Hi all.
A common moan of mine (and I'm sure many, hence this post) is that the H1 and H7 Halogen Headlight Bulbs in my X-Types and XF are prone to blowing frequently and, in the X-type especially, the headlights are bad enough without a blown bulb.
So.....
After deciding not to mess about with after-market HID upgrades for the XF (due to both the hassle involved and potential MOT issues in the UK) and basically getting p'd off at changing bulbs every few weeks in the Scottish winter, some trial and error with upgraded, super-bright, ultra-brilliant, and reinforced, long-life bulb options, I finally settled on Rally Bulbs.
Yep. Rally bulbs.
Available from Halfords (and I'm sure other retailers), they are actually cheaper than the other upgrade options.
In the X-Type the non-road legal (in UK) Rally Bulbs increase the wattage from 55W per side to 100W per side. "Hold on there! That's a massive extra load on your wiring loom, fuses, relays, lenses and switch gear", I hear many mechanics cry. Yep, it sure is.
In my case, they all seem to have coped with absolutely no issues and boy do these reinforced Rally suckers last much, much longer. And, yes, they are clearly much brighter too (which means a lot safer for all road users). So much so that they bring the X-Type headlights up to merely adequate. A marked difference, but in no way enough to negatively impact other road users or draw unwarranted attention with Her Majesty's Constabulary, or at the MOT station.
The XF Rally Bulbs increase wattage from 55W per side to 80W per side. A less noticeable brightness and load difference, but with the same impact on longevity.
In both cases (XF and X-Type) mine have been in for months (the XF two winters) and thousands of miles in all road conditions, with the possible exception of sweltering heat (this IS Scotland).
So, if you are having a 'mare with blown halogens in either the X-Type or XF, consider the Rally Bulb option.
The only caveats I would put in place are: while I've had no issues with fuses, looms, relays, lenses, or switches; it doesn't mean you won't! So do consider the potential down side (electrical fire, anyone?) and run tests before loading the kiddies in please! Oh, plus the fact that they are, strictly-speaking, very slightly illegal in the UK at least. Not wide-boy, stupid illegal, just a tiny wee bit.

 

wat007, I wish you luck in getting the plugs off of those headlights here in a little bit. The problem that some X-TYpe owners have had with the 55W bulbs is that the connector on the bulb melts and leads to high resistance connections and therefore the bulbs not working. That is what it sounds like you were suffering from. Installing new connectors (especially those rated for high temperature conditions) seem to help out a lot of members here. Because you are running 100W bulbs, your bulbs are going to be running that much hotter and leading to a higher rate of corrosion on the connectors.

Another thing to thing about is the wiring inside the headlight housing is not that heavy duty. I call it barely adequate for the stock power. When you start pulling more current through the wiring, it can become essentially what I term "toaster element". Yes, the wiring can get hot enough that the insulation will melt off of the wiring and may even start to glow red. As you can imagine, not a good situation. So I would do a good look at the wiring and see if the insulation is starting to show signs of heat damage. Much easier to do this check than to be driving down the road and then suffer a BBQ'ed leaper.

 

Hi Thermo.
All valid points and ones which I considered and actively worried about initially.
I checked frequently in the first few weeks and have had the bulbs out a couple of times in the XF since last winter (just to check).
My daily commute is 100 miles, roughly third rural, third high speed motorway, and third city (a lot on cobbles!) and we had thirteen speed bumps on the last half mile to our old house. Gotta love sh!tty councils. So I was blowing bulbs all the time.
The XF has done about 20,000 miles over 16 months or so on the Rally bulbs. Might have changed each one once.
The X-Type is more recent (one winter) and does very little mileage by comparison. That said, I had to replace one this week due to a spectacular pot hole incident (thankyou Glasgow City Council) and all appeared fine at that point. Might make more of a point of checking the X-Type again in few weeks, just because the draw is that bit higher again.
Cheers.

 

I found the super extra bright bulbs blacken and dim very quickly. The best ones I have used are GE standard 55w H1. The tips of these are ground back and shaped, rather than leaving a sharp point. I think this works better with the projector lenses in the x type.