Headlight wattage question

After seeing all the posts indicating favorable results with Silverstar bulbs, I bought a pair to put in the Depo euros I am installing. I did not notice until I got home that these are rated 65/45 watts. (H4 ST, 300E)

The question I have is when on high beam, are the wattages are additive?

Since I no longer have to drive 80 miles through the country to get home every night, I now seldom use high beams and welcome the higher wattage on low beam, but if the wattages are additive, the Silverstars put out 110w on high beam where the stock bulbs (55/60) put out 115w.

Am I missing something here? Could high beam/low beam usage account for the differences in opinions on these bulbs?

This all started from wondering if the stock harness/relays would handle the higher wattage bulbs as some have suggested. If based on total watts, it looks like there is no problem.