Help

Had been confusing about this product which called voltage stabilizer.

Most of the seller claim that after installed with a voltage stabilizer will have following benefits :

Brighter headlamp
Better fuel consume
Smoother gear change (auto)
Torque and HP increase
Longer battery life
Cooler air con???

And so on, some say it needs to be works better with grounding cable. Some say only higher model will give benefits like Hot Izanma, Qmax. And another information from a shop which...