Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Higher wattage headlamp bulbs safe?

Featured Replies

hey guys

my niece bought some halogen bulbs on ebay for for $10 for her 03 impreza. I went to put them in for her and they do not fit...but they DO fit my 96 OB.

 

I installed them today-they are the blue colored bulbs

I looked at the wattage of the stock ones and they are 60/55W H4

The new ones are 100/90W H4

 

Are they safe to use?? That's a big difference

 

There was a tiny packet of grease and some cheesy translated instructions (Japanese/Korean?) saying it was imperative to apply the grease to the prong/female connectors

 

Is this silicone grease? Just wondering if I should put more on

 

thanks

(have not had a chance to go out at night with them but I am sure they wil be an improvement)

hey guys

my niece bought some halogen bulbs on ebay for for $10 for her 03 impreza. I went to put them in for her and they do not fit...but they DO fit my 96 OB.

 

I installed them today-they are the blue colored bulbs

I looked at the wattage of the stock ones and they are 60/55W H4

The new ones are 100/90W H4

 

Are they safe to use?? That's a big difference

 

There was a tiny packet of grease and some cheesy translated instructions (Japanese/Korean?) saying it was imperative to apply the grease to the prong/female connectors

 

Is this silicone grease? Just wondering if I should put more on

 

thanks

(have not had a chance to go out at night with them but I am sure they wil be an improvement)

 

Its nice to have higher wattage globes I know but are you prepared to take the risk to melt your headlights?

Cheers

AP

Its nice to have higher wattage globes I know but are you prepared to take the risk to melt your headlights?

Cheers

AP

The housings will probably be fine. The connectors on the other hand though might not be.

 

I've been running 100w H3 bulbs on my SVX for a while now and the connectors appear to be just fine. Maybe I'm just lucky. I'm going to swap to HID's anyway.

Having run, 100W bulbs for three decades now, here are some suggestions:

 

The grease allows for better contact with the connector and lowers the heat generated there. The tipoff that it is not working any longer (or you have a bad connector) is that the plastic portion of the connector will turn brown and then black due to the excess heat generated. The next thing that happens is that headlamp will fail.

 

Now understand what you're doing with the additional wattage: you are drawing more current through the wiring and switches which were installed in the car during manufacture. Watts divided by volts equals current: 60W draws 5 amps; 100W draws roughly 8.4 amps. Over time this will increase the chance of failure with anything in the headlamp circuit.

 

If the car was over designed, the wiring, connectors, switches, etc. would likely handle the extra current. I'm sure the bean counters at Fuji Heavy Industries did not over design the lighting system.

 

So what to do? Check out rally accessory places; not Schmucks or the like, but a true rally accessory shop (e.g. Competition Limited in Michigan or Primitive Racing in Oregon or any other place you can google). I bought a headlamp harness with heavier wiring, relays and fuses to handle the extra current and installed it in my car.

 

Oh, did I not mention fuses in the original wiring of your car? Hopefully, the original fuses will carry the extra current. Make sure you bring spares. No, you don't increase the size of your fuses to handle the extra current; they are there to prevent the wiring from going up in smoke in cause of overload.

 

Do the right thing, install a heavy duty wiring harness and get full advantage of all that extra brilliance in your lighting without having something crucial fail when you need it most.

 

By the way, see my comment about heavy duty connectors in my reply to Manarius.

Edited by edrach

The housings will probably be fine. The connectors on the other hand though might not be.

 

I've been running 100w H3 bulbs on my SVX for a while now and the connectors appear to be just fine. Maybe I'm just lucky. I'm going to swap to HID's anyway.

I installed a heavy duty wiring harness, relays, and fuses for my headlamps when I went with the high wattage bulbs. Over the years, the only failure I've had with the system is that I have to replace the connectors every four or five years.
I installed a heavy duty wiring harness, relays, and fuses for my headlamps when I went with the high wattage bulbs. Over the years, the only failure I've had with the system is that I have to replace the connectors every four or five years.
Yeah, going to heavy duty wiring is really the only option when it comes to increasing wattage.

Higher wattage (more lumens) is nice, but remember that headlights are regulated at 55w for highway use.

Higher wattage (more lumens) is nice, but remember that headlights are regulated at 55w for highway use.
That's true, but the higher wattage bulbs are available in many types: 100/90 and 100/45 are the most common; I use the 100/45 since the low beams are the legal wattage and I'm not using the highs when I have on-comming traffic. They are also less strain on the wiring since low beam will not exceed the car's wiring specs.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.