Posted 10.23.26 in Tips & Instructions
A glowing tube under the body and color spilling across the pavement: that is the look people mean by neon tube car lights. You can still build it. The real question is which tube goes under your car.
In XKGLOW's lineup, the LED tube fills the slot a neon tube would fill. It keeps the tube shape and puts LED chips where the gas would be. XKGLOW doesn't sell a gas-filled neon kit, so it stands on the LED side of this comparison.
How a Neon Tube Car Light Makes Its Glow
A neon tube is a type of electric discharge lamp. Britannica describes that lamp as a transparent container holding a gas that is "energized by an applied voltage and thereby made to glow."
The neon tube dates to about 1910, when French physicist Georges Claude filled a tube with neon gas. When high voltage reached the two electrodes, one at each end, the tube gave off "a deep red light." Neon signs followed, built from glass tubes bent into words and shapes.
Color comes from what goes inside. Neon itself glows red. Other fillings such as mercury, argon and helium produce other colors, and tinted glass shifts the result: helium in amber glass glows gold. So the color of a neon tube is set by its gas and its glass.
How an LED Tube Lights Up
An LED works on a different principle. Britannica defines it as a semiconductor device that emits light "when charged with an electric current." Most LEDs run at a low voltage, about 2 volts. LEDs are already on cars: Britannica lists car brake lights among their uses.
An LED tube packs a number of those chips into a protective housing. Each tube in XKGLOW's UFO kit carries 18 SMD LEDs inside a reinforced polycarbonate tube with waterproof epoxy.
XKGLOW's XKmax tubes go further, with addressable RGBW LEDs built "for dynamic chasing patterns and flowing dream color effects." The W is a dedicated white LED chip that works alongside the RGB chips.
That is the core difference under a car. A neon tube shows the color it was built with. An LED tube shows the color you pick on a remote or in an app, and an addressable tube can send that color chasing down its length.
Neon Tube Car Lights vs LED Underglow, Side by Side
| Neon tube | XKGLOW LED tube | |
|---|---|---|
| Light source | Gas that glows under an applied voltage | Semiconductor LED chips lit by an electric current |
| Voltage | High voltage across the electrodes at each end | About 2 volts for most LEDs; the XKmax underglow controller takes 12V DC |
| Color | Set by the gas and the glass (neon glows red) | Picked on a remote (UFO kit) or in the XKmax app (XKmax kits) |
| Housing | Glass tube | Impact-resistant IP67 tubes (XKmax underglow kit), IP67 aluminum (ULTRA), reinforced polycarbonate with waterproof epoxy (UFO) |
The LED column also opens up features the table leaves out: chase patterns, music sync and control from your phone. How much of that you get depends on the kit.
Power Under the Car
Where a neon tube runs on high voltage, the XKmax underglow kit feeds its tubes from a controller with a 12V DC input. Each channel handles up to 60 watts, and XKGLOW makes the controller in 2-channel and 4-channel versions.
For the ULTRA, XKGLOW rates each 2-foot tube at up to 14.4 watts. Full kits top out at 146.9 watts for the 5-foot size and 195.8 watts for the 8-foot.
Three XKGLOW LED Tubes That Give You the Neon Look
All three kits use tubes, so the shape stays familiar. Pick by what you want the tube to do.
The UFO Kit: Color on a Remote
Want a tube that glows in the color you choose, with no app to learn? Start with the Underglow LED Accent Light Kit, Million Color UFO with Remote (XK041000).
The base kit packs eight 24-inch tubes for $167.99, list price at the time of writing. A second kit adds four 12-inch tubes for $215.99.
Each tube puts out about 100 to 120 lumens at full brightness. A 24-inch tube can also show two colors at once, split into 12-inch sections, which lets the kit run chasing and glow-wave patterns. The remote picks the preset program, and a music mode syncs the glow to sound with adjustable sensitivity. The listed install time is 1 to 2 hours. There is no app on this kit, so phone control and the DIY theme builder stay with the XKmax kits.
The XKmax Underglow Kit: Color That Moves
For motion, step up to the XKmax LED Underglow Light Kit with RGBW Color Chasing. The underglow-only tier, the Underbody Kit (MX-CAR-STA), lists at $341.99 at the time of writing and pairs a 2-channel controller with eight tubes of 24 inches each.
This is XKGLOW's 5th-gen Bluetooth RGBW system, built as a universal fit for cars, trucks, Jeeps and more. You run it from the XKmax app. Start from 28-plus prebuilt chase themes, or draw up your own in the DIY builder. The glow can follow your music, your vehicle speed or your acceleration. Up to 10 lighting zones run from a single controller.
Connect the 3 sensor wires and the tubes react to your turn signals, brakes and courtesy lights, and the startup mode is programmable. Only the two combo tiers, Interior + Underbody and Interior + Underbody + Wheel, ship with the 4-button key fob. Plan on 2 to 3 hours for the install.
XKmax ULTRA: A Gapless Aluminum Line
If a long, unbroken line of light is the goal, the XKmax ULTRA Aluminum LED Underglow Light Kit with RGBW Color Chasing is built for it.
Its impact-resistant aluminum tubes carry an IP67 rating, and end-to-end connections give a gapless look. Every kit includes two 2-foot tubes for the front and two for the rear. You choose the side tube length: 5, 6, 7 or 8 feet.
XKGLOW puts the ULTRA at 2.7 times the brightness of its standard XKmax car kit. It also uses addressable RGBW LEDs and runs from the XKmax app, with the 4-button key fob as a quick-access option. Plan on a 2 to 3 hour install.
Neon or LED: Which Tube Fits Your Car
Choose neon only if the gas glow itself is the point of the build. That means a genuine gas-filled glass tube, and XKGLOW doesn't make one.
For everything else, an LED tube gives you more to work with. You get color you change on the fly, chase patterns on the XKmax kits, and control from a remote or your phone. Start with the UFO kit for simple color, the XKmax kit for motion and sync, or ULTRA for a gapless aluminum line.
Color and flashing rules on public roads apply to either tube, and our guide to car underglow laws quotes four state codes. For the rest of the car, see XKGLOW's guide to choosing car LED lights. Build yours today.
Frequently Asked Questions
What is a neon tube?
A neon tube is a glass tube with gas inside that glows when a high voltage is applied across electrodes at its ends. Pure neon gives a deep red light. Other gases, and tinted glass, produce other colors. XKGLOW's underglow tubes use LED chips instead of gas.
Is neon light better than LED?
For underglow you want to control, LED does more. An XKmax LED tube changes color from your phone, runs chase patterns and syncs to music. A neon tube's color is set by its gas and glass. Neon is the better pick only when an authentic gas glow is the goal.
How expensive is underglow?
XKGLOW's LED tube underglow starts at $167.99 for the eight-tube UFO kit, at list prices as of this writing. The XKmax Underbody Kit is $341.99, and XKmax ULTRA aluminum kits run $999.99 to $1,179.99, depending on side tube length. Install times are listed at 1 to 3 hours.
