Review of AuxBeam 9004 LED bulbs in a Volvo 240 aeronose:
I usually order BeamTech LED bulbs but there was no 9004 on Amazon, so I tried these. The AuxBeam's odd triangular LED post means that the focal point is about 1/8" off from center in every direction. So the light doesn't come from the middle like a filament does.

They are bright but the pattern on the road is odd, nothing like the sharp cutoff claimed on the box. The low is a blob but with too much spot in the middle. Then you hit the highs and there is a bunch more wide light down low ... what the heck? High beams are too wide up high too, so you can't see far down the road.

Those pattern anomalies are surely caused by the LEDs being in a triangle. None of the 3 LEDs is in the correct spot to mimic a halogen 2004. The secret of a good LED bulb is super thin LEDs as close as possible to where the filaments are in the halogen bulb for which the headlight was designed.

Installation is not easy because the fan on the back is much bigger than the 9004 connection. Volvo or Ford retaining rings won't fit over the fan. So you have to remove a tiny screw, pull off the O-ring base taking care to note its orientation, put on the vehicle's maintaining ring, then put the O-ring base back on in exactly the same spot, one of four holes.

After all that installation, the AuxBeam bulbs are loose in the headlight assembly, wobbling around. If not, I'd run them for a while and give them a try. But it's not worth trying when they are loose. Vibration on our rough country roads will kill something. So back to Amazon they go and I'll see if I can find BeamTech 9004 bulbs on fleabay etc.

On the plus side, the cutouts on the O-ring base do prevent indexing the bulb incorrectly. It will only go in one way. I can't say the same for Lasfit LED bulbs. The set I have in an F350 are easily and accidentally installed incorrectly clocked, due to shallow, weak alignment grooves.

Update: BeamTech apparently does not offer a 9004 anymore. Sure, I could rewire the socket slightly and run 9007s, but that's an axial filament, vs transverse in a 9004, so I'd expect poor light patterns on the road. Again...

I found that Auxito makes 9004 LED bulbs, and having had good results with that brand's backup and turn signal bulbs, I decided to order them up. Auxito makes the cool "switchback" park/turn bulbs I run in an F350, mentioned in another thread.

The Auxito 9004s are fan-less so the Volvo retaining ring should slip on easily just like a halogen. The heat sinking for the LED bulb is inside the lamp assembly, but given the large volume of late-model 240 headlamps, that should be fine.

I'll post an update after trying them out on a Dark and Stormy Night. After all this, I have no expectation that lighting will be as good as genuine E-codes. But even when living in France I suffered stone damage to my 240 E-codes. Here in Texas, gravel flies like crazy 24x7

The Auxito LED bulbs are satisfactory. I recommend them for anyone who it sticking with stock lenses. That said, they are not E-codes. I lived in Europe and had E-codes there. But they cost a lot here, and they are subject to stone breakage.

The Auxito pattern is fuzzy, and has spikes here and there. But in the aggregate, the light is roughly where you need it.

Keep in mind that we live rural Texas, and our night time driving is on relatively narrow, dark roads infested with suicidal deer. So my requirements are no doubt higher than those of you who live in urban or suburban settings.