Quick answer: Find the spare tire’s specified cold inflation pressure in your vehicle owner’s manual or tire-information label before adding air. Many compact temporary “donut” spares are specified at about 60 PSI, but your vehicle’s specification is the one to follow. Check the pressure with an accurate gauge, connect an inflator that can reach the required PSI, add air in short bursts, and recheck often. Do not use a visibly damaged spare or one that will not hold pressure.
Key Takeaways
- Use the vehicle manufacturer’s specified pressure for the spare; do not assume every spare uses the same PSI.
- Many compact temporary spares use about 60 PSI, while full-size spares generally follow the vehicle manufacturer’s pressure guidance.
- Check the spare when it is cold, ideally at least once a month and before a long trip.
- Add air gradually and recheck with a tire pressure gauge so you do not overshoot the target.
- Inspect the tread, sidewalls, valve stem, and wheel for damage, and have a spare that repeatedly loses pressure inspected by a tire professional.
- If the spare is a collapsible or inflatable type that is stored deflated, follow the vehicle-specific procedure in the owner’s manual rather than a generic inflation method.
Find the Right PSI for Your Spare Tire
Before you inflate a spare tire, identify the type of spare and find the manufacturer-specified cold inflation pressure. Start with the vehicle owner’s manual and the tire-information label. For a temporary spare, also follow any pressure marking or instructions supplied specifically for that spare.
Do not use the maximum-pressure wording on a normal road tire’s sidewall as a substitute for the vehicle manufacturer’s recommended pressure. Many compact temporary spares are designed to be stored at about 60 PSI, but specifications can vary.
| Spare type | Pressure guidance |
|---|---|
| Compact temporary or “donut” spare | Often about 60 PSI; verify the vehicle-specific specification. |
| Full-size spare | Follow the vehicle manufacturer’s placard or owner’s manual for that wheel-and-tire setup. |
| Collapsible or inflatable spare | Follow the special procedure and inflator instructions in the owner’s manual. |
Use the pressure specified by the vehicle manufacturer for your exact spare tire setup.
Check the spare regularly even when it is stored and unused. NHTSA recommends checking all tires, including the spare, at least once a month when cold. Tires naturally lose air over time, so a spare that looked fine months ago may be too low when you need it.
Gather the Tools You Need
Gather a tire pressure gauge, an air compressor or portable tire inflator, and the vehicle owner’s manual. Make sure the inflator is rated to reach the spare’s required pressure; many temporary spares need substantially more pressure than the vehicle’s regular tires.
You may also want gloves and a flashlight if the spare is stored under cargo or beneath the vehicle. If you are only checking or inflating a stored spare, you normally do not need to jack up the vehicle.
Inspect the valve stem before attaching the gauge. Remove dirt from around the valve so the gauge and air chuck can seat properly, then keep the valve cap in a safe place while you work.
Check Your Spare Tire Pressure
Use a tire pressure gauge when the spare is cold. NHTSA defines a cold tire as one that has not been driven on for at least three hours. A spare that has been sitting in its storage location is normally already cold.
Remove the valve cap, press the gauge firmly onto the valve stem, and read the pressure. Compare the reading with the manufacturer’s specification. If it is low, add air; if it is high while the tire is cold, release a small amount and recheck.
Check the spare at least monthly and before long trips. Michelin notes that tires can naturally lose up to about 1 PSI per month, which is one reason an unused spare can become underinflated over time.
While checking pressure, inspect the tire for cuts, cracks, bulges, punctures, or other damage. If it is damaged or cannot maintain pressure, do not rely on it for emergency driving.
Inflate the Spare Tire Step by Step
- Confirm the target pressure. Use the owner’s manual and vehicle tire-information label, plus any instructions specific to the temporary spare.
- Check the spare while cold. Measure its current pressure with an accurate gauge.
- Inspect the tire and valve. Stop if you see a bulge, deep cut, exposed cord, severe cracking, or other obvious damage.
- Connect the inflator. Seat the air chuck firmly on the valve stem so air is not escaping around the connection.
- Add air gradually. Inflate in short bursts and stop to recheck the pressure frequently.
- Correct an overfill. If a cold spare is slightly above the specified pressure, release a small amount of air through the valve stem and measure again.
- Finish the check. When the pressure matches the specification, disconnect the inflator, recheck once with the gauge, and reinstall the valve cap.
- Store the spare securely. Return it and the tools to their proper mounting or storage locations so they cannot move while driving.
If your vehicle uses a collapsible spare that is stored deflated, do not assume these steps apply. Some designs require the spare to be mounted first and then inflated with a supplied system. Follow the owner’s manual exactly.
Look for Leaks, Damage, or Wear
Pressure is only one part of spare-tire readiness. Inspect the tread, sidewalls, valve stem, and wheel for damage or deterioration. A spare that is cracked, bulged, punctured, badly worn, or repeatedly losing air needs professional attention before you depend on it.
Inspect for Visible Damage
Look for cuts, punctures, bulges, scrapes, cracking, exposed cords, tread separation, and unusual wear. NHTSA advises regular tire inspections and says tires showing physical damage or serious wear should not remain in service.
Also inspect the wheel for severe rust, bends, or damage around the bead area. If you are unsure whether the spare is safe, have a tire professional inspect it rather than relying on a visual check alone.
Check Valve Stem Leaks
Look for cracks, cuts, or deterioration around the valve stem. If the spare loses pressure after being inflated, a simple soapy-water check around the valve can help reveal an obvious leak by forming bubbles.
- Make sure the valve stem is not visibly cracked or damaged.
- Keep the valve area clean and reinstall the valve cap after checking pressure.
- Recheck pressure after inflation if you suspect a slow leak.
- Have repeated pressure loss inspected professionally instead of repeatedly topping up the tire.
Assess Tread and Age
Check the spare’s tread and its DOT Tire Identification Number. The last four digits of the DOT code identify the week and year of manufacture. NHTSA notes that some vehicle and tire manufacturers recommend replacement when tires reach about 6 to 10 years of age, regardless of treadwear, so follow the limits from your vehicle and tire manufacturers.
For a full-size spare, NHTSA uses 2/32 inch as the minimum tread depth at which a tire is worn out. Temporary spares may have different construction and wear indicators, so follow the instructions for that specific spare and use it only as intended.
Age cannot be judged by appearance alone. If the spare is old, damaged, or of uncertain condition, have it evaluated or replaced before an emergency makes it your only option.
Reinstall and Recheck the Spare Tire
If you removed a stored spare only to check or inflate it, return it to its carrier and secure the retaining hardware exactly as the vehicle manufacturer specifies. Recheck the valve cap and make sure tools are stowed safely.
If you are mounting the spare on the vehicle after a flat, follow the vehicle’s tire-changing procedure. Park on a stable, level surface away from traffic when possible, set the parking brake, use the specified jack points, and never place any part of your body under a vehicle supported only by a jack.
Reinstall Spare Correctly
Place the spare on the hub, hand-start the lug nuts, and tighten them in the pattern specified in the owner’s manual. Lower the vehicle as directed, then tighten the lug nuts to the manufacturer’s specified torque with the proper tool.
- Use the correct jack points and wheel-changing procedure for your vehicle.
- Start every lug nut by hand to reduce the risk of cross-threading.
- Tighten the lug nuts in the specified star or crisscross pattern when applicable.
- Use the vehicle manufacturer’s lug-nut torque specification.
- Recheck the spare’s pressure before driving.
Recheck Tire Pressure
After inflation—and again before driving on a mounted spare—verify the pressure with a gauge. Do not rely only on the inflator’s display if you have a separate trusted gauge available.
| Check | Action |
|---|---|
| Pressure below spec | Add air and recheck |
| Pressure at spec | Spare is pressure-ready; still follow its driving limits |
| Pressure drops again | Have the tire, valve, and wheel inspected |
| Visible damage | Do not rely on the spare; seek professional service |
Continue checking the spare monthly. A temporary spare is emergency equipment, so its pressure and condition matter even when it spends most of its life out of sight.
Frequently Asked Questions
How Do You Put Air in a Tire Step by Step?
Find the manufacturer’s recommended cold pressure, remove the valve cap, and check the tire with a gauge. If the pressure is low, attach an air compressor and add air in short bursts, rechecking frequently.
Once the tire reaches the specified pressure, disconnect the inflator, verify the reading again, and reinstall the valve cap. If the tire repeatedly loses pressure, have it inspected for a leak.
What Is the 50/50 Rule for Spare Tires?
The “50/50 rule” is a common rule of thumb for many temporary donut spares: keep speed at or below 50 mph and limit driving to roughly 50 miles. AAA gives similar guidance for temporary spares.
It is not a universal specification. The speed and distance limits printed for your spare or listed in your owner’s manual take priority, and you should repair or replace the normal tire as soon as practical.
How Do You Put on a Spare Tire Step by Step?
Move to a safe, stable location, apply the parking brake, and follow the vehicle’s jacking instructions. Loosen the lug nuts as directed, raise the vehicle at the correct jack point, remove the flat tire, install the spare, and hand-start the lug nuts.
Lower the vehicle as instructed, tighten the lug nuts in the specified pattern to the correct torque, and check the spare’s pressure before driving. Obey the spare’s speed and distance limits and go to a repair facility promptly.
Do I Really Inflate My Spare Tire to 60 PSI?
Often, yes—if your compact temporary spare is specified for 60 PSI. AAA and several manufacturer instructions use 60 PSI for many donut spares, but you should verify the exact pressure for your vehicle instead of treating 60 PSI as universal.
A full-size spare may use a different pressure, and a collapsible spare may require a special inflation procedure. Follow the owner’s manual and vehicle tire-information label for the correct setup.
Conclusion
To inflate a spare tire safely, first confirm the correct cold PSI for your exact vehicle and spare type. Check the tire with a gauge, add air gradually, recheck the reading, and inspect the spare for damage, age, and repeated pressure loss.
Keep the spare on a monthly tire-pressure checklist and check it before long trips. If it is a temporary spare, treat it as a short-term emergency solution and follow the manufacturer’s speed, distance, and inflation limits until the regular tire is repaired or replaced.
