Type "train horn" into a search bar and within two clicks you'll hit the phrase "spare tire delete." It sounds like a required step. It isn't. Compressor-and-tank kits need somewhere to hang a steel tank, and on a pickup the spare tire well is the biggest open space under the truck. A battery-powered train horn has no tank, so the question never comes up. Here is what a spare tire delete involves, what you give up, and how to keep your spare and still run a 150 dB horn.
What a "Spare Tire Delete" Actually Is
A spare tire delete is a bracket that replaces your factory spare tire. You drop the spare, and the metal hanger that held it is repurposed to lift and secure a steel bracket carrying an air tank, a compressor, and the trumpets. HornBlasters sells the bracket alone for $353.99 under the slogan "You can't honk a Spare!" and builds entire kits around it.
The numbers on those kits tell you why the spare has to go. Their standard Spare Tire Delete Kit pairs a 2-gallon, 6-port air tank with a four-trumpet Shocker XL horn whose trumpets measure 19.5, 16.25, 14.75, and 12.75 inches. The Stealth version's assembled package measures 27 inches long by 21 inches wide, stands 8 inches tall with a 2-gallon tank or 12 inches with a 5-gallon tank, and weighs 50 or 57 pounds respectively. There is no other spot on a stock pickup where a 27-by-21-inch, 50-pound assembly fits without fabrication.
Fitment is listed as "most full-size and mid-size pickups," with a note that 2020 to 2021 Chevy and GMC 1500 and 3500 trucks "will require some modification to the mounting point." Install time is quoted at 3 to 4 hours, positioned as the fast option next to 6 to 8 hours for a conventional frame-mounted install. The dual-tank version, two 2-gallon tanks for 4 gallons total, is described as about 3 hours of assembly and wiring.
What You Give Up When You Delete the Spare
The spare is the one part of your truck you hope to never use, which makes it easy to sacrifice on paper. AAA's 2017 study on spare tires found that 28 percent of 2017 model-year vehicles shipped without one, and that in the previous year AAA responded to more than 450,000 members who had a flat and no spare to put on. The same study noted that tire-inflator kits "cannot provide even a temporary fix" for sidewall damage or blowouts, which are exactly the failures you get on gravel roads, job sites, and trails.
Train horn buyers feel that more than most. Off-roaders, hunters, ranchers, and boat owners towing to a ramp are the drivers most likely to be far from a tow truck when a tire lets go. Some air-kit owners throw the spare in the bed or buy a swing-out carrier, but both eat space or add cost on top of a kit that already starts at $999.99.
There is also the ongoing upkeep. An air tank is a pressure vessel. HornBlasters' own air tank guide recommends inspecting tanks monthly for corrosion, draining condensation regularly because moisture "can cause internal corrosion, reduce the tank's efficiency, and lead to premature failure," and relying on a safety blow-off valve. A tank hanging in a spare tire well takes the full blast of road spray, salt, and gravel.
Why a Battery Train Horn Doesn't Need the Space
A battery train horn removes the tank from the equation entirely. The compressor, valve, and receiver live in one power-tool-style housing, and a cordless tool battery slides onto the bottom. Hit the remote and the compressor feeds the trumpets directly. No reservoir, no pressure switch, no 12-volt wiring, no 50-pound bracket. The horn arrives assembled, and setup is quoted at under one minute: charge the battery, click it in, pair the remote.
Our loudest version is the Extreme Series Train Horn for Milwaukee® 18v Battery. It is rated at 150 dB measured at the trumpet mouth at one meter, runs on any Milwaukee® M18™ pack from 1.5Ah to 12Ah with no adapter, and ships with a 160-foot wireless remote, a universal mount bracket with rubber isolators and stainless hardware, and a pre-cut reinforced PU air-line set. A long-range remote upgrade extends coverage up to 2,000 feet. The compressor uses a sealed head, so there is no air loss between blasts, and a thermal cutoff protects the motor during extended use.
The same design is available for DeWalt® 20V MAX™, Ryobi® ONE+™, Makita® LXT™, Bosch®, Ridgid®, and the hardware-store battery brands, so it takes the packs you already own. Because it is one compact unit rather than a tank, compressor, and trumpet array spread across the frame, it mounts where a tank never could, and your spare stays where the factory put it.
Spare Tire Delete Kit vs Battery Train Horn: The Trade-Offs
| Factor | Spare Tire Delete air kit | Battery train horn |
|---|---|---|
| Spare tire | Removed; bracket takes its place | Stays in the factory carrier |
| Assembled size | 27 x 21 x 8 to 12 in (Stealth kit) | One power-tool-sized housing plus trumpets |
| Assembled weight | 50 to 57 lb before compressor wiring | Light enough to carry in one hand |
| Install time | 3 to 4 hours (kit claim); 6 to 8 for frame mounts | Under 1 minute to operate; mounting is optional |
| Vehicle wiring | Compressor, pressure switch, relay, valve | None; runs on the tool battery |
| Honk time | 3 to 5 sec (2 gal); 10 to 12 sec (5 gal) per fill | Blast as long as you hold the button, limited by motor heat |
| Refill wait | 35 sec to 1 min 33 sec from 110 to 150 PSI, depending on compressor | No tank, no refill |
| Maintenance | Monthly tank inspection, moisture drain, blow-off valve | Charge the battery |
| Starting price | $999.99 kit; $353.99 bracket alone | Dual models start under $200; Extreme Series is the premium tier |
The honk-time row is the air kit's strongest argument and its biggest compromise at once. A 2-gallon tank gives you 3 to 5 seconds, then the compressor needs 35 seconds to a minute and a half to catch up. A 5-gallon tank stretches that to 10 to 12 seconds but adds 7 pounds and 4 inches of height. A battery horn has no reservoir to drain, so the next blast is ready the instant you release the button.
Where to Mount a Battery Horn on a Truck That Still Has Its Spare
With no tank in the plan, a pickup has plenty of options. The included bracket fits standard roll bars, bed rails, and most marine handrails, and no-drill methods cover the rest.
- Bed rail or bed-rail stake pocket. The most popular truck mount. The trumpets get clear air and the battery is within reach. Bed rails are the first recommendation in our train horn mounting guide, which also covers the clamp sizes and stainless hardware to use.
- Under the rear of the bed, on the frame rail next to the spare. The hidden option. The horn bolts or clamps to the frame rail beside the spare carrier, aimed rearward. Keep 2 inches of clearance around the housing's vent openings for motor cooling and stay 12 inches from any fuel component. Our guide to hidden and stealth mounting spots walks through the under-bed layout in detail.
- Factory bolt points and magnets. Seatbelt anchors, bumper bolts, and existing frame holes give you a bolt-on mount with zero new holes. On steel, a magnet rated for 100 pounds or more of pull works for semi-permanent use with a tether. Both are covered in our no-drill mounting guide.
- No mount at all. Plenty of owners keep the horn behind the seat and grab it when needed. The remote fires it from the driver's seat either way.
The full setup is covered in how to install a battery train horn. None of the steps involve a jack, a spare tire hanger, or a wiring harness.
When a Spare Tire Delete Still Makes Sense
There are two honest reasons to go the air-kit route. The first is onboard air. A tank and compressor double as a tire inflator and can run a small air tool, which is why HornBlasters sells tire-inflation kits alongside the brackets. If you air down for sand and air back up at the trailhead, a tank earns its space, though you are then betting your recovery on a compressor and a plug kit rather than a spare.
The second is sustained honk time. A 5-gallon tank delivers a continuous 10 to 12 second blast. A battery horn's compressor runs the whole time you hold the button, so it is built for short bursts, with a thermal cutoff if you lean on it too long. For a warning blast, a boat ramp, or a moose on the trail, short bursts are what you want. For a 12-second train chord at a car show, the tank wins.
If neither applies to you, the bracket solves a problem you don't have. For the full cost breakdown, see battery train horn vs compressor and tank kit.
FAQ
Do I have to remove my spare tire to install a train horn?
Only if you install a compressor-and-tank kit on a bracket designed to replace the spare. Air kits can be frame-mounted with the spare retained, but that is the 6 to 8 hour install. A battery train horn has no tank, so the spare stays put.
Can I mount a battery train horn in the spare tire well without removing the spare?
Not directly above or below the tire, because the carrier needs room to lower it. Mount to the frame rail beside the carrier, keep 2 inches around the vents and 12 inches from fuel lines, and confirm the spare still drops freely.
Is a battery train horn as loud as a spare tire delete kit?
The Extreme Series is rated at 150 dB at the trumpet mouth at one meter, and quad-trumpet models are rated at 140 dB. The difference is duration, not peak volume: a tank sustains 3 to 12 seconds per fill depending on size, while a battery horn is built for repeated short bursts with no refill wait.
Does a battery train horn need any wiring to the truck?
No. It runs entirely off the cordless tool battery and fires from a wireless remote with a 160-foot standard range or up to 2,000 feet with the long-range upgrade. Nothing connects to the truck's 12-volt system.