From Sylvania:
Q) How long do the headlights last?
A) The life of any halogen bulb varies based on vehicle type, vehicle voltage, amount of time the bulb is on, road conditions, proper installation, and correct application. The average life of SilverStar® headlights is approximately one year. With our SYLVANIA SilverStar® products, the primary goal is to offer the brightest, whitest light. Research has shown SilverStar® headlights improve driver visibility and reaction time. However, since our SilverStar® headlights are up to 35% brighter and our SilverStar® ULTRA headlights are up to 50% brighter than standard halogen, they may have a shorter life span compared to our other products.
SilverStar® ULTRA bulbs provide up to 40% increased down road visibility, up to 50% increased side road visibility and up to 50% brighter light, compared to worn standard bulbs. SYLVANIA SilverStar ULTRA bulbs deliver the whitest and brightest light of all the SYLVANIA halogen headlamp families.
I wouldn't say the ULTRA bulbs have 50% of the lifespan of regular bulbs, but they are definitely shorter. They burn brighter and hotter, essentially over-stressing the filament, thus they burn out quicker. But again, I'm fine with that. I've had them replaced by Sylvania and Walmart with no problems.
I want
bright.
It's all about Watts and lumens, and the corresponding hours of run time. Standard OEM H7 bulbs, for example, have 1400 lumens and are 55 Watts with a run time of 300-450 hours. The same H7 Silverstar ULTRA bulb gets you 1620 lumens at the same 55 Watts, but with a run time between 200-400 hours (depending on the electrical system in your vehicle).
There is another option, albeit legally questionable (actually, since the laws of North America state that low beams are to be 55 Watts, it's not all that questionable). You can get Osram's (which is also Sylvania)
Osram Rallye 65w Ultra High Output H7 "Special-Service" Bulb, which gives you 2100 lumens and a 300-400 hour run time. A lot of people here in the US are using these bulbs.
As much as I want
bright, as squirrelly as the Sprinter's electrical wiring is, I'm too chicken to find out what a 65W bulb will do to a 55W circuit. The chances are that it'll be just fine, since few if any problems with these bulbs can be found online, or the most that could happen is a blown fuse or a quickly blown bulb. Buuuut I've seen the wiring on a Sprinter, and I've already had a couple of oddball electrical problems as it is, so I'll play it safe.