Headlights

Frequently Asked Questions About Semi-Truck LED & Halogen Headlights

Will these headlights fit my specific truck model and year?

Most semi-truck headlights come in standard sizes: 7-inch round (commonly fits Peterbilt 379, Kenworth W900, and older models) and 4x6 or 5x7 rectangular (fits Freightliner, International, Volvo, and newer models). Always verify your existing headlight dimensions before ordering. If you're unsure, remove one headlight and measure the housing diameter or rectangle dimensions. Our product descriptions include specific fitment details, but you can also contact our support team with your truck's year, make, and model for confirmation.

What's the real difference between LED and halogen, and is LED worth the extra cost?

LED headlights typically last 30,000-50,000 hours compared to 500-1,000 hours for halogens, meaning you'll replace halogens 30-50 times before an LED fails. LEDs produce 2-3 times more light output while using 80% less power, reducing strain on your electrical system. The upfront cost is higher (usually $100-300 per LED vs $20-50 per halogen), but most drivers break even within 12-18 months due to reduced replacement costs and fuel savings from lower alternator load. LEDs also provide instant full brightness and better visibility in rain and fog.

How difficult is installation, and what tools or modifications are needed?

Most headlight replacements are plug-and-play and take 15-30 minutes per light. You'll need basic tools: screwdrivers, socket set, and possibly trim removal tools. Halogen-to-halogen swaps are always direct replacements. When upgrading from halogen to LED, some trucks require anti-flicker harnesses or load resistors to prevent dash warning lights or rapid blinking. Sealed beam to LED conversions may need new mounting rings. Always disconnect the battery before installation to prevent electrical damage.

Why do some LED headlights cause interference with my radio or CB?

Cheap LED headlights often lack proper EMI (electromagnetic interference) shielding, causing static on AM/FM radios and CB channels. Quality LEDs include built-in EMI filters and shielding to prevent this issue. Look for headlights that specifically mention FCC compliance or EMI/RFI suppression. If you experience interference after installation, adding ferrite cores to the power wires or upgrading to better-shielded headlights usually solves the problem. Avoid bottom-tier LED brands that don't address EMI in their design.

What beam pattern should I choose, and are these DOT legal?

For on-road use, always choose DOT-approved headlights with proper beam patterns. Low beams should have a clear horizontal cutoff line to prevent blinding oncoming traffic. High beams should project further without the cutoff. Many cheap LEDs scatter light everywhere, which is illegal and dangerous. DOT-approved lights will have "DOT" stamped on the lens. Some states have additional requirements for headlight color temperature (usually 3000K-6000K is acceptable). Off-road or private property use allows more flexibility with beam patterns and brightness.