Automotive · Head-to-head
Diode Dynamics SL2 Pro LED (H11/H8/H9) vs GTR Lighting Ultra 3 LED (H11/H9/H8)
Which should you buy? Our verdict on both, pulled from our full The Best LED Headlight Bulbs: 4 Compared (and One to Skip) comparison.
The Diode Dynamics SL2 Pro is the safest honest upgrade: accurate chip placement, real output, and a beam that stays controlled in a projector. Want more light? The GTR Lighting Ultra 3 is the step up, if it clears your dust caps.
Diode Dynamics SL2 Pro LED (H11/H8/H9)
Buy itThe bulb to beat: honest output, filament-accurate chips, and a beam that behaves in a projector.
- Chip layout aimed at keeping the beam focused in a projector instead of scattering
- Measured output of 2400 lumens per bulb, with an integrated sealed cooling fan
- Limited lifetime warranty stated on the maker page
- Not DOT compliant for headlights in the USA; the maker lists fog use as the legal on-road application
- Premium price for a plug-in bulb
GTR Lighting Ultra 3 LED (H11/H9/H8)
Buy itA high-output pick that aims to stay disciplined in a projector.
- High output for a plug-in LED
- Chip layout aimed at keeping the pattern tight for the light it makes
- Waterproof build; check the maker page for current warranty terms
- Large heatsink and fan can be a tight fit under some dust caps
- Check street legality for your market before fitting
Side by side
The 6 criteria below are the ones our full comparison judged every product on, narrowed to these two.
| Diode Dynamics SL2 Pro LED (H11/H8/H9) Our pick | GTR Lighting Ultra 3 LED (H11/H9/H8) | |
|---|---|---|
| Our verdict | Buy | Buy |
| Best for | Anyone with projector headlights who wants a clean, honest upgrade from a company that stands behind it. | Projector owners who want maximum light and will check clearance before buying. |
| Price tier | $$$ · premium | $$$$ · flagship |
| Beam pattern & cutoff | Tight, projector-friendly pattern | Very good for its high output |
| Chip placement (filament accuracy) | Chips laid out for a projector beam | Dual-sided, filament-accurate |
| Honest real-world output | Strong and accurately rated | High |
| Color temperature | ~6000K cool white | Balanced white |
| Cooling & reliability | Integrated sealed fan; limited lifetime warranty | Active fan; check maker warranty |
| Legality / intended use | Not DOT compliant for headlights in the USA | Check street legality for your market |
Which one is right for you?
Pick the Diode Dynamics SL2 Pro LED (H11/H8/H9) if
anyone with projector headlights who wants a clean, honest upgrade from a company that stands behind it.
Know before buying: not DOT compliant for headlights in the USA; the maker lists fog use as the legal on-road application.
Pick the GTR Lighting Ultra 3 LED (H11/H9/H8) if
projector owners who want maximum light and will check clearance before buying.
Know before buying: large heatsink and fan can be a tight fit under some dust caps.
The bottom line
Our overall pick is the Diode Dynamics SL2 Pro LED (H11/H8/H9) - The bulb to beat: honest output, filament-accurate chips, and a beam that behaves in a projector. Choose the GTR Lighting Ultra 3 LED (H11/H9/H8) instead if projector owners who want maximum light and will check clearance before buying.
Want the full picture, including the other options we compared and the popular one we'd skip? Read the complete The Best LED Headlight Bulbs: 4 Compared (and One to Skip).