I just changed my head lamp from stock Philips H4 60/55W to Silverstart (Sylvania) H4 ST. This is way brighter. Changing it was a little painful, getting the screws back in to hold the assembly together. I recommend pointing the light @ a marked spot on the wall, prior to removal, so when you put it all back together, you can re-site it. Also, make sure you do not touch the glass of the bulb - it will cause it to burn up quicker.

This is all about making you safer by making you more visible to cars during daytime riding.

 

ur using the same type of bulb though and i was pretty sure an H4 has the same wattage across the board-but if it is different and as long as it is legal then i guess it would be ok.