Below is the comparison of the standard and Sylvania SilverStar(America) H4 bulb. SilverStar consumes more power but does not give more light.
Standard H4, Watts: 55/60, Lumens: 1000/1650
Sylvania SilverStar H4, Watts:60/70, Lumens: 1000/1400
If you like to get more light on the road, try Philips Vision Plus H4 for about $28 includes shipping from:
http://www.autolamps-online.com/home.htm
You can get a free pair of all season H3 with purchase of a pair of H4 Vision Plus of Osram SilverStar for about the same price from:
http://www.powerbulbs.com