The gears would allow the engine to have better "leverage" if you will on the motor. It makes the tires spin roughly 4 times for every 1 turn of the motor. You would in fact feel less lag because of the gearing. It will lower your top speed, for increased acceleration. That is why you would be able to use 5th gear to "play" on the freway. ;) [I'll revise and elaborate if you need me to, or I didnt explain it correctly]