G4 LED Landscape Lighting Bulbs: 2.5W vs 3.5W, 2700K vs 3000K

A G4 replacement lamp may look simple, but there are several things to confirm before ordering: the fixture must use a G4 bi-pin base, the lamp wattage must stay within the fixture rating, the lamp must physically fit inside the housing, and the voltage must match the low-voltage system.

Total Light's current G4 LED family is available in four combinations: 2.5W or 3.5W and 2700K or 3000K. This guide explains how those choices affect the lighting result.

G4 LED Options at a Glance

All four current options are designed for compatible 9V–15V AC/DC low-voltage systems and use a G4 bi-pin base.

Step 1: Confirm the Fixture Uses a G4 Bi-Pin Lamp

Do not choose a replacement by appearance alone. Confirm that the fixture is designed for a replaceable G4 bi-pin lamp.

Total Light G4 lamps are used in compatible fixtures such as certain:

• path lights
• deck lights
• wall-wash fixtures

Check the individual fixture specifications before ordering because not every landscape-lighting fixture uses the same lamp base.

Step 2: Check the Fixture's Maximum Lamp Wattage

The replacement lamp must remain within the wattage allowed by the fixture. A G4 socket alone does not prove that every G4 lamp wattage is appropriate.

If the fixture is rated for both current Total Light options, the choice becomes a lighting-design decision:

• 2.5W: 185 lumens for a lower-output effect
• 3.5W: 265 lumens when additional output is desired

Also include the selected lamp wattage when calculating the connected load on the landscape-lighting transformer.

2.5W vs 3.5W G4: Which Should You Choose?

The 3.5W lamp is the higher-output option in the current Total Light G4 family. The 2.5W lamp uses less power and produces a lower light level.

When 2.5W Can Be a Good Starting Point

• path lights where a softer pool of light is preferred
• closer fixture spacing
• deck or accent locations that should not dominate the scene
• projects where several fixtures work together to create layered light

When 3.5W Can Be a Good Starting Point

• compatible fixtures where more light output is needed
• wider or more open path-light layouts
• wall-wash or accent applications that need additional illumination
• locations where the 2.5W option does not create the desired nighttime effect

These are starting points, not rigid placement rules. Fixture design, shade geometry, mounting height, spacing, surrounding surfaces, and ambient light all affect the visible result.

2700K vs 3000K G4 Color Temperature

Color temperature describes how warm or neutral the light appears. It does not determine brightness by itself.

• 2700K: warmer, slightly more golden light
• 3000K: slightly cleaner, more neutral warm white

2700K can pair naturally with brass fixtures, warm stone, brick, wood, and traditional landscapes. 3000K can complement lighter masonry, stucco, painted surfaces, and designs where a slightly cleaner warm-white appearance is preferred.

For the full design comparison, read 2700K vs 3000K Landscape Lighting.

Brightness and Kelvin Are Separate Choices

A common replacement mistake is assuming 3000K will automatically look brighter than 2700K. The current Total Light G4 specifications make the distinction clear:

• both 2.5W variants are listed at 185 lumens
• both 3.5W variants are listed at 265 lumens

Choose 2.5W vs 3.5W for the output level, then choose 2700K vs 3000K for the color appearance.

Check Physical Clearance Inside the Fixture

A replacement lamp also has to fit inside the fixture without interfering with the lens, housing, gasket, or other components.

Before ordering:

1. confirm the fixture uses a G4 bi-pin socket
2. confirm the permitted lamp wattage
3. check the available internal clearance
4. confirm the fixture operates within the lamp's compatible voltage range

Do not force a lamp into a housing simply because the pins fit the socket.

Voltage Compatibility: 9V–15V AC/DC

The current Total Light G4 lamp family is specified for compatible 9V–15V AC/DC operation, with 12V identified as the recommended operating voltage for the longest listed life.

That operating range does not eliminate the need to design the landscape-lighting system correctly. Wire length, load, conductor size, connections, and transformer tap selection affect the voltage that actually reaches the fixture.

See the landscape-lighting wire-gauge guide and transformer guide for the electrical side of the system.

Replacing One G4 Lamp in an Existing System

When replacing a single failed lamp among several nearby fixtures, match the existing specifications whenever the original lighting effect was intentional.

Check:

• G4 base
• wattage
• color temperature
• voltage compatibility

If one 3000K lamp is installed in a row of otherwise matching 2700K path lights, the color difference may be obvious after dark even though every fixture operates normally.

Replacing Several Older Lamps at Once

If several lamps are being replaced as part of a system refresh, use the opportunity to verify the entire zone rather than automatically copying an old setup.

You may decide to:

• keep the same wattage and Kelvin for consistency
• move from 2.5W to 3.5W in compatible fixtures where more output is actually needed
• standardize mismatched color temperatures
• reduce output in an over-lit area

Any wattage change should be reflected in the total transformer-load calculation.

G4 Lamps in Path Lights

In compatible Total Light path lights, the fixture shade and stem height shape the way the G4 lamp illuminates the ground.

Do not use lamp wattage as a substitute for proper fixture spacing. A higher-output lamp may create brighter hot spots rather than solving a poor layout. Start with the path-light design, then choose the compatible lamp output that supports it.

Use Landscape Path Light Spacing & Placement for the full layout process.

G4 Lamps in Wall-Wash Fixtures

The TL-AL100-CB Classic Brass Wall Wash uses a replaceable G4 lamp. In that application, the fixture distribution and aiming determine how broadly the light reaches the surface, while the lamp wattage affects the light level and Kelvin affects the appearance.

See Wall Washing vs Wall Grazing for positioning guidance.

Dimming Compatibility

The current Total Light G4 listing identifies the lamps as dimmable with compatible Lutron magnetic dimmers. Dimming should be considered at the system level: confirm compatibility among the lamp, fixture, transformer, and control before planning around dimming.

Rated Life and Construction

The current product specifications list:

• Rated life: 25,000 hours
• CRI: 80+
• Pin material: stainless steel
• Body style: silica-gel-style construction with UV inhibitors

Rated life is a product specification, not a promise that every lamp will operate for the exact same number of hours in every installation. Operating voltage, heat, fixture environment, switching, and other system conditions can affect real-world service life.

Bulk Packs for Matching Project Quantities

Matching 25- and 50-count bulk packs are available for all four current Total Light G4 configurations. Bulk packs can make it easier to maintain one wattage and color temperature across a larger path-light or fixture installation.

Browse the bulk-pack LED lamp collection for project quantities.

Common G4 Replacement Mistakes

• Matching only the pin base. Also verify wattage, voltage, and physical clearance.
• Using Kelvin as a brightness setting. Choose wattage/output and color temperature separately.
• Installing a higher-wattage lamp without checking the fixture rating.
• Mixing 2700K and 3000K accidentally in one visible zone.
• Ignoring transformer load after changing several lamp wattages.
• Trying to correct poor spacing with a brighter lamp. Fixture placement may be the real issue.

Frequently Asked Questions

What is the difference between the Total Light 2.5W and 3.5W G4 bulbs?

The 2.5W option is listed at 185 lumens, while the 3.5W option is listed at 265 lumens. Choose only a wattage that is compatible with the fixture.

Is 2700K or 3000K better for G4 path lights?

Neither is universally better. 2700K is warmer and more golden; 3000K is a slightly cleaner warm white. Choose the appearance that fits the surrounding materials and nearby exterior lighting.

Can I replace a halogen G4 lamp with an LED G4 lamp?

Only when the fixture, socket, physical clearance, voltage, and electrical system are compatible with the replacement LED lamp. Do not assume every G4 halogen installation accepts every G4 LED replacement without checking the equipment specifications.

Can I mix 2.5W and 3.5W G4 lamps on the same transformer?

They can be used within a compatible low-voltage system when each fixture supports the selected lamp and the total connected wattage stays within the properly sized transformer system. Include the actual wattage of every lamp in the load calculation.

Can Total Light G4 lamps be dimmed?

The current product listing identifies them as dimmable with compatible Lutron magnetic dimmers. Confirm the complete lamp, transformer, and control combination before installation.

Match the Fixture First, Then Choose Output and Color

The right G4 replacement starts with compatibility. Confirm the base, fixture wattage limit, physical fit, and voltage. Then choose 2.5W or 3.5W for the desired output and 2700K or 3000K for the desired color appearance.

Shop the Total Light G4 LED Low-Voltage Bulb, browse all LED lamps, or use the complete landscape-lighting planning guide when selecting lamps for a new system.