Why does one wheel spin in the opposite direction on a car?

Question

Why when you raise a car off the ground and spin one wheel with the car in neutral the opposite wheel on the other side of the car spins in the opposite directions. But when the car is in drive they both spin in the same direction.

Answer 1

That's because the engine is off and LOCKING the center.  

The differentials allow the wheels to spin at different speed.  If the engine / tranny was spinning forward, then one wheel would spin SLOWER not backward.  Remember that the wheels speed it RELATIVE to each other.  If one wheel turn 10 RPM and another at 5 RPM, essentially one is like turning backward to the other.

Without the differentials, your tires would screech every time you make a turn - because the outside tire would want to make a bigger CIRCLE than the inner tire.

Good Luck...

Answer 2

Differentials as lover not a fighter already said.

Answer 3

Wow...never knew that, but as long as my car doesn't do that while I'm DRIVING, I guess it doesn't really matter!

Answer 4

Because of the differential.