Gear ratio, its the amount the driveshaft will turn before the rear wheels will turn. Think of it a lot like the gears on a 12 bike. If you have a big gear in the back, its a lot easier to pedal right... but you can't go as fast as you can only pedal so fast.
Gears like 4.11s and 4.86s are for drag racing. The allow the engine to rev quicker and hence the car will acclerate quicker, but at the expense of higher engine rpms. This is because the engine doesn't have to strain as much to turn the rear wheels. Just like trying to take off on your 12 speed bike, its a whole lot easier in low gear as opposed to high gear.
Gears like 2.80s, 3.20s are the opposite, they are better suited for the street. The engine won't rev as fast when trying to acclerate, but you also will have less rpms when crusing on the freeway. You'll notice better fuel milage because of this.
[color:red]1966</font color=red> [color:blue]V8</font color=blue> [color:red]Coupe</font color=red> http://www.geocities.com/2bav8
5 speed, 4.11s, 10.13 in the quarter mile.
Oh wait, that was a Sammy Haggar song...
THE GEAR RATIO ISN'T YOUR PROBLEM IF IT AT ONE TIME YOU WERE GETTING 25 MPG AND NOW YOUR NOT. YOU NEED TO LOOK CLOSE FOR A FUEL LINE LEAK. CHECK YOUR OIL AND MAKE SURE IT'S NOT OVER FULL. SOMETIMES THE FUEL PUMP DUMPS THE GAS INTO THE CRANK CASE. DENVER