

It's not really about accelerating at the same rate.

Let's talk first about the "one wheel drive" thing. In a "normal" car, you'll have what's known as an OPEN DIFFERENTIAL. Under normal acceleration, both wheels do recieve power, so it's not really "one wheel drive". The problem with an open differential is that once one wheel starts to slip, ALL of the torque is diverted to that wheel, so the other wheel (the one that actually may still have traction) gets no power, and you sit there spinning.

Obviously that's not great. The alternative is what's called a LOCKING DIFFERENTIAL or LIMITED SLIP DIFFERENTIAL. Under normal operation (both wheels with traction), there's really no difference between an open and locking dif. The difference is when one wheel slips. While an open dif "lets go" and puts all the torque to the slipping wheel, an LSD still provides torque to the other wheel, allowing it to pull the car until the other regains traction.

There are a variety of cars with various combinations. Most cheap/small trucks have a non-locking rear dif. Expensive ones will have a locking dif (sometimes it also gets called traction lock/t-lok, etc.). Then there's AWD/4WD cars/trucks that can have either non locking or locking difs at the front or back. Again, really no difference until you start to slip.

The half-shaft issue is a different one completely. That half shafts comment refers to the length of the driveshafts between the trans and the front left wheel, and front right wheel. If the shafts are not of equal physical length, then when you accelerate, the car will have a tendency to pull to one side, called TORQUE STEER. It has nothing to do with whether or not the car has a locking differential, it's talking about a different issue. The torque steer issue is generally only discussed with FWD cars, because of the way the engine/trans is packaged, the shafts are usually not of equal length. On a RWD car, the driveshaft is right in the center of the car, so the rear axles are always of equal length (no torque steer).

So in answer to your question, ANY FWD car has two drive wheels. Until one starts to slip. Then, if you have an open dif, you just spin, but if you have a locking/LSD, you get some torque to the other wheel.