So the SilverStar Ultra's would likely get me the closest to the OEM HID's while staying Halogen and not risking electrical problems.
Color temperature wise - yes it will look more like HID than other incandescents. I have silverstars in my other car and I also have HID foglights - they are quite similar in color temp visually (but not exact match), much bettert than stock halogens. They are still not as bright as equivalent HIDs, but better than stock halogens.
Now the rated power on these aftermarket bulbs is actually hard to utilize by just swapping bulbs. Stock vehicle wiring is usually not sized generously and drops voltage even at the stock power levels - at higher power (bulb specs) it drops more voltage which means you don't actually achieve the rated power levels.
There are four primary effects from this:
1. It tends to protect the stock wiring from too much current which can overload the wires (especially where routed bundled in looms) as well as connection points and switch terminal degradation issues. Now you still do have higher circuit power & current so all these are still possible... but not as bad as they might have been without the voltage drops across the wiring.
Power in an incandescent bulb is ~proportional to V^1.6 due to the filament resistance variation with temperature.
So A drop in voltage causes a larger drop in power (but not as a square law for a bulb).
2. You don't achieve the maximum brightness in lumens the bulb could produce at its rated voltage. Brightness is ~proportional to V^3.4 so voltage plays a major effect here and you loose brightness rapidly with reduced voltage.
3. Bulb life is reduced for high output bulbs since they are both manufactured and sub-selected to have tighter tolerances but then are run much closer to their limits than general market bulbs. Small deteriorations in the filament over time will cause them to burn out rapidly.
Bulb life is however ~inversely proportional to V^12-16. So small reductions in voltage due to wiring losses increase bulb life dramatically - as in this case.
4. Color temperature is measured at the rated point but it varies with filament temperture and that varies with power which varies with voltage.
Color temperature is proportional to V^0.42 so color temperature will reduce slightly with voltage reduction.
So there are risks to the vehicle wiring from bulb upgrades, but they are different risks. If you just plug a higher rated or a specially selected (e.g. silverstar) bulb in you will also have these effects limiting you from achieving the specified ratings. Vehicle damage is also possible depending on the power levels you select.
Alternative:
Local HL relays fed with big wires from the alternator and to the lamps, controlled by the stock lighting wiring can protect all the stock configuration car circuits, reduce all these voltage reduction effects significantly and get you better brightness, higher color temperature (and consequently much lower bulb life!).
Other considerations: I'd be surprised if the lens/reflector optics are the same between halogen and HID. The focal points and shape are very different between dual filament halogen and single arc HID. Swapping a HID light source into an optical solution for Halogen usually results in non-optimal performance - most often compromising high beam performance. Now if the Explorer halogens really are single filament with a high beam movable shutter this may be less apparent (possibly even mostly designed out). But then there is some risk that higher power dissipation levels will damage the shield movement mechanisms.
I think upgrading to better halogens is actually a fine start - but local relays would make this a much more effective solution, and reduce risks of damaging the car wiring. Local relays will likely make even stock halogen lights brighter.
In my other car with local HL relays, uprated Silverstar halogen headlights in eCode pattern - HIDs do not compare well - the brightness is higher - but the focus & cutoff is terrible on high beam and poor even on lowbeam.
Uprated higher color temp halogens (like silverstars) are just perfect on both... now this is in old style reflector/lenses that are designed optimally for Halogen only.
So it all depends. Uprated halogens are far cheaper than HID, local relays can be inexpensive if you implement yourself, or more similar to HID pricing if you buy the available kits.
Alan
, is that 4300k is as close to natural daylight as you can get. As the Kelvin (k) numbers go up from there, the light output (lumens) decreases.
