I have a mk5 2016 mondeo the head lights aren't much brightness the car came from the factory like this if I up grade to a brighter bulb will the wiring be OK as the bulb will be much hotter 

Is yours the model with the DRL's in the headlight, if so brighter bulbs won't make a huge difference as the reflector design is not great.

You can change to something like Osram nightbreakers, don't change to bulbs that are higher wattage that will burn out the holders and damage the lenses high output 55watt is what you want, but as I said there will be an improvement but not that great, in fact new bulbs allways make a difference, yours will certainly be a little tired by now

I put Phillips Xtreme Vision in mine as the stock bulbs where rubbish! A candle would have been better but the Xtreme bulbs where better and lasted me 2 years, so imo are better than Osram bulbs which I’ve only ever got 6months out of them. 

Agree with @pragmatix about bulbs over 55w, the harnesses will take the extra load but the holders will surely melt. AFAIK there are no ‘reflector’ lenses even on the ones using H15 bulbs for integrated DRL, they are all projector lenses.

@Jonro2009 yes they are projector headlights Maybe I should just have said the headlight design is not great

I don't know if this is of any use to you (I don't know what bulbs you'd have in a Mk5), but I recently bought a HID kit for my Mk3 - 4xH7 for main beam and fogs, and 2xH1 for the full beam. The brand was N7 or something, about £35 on Amazon for a set. They're equipped with a cooling fan and a heatsink to prevent overheating, and the ballast regulates the wattage or something? You might be able to find something similar, but as I say I have no idea what bulbs you've got. My '05 Mondeo is the newest car I've ever had, unless you count the 2011 BMW 330d I had for a week before deciding I hated it and asking for my '99 Accord back xD

And the new MOT reg's coming in in May state an aftermarket HID conversion will now be an MOT failure.

which means precisely diddly squat. if it looks right, it will pass. if its sporting blue lights and crap patterns then you can expect it to be spotted but then anyone with any sense uses 4300k HID bulbs which is what most normal OEM bulbs are. So it becomes one of those grey areas.

 

I have upgraded my headlight bulbs on my 2017 Focus  with RING Xenon 150 H7 bulbs which are road legal no wiring change headlights are a bright white light instead of the yellow glow of the factory standard fit 

4 hours ago, JAKE191 said:

I have upgraded my headlight bulbs on my 2017 Focus  with RING Xenon 150 H7 bulbs which are road legal no wiring change headlights are a bright white light instead of the yellow glow of the factory standard fit 

Those are just a tungsten lamp filled with xenon gas not a xenon discharge lamp.

On 3/31/2018 at 4:42 PM, Dee_82 said:

which means precisely diddly squat. if it looks right, it will pass. if its sporting blue lights and crap patterns then you can expect it to be spotted but then anyone with any sense uses 4300k HID bulbs which is what most normal OEM bulbs are. So it becomes one of those grey areas.

 

And, as you point out. it won't look right as soon as they check the beam as without the right lens it will scatter, plus any MOT tester with a brain cell will see a non-OEM ballast pack, lack of factory fitted washers and fail it.

 

And yes, I'm aware that headlight washers are not a requirement but how many OEM fitted HID lights come without them and an auto leveling system.

That points more to the failings of the MOT rather than the tester. I mean I have HIDs in projectors in my Mk2.5 focus, retrofitted, I retrofitted washers as well but no levellers. never had a problem at the MOT. the pattern is fine (in fact the new MOT actually makes it easier to pass the pattern test) BUT

if you stick HIDs in a reflector you need to castrated, if you stick HIDs in a halogen projector as you say the pattern will be off. but if you put HIDs in a HID projector as I have done, there very little they can do to fail it. the ballast is under the lamps. you cant see anything. 

I totally agree that anyone contemplating HIDs today needs to think long and hard about doing it. unless you do it right (and you dont need the levels and washers but it helps) then you will probably get caught out. after I did all the conversion work it was actually only slightly less then buying OEM Xenon lamps. with hind sight, im never going to open up a set of permaseal lamps to convert them ever again :D