The 130/100 bulbs I had in my white car (with relays) lasted about 4-6 months, since I drive with low beams on all the time as DRL's. But WOW did they ever light up the road... 460w total on high beam
We run 100/80's (common motorcycle bulb) in our for-sale 450 SL, and the 400W of deer-finding (combust-a-cat?) high beams is truly wonderful. We're still on the first set of bulbs, but the car doesn't get a lot of dark miles put on it since they started salting the roads in winter here. -- Jim