The standard H4 60/55 watt and it's recommended that you stay with that bulb.

Although 100/90 watt bulbs are available, the wiring in the vehicle is not up for that task without a proper set of relays. In addition to obtaining far less than 100/90 watts from the bulbs, you'll develop quite a bit of heat in the wiring, potentially damaging the insulation if it continues for sufficient time.