How to Check Your Spare's Pressure (Donut Spares Need 60 PSI)
It’s 8:15 p.m. on a humid Saturday night in South Beach, and you’re pulling over to the parking lot of a beachfront restaurant because the TPMS light on your dash is flashing red. The air outside smells of salt and sunscreen, and the streetlights cast a yellow glow on the wet asphalt. You reach for the spare tire in the trunk, wondering if it’s ready to keep you rolling until you can get a full-size replacement.
What pressure should a donut spare have?
Unlike a full-size tire, a donut spare is a compact, low-profile unit that carries a higher load for a short distance. Because of its thinner sidewall, it can overheat quickly if underinflated. Tire manufacturers and the U.S. Department of Transportation recommend 60 PSI for a donut spare. This pressure keeps the tire’s bead seated on the rim and prevents the sidewall from flexing too much while you’re driving.
Why does a donut spare need 60 PSI?
When a spare runs at a lower pressure, the sidewall can bulge. That bulge increases rolling resistance and can cause the tire to overheat, especially on the hot, humid roads of Miami‑Dade County. Overheating can lead to a blowout or a loss of traction in sudden turns. Maintaining 60 PSI keeps the tire’s shape stable and ensures it can handle the 10–15 mph speeds you’ll be traveling while you head to a shop.
How do I check the pressure on my spare?
- Locate the valve stem on the spare’s rim. It’s the small metal or rubber nub on the outer edge.
- Press a tire gauge firmly against the stem. A quick squeeze should give you a stable reading.
- Compare the reading to 60 PSI. If it’s lower, add air.
- After inflating, press the gauge again to confirm you’ve reached 60 PSI.
- Close the valve stem and replace any valve cap you removed.
Doing this routine check takes less than a minute and can save you from a roadside emergency.
What tools do I need?
All you need is a reliable tire pressure gauge. Most gas stations have one on a stand, but a portable digital gauge is handy if you’re on the road. If you plan to inflate the spare yourself, a small portable compressor or a regular car air pump will do. Keep the gauge in your glove compartment so it’s always within reach.
How often should I check?
Check the spare’s pressure once a month, or more often if you’re driving in hot weather. Miami’s summer temperatures can drop tire pressure by about 1 PSI per month, so a quick monthly check keeps the spare ready for use. If you notice the TPMS light on your dash, check the spare immediately.
Here’s a quick video that walks through the whole process, from finding the valve stem to using a gauge and inflating the tire.
The video shows a mechanic pulling the spare out of the trunk, removing the valve cap, and placing a digital gauge on the stem. The screen displays the pressure reading and explains that a donut spare should be at 60 PSI. It then demonstrates how to use a portable compressor to add air until the gauge shows 60 PSI, and finally how to re‑cap the valve. The host also points out that you should never drive with a spare at less than 60 PSI because the sidewall may overheat and fail.
When to call us
If your spare’s pressure is below 60 PSI and you can’t get a compressor, or if you notice a spark, a burning smell, or a sudden loss of pressure while driving, (786) 551‑9398 is the number to dial. Flat Tire Miami is available 24/7 for Miami‑Dade County residents, ready to bring a spare or replace a tire on the spot. We’ll help you get back on the road safely and quickly.
When to call us
DIY is great, but some jobs need a pro. If the problem persists, you spot anything dangerous, or you'd rather have an expert handle it, call (786) 551-9398 — Flat Tire Miami serves Miami-Dade County (Mon-Fri 5PM-7AM, Sat-Sun 24H). No pressure, no upsells.