H4 vs 9003: Which One Should You Use?

There has been much discussion over the interchangeable use of the H4 headlight with a 9003 headlight.

While they are technically interchangeable, US laws have interfered with the H4 use in US cars.

Let’s take a look at these bulbs to decide the best use for 9003 vs. the H4 bulb.

What’s an H4 bulb

The H4 bulb is a double filament /double beam halogen headlight used for motorcycles and offroad vehicles (race cars). It is not used as a headlight in the US as it is a high-beam light whise tolerance is too high.

What’s a 9003 bulb

The 9003 bulb is a double filament/ double beam headlight used in US cars. It serves as a high-beam and low-beam headlight that gives the driver two headlights in one.

H4 vs. 9003: Their Differences

These bulbs have a double filament, the same outer housing, and a three-prong connector. Both are considered HB2 bulbs.

A quick look

Comparing factors	H4	9003
Light output	High	Low
Night driving capability	Low	High
Brightness	High	Low
Lumens	More	Less
Light Color	White, blue, yellow, or violet	Blue or white
Energy consumption	Higher	Lower
Level of tolerance	Can affect the vision of oncoming drivers	Do not affect the vision of oncoming drivers
Base	Shorter third prong	All prongs have the same length
Durability	High	Low
Compatibility	Compatible with both H4 and 9003 housings	Only fits 9003 housing
Price	$8 (motorcycle)	$6 (car)
Use restrictions in the US	Only allowed for motorcycles	Only allowed for cars

Light Output

H4 is a high output headlight.

9003 is a bright headlight that is not as bright as an H4 headlight. The light’s angle is perfect for night driving.

Types of Filament

H4 has a dual filament.

9003 has a dual filament.

Brightness of Headlamp

H4 has more lumens that makes it the brighter of the two bulbs. These bulbs give off white, blue, yellow, or violet light that is exceptionally bright.

9003 has fewer lumens than the H4, resulting in a dimmer bulb that gives off a blue, white light that is bright but not as bright as an H4 bulb.

Consumption of power

H4’s higher output uses more energy; the amount is insignificant.

9003 use less energy, but the use is barely less than the H4.

Level of Tolerance

Tolerance is based on the “Dazzle Zone,” or the area where the top of the headlights will hit the diver’s vision in oncoming traffic.

H4 is too bright; if it is not perfectly seated in the harness, it can shift and hit the dazzle zone of oncoming travelers.

9003 is set low enough not to affect drivers’ vision in oncoming traffic.

Base

The bases are entirely different, making them non-compatible in their use.

H4’s base is three-pronged, with the third prong shorter than the other two tabs.

9003’s base is three-pronged, with all prongs being the same length.

Durability

The vibration toleration of these bulbs is not significant enough to make a decision in purchasing the bulbs. No facts back up the vibration myth at this time.

H4 is said to be more durable due to withstanding vibrations better than the 9003.

9003 Less durable as it does not tolerate vibrations as the H4.

Compatibility

Both have a three-prong connector; the H4 has one smaller connector, whereas the 9003’s has three same-size connectors.

H4 is compatible with both H4 and 9003 housings.

9003 only fits 9003 housing, does not fit H4 housing.

Pricing

A Hella single bulb on Amazon is priced as follows:

H4 is $7.86 (motorcycle).

9003 is $5.81(car).

Blindness to Oncoming Traffic

H4 is blinding to oncoming traffic.

9003 is not blinding to oncoming traffic.

Legality in the US

H4 is legal in the US only for motorcycles.

9003 is legal in the US in cars only.

Availability

H4 is available in the US as a motorcycle headlight and in Europe for off-road vehicles.

9003 is available only as a car headlight in the US.

Where to use H4 bulbs

As a motorcycle headlight in the US, in Europe, they can be used in both motorcycles and racing cars.

Where to use 9003 bulbs

As headlight in the US.

Halogen H4 vs. LED H4

Halogen H4

Pros

Cheaper than an LED
Bulb is easier to find

Cons

Creates 5 X more heat than a LED
Pulls more current
Shorter Bulb life

LED H4

Pros

Produces less heat than a halogen
Pleasing to the eye on the mororcycle or race car
Uses less current
Saves 30% more energy yet uses 2X more lumens
Converts light into energy 6x more efficiently
Can save a minimal amount of fuel
Long bulb life
High durability

Cons

Cost 3X more than a halogen bulb
Not as available as a halogen bulb