4×6 vs 5×7 vs 7-Inch LED Headlights for Fleets: Fitment Guide

A 4×6, 5×7, or 7-inch LED headlight must match the headlight system already installed on your vehicle. Shape and lamp count narrow the choice. The lens code, beam function, connector, mounting depth, voltage, and road-use requirements confirm it.

Which LED Headlight Size Should You Order?

Start by looking at the shape and number of headlights on the front of the vehicle.

Do not order by vehicle brand alone. The same truck brand may use different headlight systems across model years, trim levels, body configurations, and factory lighting packages.

4×6 LED Headlights: Best for Four-Lamp Systems

A 4×6 headlight belongs to the rectangular sealed-beam family that measures about 100 × 165 mm. These lights appear on many older heavy trucks, buses, municipal vehicles, service vehicles, and special-purpose equipment.

Most 4×6 applications use four headlights: two outer lamps and two inner lamps. This layout creates the most common ordering mistake in this category. The four lamps may look alike, but they may perform different jobs.

Outer and Inner Lamps May Have Different Functions

For example, H4651 is commonly used as a high-beam lamp with two terminals. H4656 commonly has three terminals and supports both upper and lower beam functions. You can see the function differences in our H4651 vs H4656 vs H4652 guide.

The correct buying decision is to match the code and lamp position. Ordering four units because they share the same dimensions can leave you with the wrong beam function or connector layout.

Where 4×6 Headlights Are Commonly Used

Depending on the year and original system, 4×6 sealed-beam headlights may appear on selected Peterbilt, Kenworth, Freightliner, and other heavy trucks, older Class 8 trucks, municipal service vehicles, buses, shuttle vehicles, and four-headlight commercial vehicle conversions.

These examples help you identify the headlight family. They do not confirm fitment for every model year. Record the code molded into each existing lamp. If the inner and outer lamps show different codes, keep them as separate SKUs in your fleet parts list.

Compare LOYO’s 4×6 LED sealed-beam headlights after confirming the high-beam and low-beam positions.

5×7 and 7×6 LED Headlights Are the Same Size Family

The terms 5×7 and 7×6 usually describe the same rectangular sealed-beam format. Many products in this family also use the H6054 reference.

The trade names do not describe the exact outer dimensions. A standard lamp in this family is closer to 200 × 142 mm. Product listings may call it 5×7, 7×6, or H6054.

Use the molded lamp code whenever possible. It gives you a more reliable reference than a rough tape measurement.

Why 5×7 Headlights Are Easier to Manage

Most 5×7 systems use one headlight on each side of the vehicle. Each lamp provides both low and high beam. A vehicle normally needs two matching lamps instead of four position-specific units. This can make purchasing, workshop installation, and spare inventory easier.

Common applications include selected older commercial vans, delivery and service vehicles, classic pickup trucks still used for commercial work, utility vehicles, municipal maintenance vehicles, and trucks using H6054-style sealed beams.

Year and trim still matter. Check the existing lamp code and housing before adding a vehicle to your approved fitment list.

LOYO offers 5×7 and 7×6 H6054 LED headlights with different beam, DRL, turn signal, and certification options. Availability varies by model.

7-Inch Round LED Headlights: Best for H6024-Style Housings

A 7-inch round headlight measures about 178 mm across the lens. It is commonly used as a complete high/low-beam lamp, with one headlight on each side of the vehicle.

This format is associated with H6024, 6014, 6015, and PAR56-style sealed-beam applications.

You may find 7-inch round headlights on selected Class 6 and Class 7 vocational trucks, older utility and maintenance vehicles, municipal service vehicles, shuttle buses, agricultural service vehicles, industrial support vehicles, and special-purpose vehicle conversions.

A 7-inch lens diameter does not guarantee a direct fit. Check the bucket, retaining ring, connector, and depth behind the lamp.

Why Vehicle Year and Fleet Configuration Still Matter

Two vehicles from the same manufacturer may use different headlights because of model year, trim, factory options, or later fleet modifications.

A truck may also have a replacement bucket, custom bezel, snowplow frame, service-body wiring, or other equipment added during an earlier upfit. These changes can affect mounting space and wiring.

Check the headlight installed on the vehicle instead of relying only on the make and model. Record the lamp code, connector, mounting depth, voltage, and beam function for each vehicle group.

Browse the LOYO 7-inch round LED headlight range after checking the housing and wiring on your vehicle.

Seven Checks That Confirm Fleet Headlight Fitment

Headlight size gets you into the correct product family. These checks decide whether the lamp will install and work correctly.

1. Read the Code on the Existing Lamp

Look near the edge of the old lens for a molded or printed code. Common examples include H4651, H4652, H4656, H4666, H6054, and H6024. Record the full code. Do not rely on a warehouse label that only says “rectangular headlight” or “round headlight.”

2. Confirm the Number of Lamps

Count the total headlights on the vehicle. A four-lamp 4×6 system may require separate inner and outer units. A two-lamp 5×7 or 7-inch system usually uses one dual-beam lamp on each side.

This difference also changes the order quantity.

That does not mean you must replace every lamp at once. It shows why vehicle count alone is not enough when you request a quote.

3. Check the Beam Function

Confirm whether each position needs low beam, high beam, combined high and low beam, daytime running light, turn signal, or position light.

If the replacement includes DRL or turn signal functions, the main headlight connector may not power those extra functions. Additional wires may need to connect to the vehicle’s DRL, position-light, or turn-signal circuit.

4. Photograph the Connector

Many sealed-beam LED headlights use a three-pin H4-style connection. Some vehicles use a different factory connector or pin arrangement.

A connector that fits physically can still have a different pin arrangement. Test high beam, low beam, and ground before approving a fleet-wide installation.

5. Measure the Mounting Space

Measure the lens and the available depth behind the headlight. Check the rear housing depth, connector clearance, retaining ring, mounting bucket, bezel opening, nearby wiring, brackets, and clearance around fleet-installed equipment.

LED headlights often have a deeper rear housing than old glass sealed beams because the housing must hold the driver and heat sink. A front face that fits does not prove that the back of the lamp will clear the bucket.

6. Confirm Vehicle Voltage

Record whether the vehicle uses a 12V or 24V electrical system. Some LED headlights accept a wide input-voltage range. Others do not. Use the voltage range shown on the exact product specification, not the range from a different model in the same category.

A fleet that includes light-duty vans and heavy trucks may need more than one electrical configuration.

7. Check the Operating Market

Road-use requirements differ between markets.

For the United States, replacement headlamps must meet the applicable requirements of FMVSS No. 108. A DOT symbol represents the manufacturer’s certification of compliance. It is not an individual approval issued by the Department of Transportation, as explained by NHTSA.

For E-Mark markets, check the approval number, lamp function, beam direction, and certificate for the exact product. A certificate from another headlight model does not cover every item in a supplier’s catalog.

For commercial fleets in the United States, required lamps must remain operable. FMCSA lists inoperative required lamps under 49 CFR 393.9 in its vehicle lighting guidance.

Measure the Headlight Without Measuring the Bezel

A trim bezel can make the lamp look larger than it is. Measure the lens or the removed lamp.

Measurements help when the code has worn away. If the code is readable, use both.

Which Size Works Best for Different Fleet Types?

Build a Fleet Headlight Fitment List

A spreadsheet or maintenance record should include more than the vehicle name.

This record gives your maintenance team a repeatable replacement process. It also gives the supplier enough information to recommend the correct sample.

Test One Complete Vehicle Configuration First

Do not approve a bulk rollout from a product photo or dimension drawing.

Test at least one complete vehicle for every exact configuration in your fleet. A 4×6 four-lamp truck, a 5×7 commercial van, and a 7-inch utility vehicle count as three configurations, even if they come from the same manufacturer.

For a four-lamp 4×6 system, test a complete four-piece set. Testing one lamp does not confirm the inner and outer positions.

LOYO can supply sample units at wholesale pricing for fitment and performance checks before a larger production order.

Beam Pattern Matters More Than a Large Lumen Number

Lumen output describes the amount of light produced. It does not show where that light reaches the road.

Two headlights with similar lumen claims can produce different results because the reflector, projector, cutoff, lens, LED position, and headlight aim control the beam.

For fleet use, inspect the low-beam cutoff, light distribution across the lane, dark spots, foreground brightness, high-beam reach, glare above the cutoff, and left and right beam consistency.

A focused beam helps the driver use the available light. A scattered beam can look bright near the vehicle while leaving the distance ahead poorly lit.

Headlight aim must be checked after installation. Replacing the lamp can change the beam position even when the new unit fits the original mounting points. For a broader comparison of the light sources, see LED vs halogen headlights.

How to Compare Suppliers for a Fleet Program

A fleet headlight supplier should be able to confirm the product beyond its outside dimensions. View TOP 10 LED headlight suppliers for truck and fleet.

Ask the supplier to mark the recommended SKU against each vehicle group in your fleet list. This makes gaps visible before you place the order. A vague “universal fit” statement is not enough for a fleet rollout.

When Does a Custom Headlight Solution Make Sense?

Use an existing 4×6, 5×7, or 7-inch headlight when it meets your fitment, voltage, beam, certification, and branding requirements. This is usually the fastest path for a trial order or standard replacement program.

Consider OEM or ODM development when you need:

LOYO supports custom development for vehicle manufacturers, fleet upfitters, brand owners, and high-volume distributors. Contact our technical team to discuss project specifications, minimum order quantities, and tooling timelines for your custom headlight project.

Frequently Asked Questions