A Guide to Upgrading Your 4th Gen 4runner Headlight Bulbs

If you’re thinking of upgrading your 4th Gen 4runner’s headlight bulbs, you’ve probably already noticed that there are a ton of options to choose from out there. In this guide, I’ll break down the various ways you can upgrade yours and compare some of the pros and cons.

There is always a chance that you’ll bother oncoming drivers when you swap your headlights out with brighter ones. Yes, the type of bulb and housing plays a huge role, but even if everything is technically “perfect”, the brightness can still annoy people. Changes in elevation, corners, and weather conditions can cause your headlights to hurt other peoples’ eyes. 

There are plenty of stories of people getting flashed by other motorists for their OEM headlights, and I’m sure a lot of awful aftermarket headlight setups go for years without any complaints. Whether or not people flash you is subjective and not a proper test in terms of glare or beam pattern.

4th gen 4runner headlight bulb sizes

First, here’s a quick list of the proper headlight sizes for the 4th Gen Toyota 4runner. Keep in mind that there was a facelift in 2006 so those models and newer have updated projector headlights. Both the earlier models and facelifted ones used halogen bulbs though.

	2003-2005 4runner	2006-2009 4runner
Low beam	9006	H11
High beam	9005	9005
Fog	9006	9006

H9 Halogen conversion – the most respected choice

Aside from retrofitting new projectors and upgrading to HIDs, H9 halogen bulbs are the most respected way to increase light output without blinding oncoming drivers. This involves very minor trimming to make them fit in place of an H11 bulb but it can be done quite easily. 

The biggest selling point of the H9 conversion is that you’re putting halogen bulbs in a headlight that’s designed for halogen bulbs. This is your best chance at maintaining a proper beam pattern with very little additional glare or scattered light. 

These halogen bulbs are more of a function over form solution. They’re certainly effective, but they don’t necessarily look like an upgrade. The color temp is the same, they’re just… brighter. Not super exciting, but clearly the safe choice.

Some people have reported a noticeable increase in heat with these bulbs, since they’re rated for 65w vs 55w of the H11. Some even complained of a minor burning smell coming from their engine bay. In reality, the 10w difference shouldn’t be enough to cause any problems. 

It’s also worth noting that a brighter halogen bulb simply will not last as long as a lower powered one. That’s a trade-off that you make when choosing this upgrade. The good news is that headlight bulbs on the 4th gen 4runner are really quick and easy to change – just know that you might be changing them more often with these H9 bulbs.

There is an extremely in-depth thread on the Tacomaworld forums that talks all about upgrading from factory H11 bulbs to H9 halogen bulbs. If you want to learn more about the science behind some of this stuff, make sure to head over there to check it out. 

Pro	Con
Proper beam pattern	No cool white appearance
Inexpensive	Run higher temperatures
Much brighter over stock	Requires trimming to fit
Warm enough to melt snow off headlight lens

These Philips H9 bulbs come highly recommended by people who want to increase their vision at night without affecting other drivers.

LED bulbs – the easiest upgrade

Aftermarket LED headlight bulbs are a very popular upgrade for 4runner headlights. They provide a (seemingly) brighter light, a cool, modern appearance, and a long lifespan. 

They also use a lot less power, in turn running at cooler temperatures. There’s no modification required – these will swap right in place of your original halogen bulbs in minutes.

Things are not always as they seem though. Putting an LED light bulb in a projector that’s meant for a halogen bulb provides less “focused” light. Essentially, the light output directly in front of your vehicle is great, making you think your headlights are brighter. But because they’re less focused, the light they throw further down the road can be either the same or worse than your OEM halogens. 

Some high quality LED bulb manufacturers are trying their best combat this by finding ways to make their chips increasingly slimmer to mimic a halogen bulb. They might not be all the way there yet but they’re certainly a big improvement over the older/cheaper designs.

For my personal 4runner, that’s totally acceptable to me. I don’t rely on my low beams if I’m out in the middle of nowhere in the pitch black. I have high beams and LED lightbars if I need to turn day into night. 

I run Auxito LED bulbs in both my Tacoma and 4runner and have had great results with them. There are plenty of really cheap options out there for LED bulbs but it definitely pays to get some from a more reputable company like Auxito.

I’ve compared these to the OEM halogens on my Tacoma and the no-name LEDs on my 4runner and they were a big improvement over both. I’ve personally driven other vehicles while being followed by my own trucks and neither blinded me through my mirrors – even while driving my lowered MR2.

If you’d like to give these Auxito headlights a try, make sure to use code GEARHEAD for 15% off your order!

Pro	Con
Easy, direct installation	Less focus means less light down the road
More modern appearance	Cheaper options can be very low quality
Bright light that uses less power	Temp too cool to melt snow/ice from lens

HID bulbs – the “flashiest” setup (pun intended!)

I have a confession to make. I used to have plug-n-play HID bulbs in my previous Jeep Grand Cherokee. I’m sorry.

Putting HID bulbs in a housing intended for halogens is not a good idea. Yes, HIDs are bright – very bright. In a way, they’re too bright. The factory headlights are actually meant to take some of the available light and shoot it upwards so that we’re able to read street signs at night (sometimes referred to as “Squirrel Finders”). 

Replacing the light source with a super powerful HID sprays way too much light in this direction, blinding oncoming drivers. Some people will claim that it’s just a matter of aiming them downwards but unfortunately, you’d have to point them so far down that you’ll lose the benefits of the brighter light.

Putting overly bright headlights in your 4runner and pointing them straight at the ground so they don’t blind people just doesn’t make much sense.

Pro	Con
Very bright light	Excessive glare from light escaping
Modern appearance	Not “instant-on” – takes time to fire up

HID retrofit conversion – The ultimate upgrade

Think of a proper HID setup as the ultimate upgrade. This can be achieved either by retrofitting a set of HID projectors into your headlights or buying aftermarket light assemblies that are designed to use HID bulbs. 

If you want a lot of bright light with minimal glare, this is the solution for you. Unfortunately, you’re going to have to pay for it. The reason you see so many people making sub-par upgrades to their headlights is quite honestly because it costs a lot of money to do it right. 

You’ve got to have deep pockets if you’re going to upgrade to a proper HID setup but if you do, it’ll certainly perform well. Admittedly, it can be a little hard to justify spending the money on headlights when that same amount could buy you a high-quality set of coilovers or a set of tires.

Pro	Con
Brightest option	Very expensive
Minimal glare for oncoming drivers	Difficult installation (retrofit)

These aftermarket headlights from TEQ Customs are becoming pretty popular among 4runner owners and seem to be pretty cost-effective as well!

Final word

Regardless of what upgrade you choose to go with for your 4th gen 4runner headlights, I think it’s important to at least test them from the perspective of other drivers. You might not have a lux meter available and you might not fully understand what’s right and wrong about a beam pattern.

But the least you can do is switch cars with a friend and see how your new headlights affect other drivers for yourself. If they seem too bright for you, they probably are.