Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Summary
A flat tire is discovered at the worst possible moment, and that is exactly when most drivers learn their spare has a problem too. This check finds a bad spare while the car is still on the driveway: is the wheel actually there, is the tire free of damage, and does it hold the pressure it needs. It needs no lifting equipment and takes about fifteen minutes. Federal regulation requires the vehicle placard to carry a recommended cold inflation pressure for the spare tire, the same placard that carries the figure for the road tires.
Two things surprise most drivers. A temporary spare tire needs far more air than a road tire, and its own label and the vehicle placard both say so. Many newer vehicles carry no wheel at all: a tire sealant kit with its own expiry date takes its place, and that kit has its own page on this site. What this page will not print is a single pressure value or a single speed limit for every car — those are per-vehicle figures, printed on the placard and on the tire itself, and a page that guessed one would be guessing with the number that decides whether the tire holds.
Necessary equipment
| Item | Note |
|---|---|
| Tire pressure gauge | A dial gauge, a digital gauge or a pencil gauge is satisfactory. |
| Air supply | An air hose at a service station or a small compressor is satisfactory. |
| Flashlight optional | The light below the load floor is low. |
| Pen and paper | Write the pressure value and the maximum speed on the paper. |
| Vehicle documentation | The documentation gives the location of the spare tire and the limits. |
| Valve caps material | A valve cap prevents the entry of dirt. |
Stop the vehicle
Estimated under a minute
STOP THE VEHICLE AWAY FROM TRAFFIC BEFORE YOU START THIS CHECK.
Traffic can kill you.
- Stop the vehicle on a level surface away from traffic.<1mReport a problem with step 1, Stop the vehicle
- Set the parking brake.<1mReport a problem with step 2, Stop the vehicle
- Open the trunk or the cargo area.<1mReport a problem with step 3, Stop the vehicle
Find the spare tire
Estimated 2 min to 5 min
- Find the spare wheel under the load floor or below the vehicle.1mReport a problem with step 1, Find the spare tire
- The vehicle documentation gives the exact location.
- If you find a sealant kit instead of a wheel, stop this check.<1mReport a problem with step 2, Find the spare tire
- A tire sealant kit has a bottle of liquid and a small pump.
LIFT THE SPARE WHEEL WITH YOUR LEGS, NOT YOUR BACK.
A heavy wheel can cause back strain.
- Remove the spare wheel from its mount.1mReport a problem with step 3, Find the spare tire
- A hold-down bolt or a wing nut holds the spare wheel in place.
Examine the spare tire
Estimated 4 min to 6 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Compare the spare tire with a road tire.<1mReport a problem with step 1, Examine the spare tire
- A tire smaller than a road tire is a temporary spare tire.
- Examine the tread of the spare tire for wear.<1mReport a problem with step 2, Examine the spare tire
- Examine the sidewall of the spare tire for a crack.<1mReport a problem with step 3, Examine the spare tire
- Examine the sidewall of the spare tire for a bulge.<1mReport a problem with step 4, Examine the spare tire
- Examine the tread of the spare tire for a cut or an object.<1mReport a problem with step 5, Examine the spare tire
DO NOT USE A SPARE TIRE WITH A CRACK, A BULGE OR A CUT.
A damaged tire can fail and injure you.
- If you find a crack, a bulge or a cut, do not use the spare tire.<1mReport a problem with step 6, Examine the spare tire
- Find the DOT date code on the sidewall of the spare tire.<1mReport a problem with step 7, Examine the spare tire
- The date code gives the week and the year of manufacture.
- Find the maximum speed on the sidewall of the spare tire.<1mReport a problem with step 8, Examine the spare tire
- Some vehicles have no separate speed limit for a full-size spare tire.
- Write the maximum speed on the paper.<1mReport a problem with step 9, Examine the spare tire
Do a check of the spare tire pressure
Estimated 4 min to 8 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Find the vehicle placard on the pillar or on the edge of the driver door.<1mReport a problem with step 1, Do a check of the spare tire pressure
- The placard carries the title Tire and Loading Information.
- Read the recommended cold inflation pressure for the spare tire.<1mReport a problem with step 2, Do a check of the spare tire pressure
- A road tire needs less air than a temporary spare tire.
- Remove the valve cap from the spare tire.<1mReport a problem with step 3, Do a check of the spare tire pressure
- Push the gauge onto the valve until the sound of air stops.<1mReport a problem with step 4, Do a check of the spare tire pressure
- A gauge that is not square to the valve gives a low value.
- Read the value on the gauge.<1mReport a problem with step 5, Do a check of the spare tire pressure
- Compare the value on the gauge with the placard value for the spare tire.<1mReport a problem with step 6, Do a check of the spare tire pressure
SET THE SPARE TIRE TO THE VALUE ON THE VEHICLE PLACARD.
Do not use the maximum value from the tire sidewall. A tire at the wrong pressure can fail and injure you.
- If the value on the gauge is below the placard value, add more air in short periods.2mReport a problem with step 7, Do a check of the spare tire pressure
- Do a new measurement after each period.
- Stop the air supply when the gauge shows the placard value.<1mReport a problem with step 8, Do a check of the spare tire pressure
- Install the valve cap on the spare tire.<1mReport a problem with step 9, Do a check of the spare tire pressure
Record the result
Estimated 2 min
Source: Tire Safety Ratings and Awareness (TireWise) · tier 1 · accessed 2026-07-29
- Install the spare wheel in its mount.<1mReport a problem with step 1, Record the result
- Tighten the hold-down bolt or the wing nut.<1mReport a problem with step 2, Record the result
- Close the trunk or the cargo area.<1mReport a problem with step 3, Record the result
- Record the date of this check, the pressure value and the maximum speed.<1mReport a problem with step 4, Record the result
- Do this check before a long trip.<1mReport a problem with step 5, Record the result
- Do this check with the monthly check of the tire pressure.
Terminology
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
- spare tire
- Also called: spare wheel, donut, doughnut, space-saver spare, space saver, compact spare, does my car have a spare tire
- temporary spare tire
- Also called: mini spare, space-saver tire, T-type tire, stow-away spare, limited use spare, emergency tire
- vehicle placard
- Also called: Tire and Loading Information label, door jamb sticker, door sticker, tire placard, B-pillar sticker
- tire pressure gauge
- Also called: pressure gauge, air gauge, tyre gauge, pencil gauge, stick gauge
- DOT date code
- Also called: tire date code, born on date, how old is my spare tire, manufacture date, week and year code
- hold-down bolt
- Also called: wing nut, spare tire bolt, retaining bolt, spare tire wing nut
When to use a professional
Stop this check if you find a crack in the sidewall. Stop this check if you find a bulge in the sidewall. Stop this check if the tire will not hold air. Speak to a tire specialist.
If the vehicle has no spare wheel and no sealant kit, speak to a roadside assistance service.
A tire that loses air quickly needs a tire specialist, not more air. Some vehicle manufacturers give a maximum age for a tire, whatever the tread depth. Consult the vehicle manufacturer and the tire manufacturer for that age.
Common questions
Does my car even have a spare tire?
Not always, and it is worth confirming before you need it. Many vehicles carry a full-size spare or a smaller temporary spare under the load floor or below the rear of the vehicle. A growing number carry no wheel at all: a tire sealant kit with a bottle of sealant and a small compressor takes its place, and that kit has its own expiry date and its own page on this site. Your vehicle documentation states which one your car has and exactly where it is.
How much air should be in my spare tire?
Whatever the vehicle placard says, and federal regulation is what puts that figure there. 49 CFR 571.110 requires the placard to carry the vehicle manufacturer's recommended cold inflation pressure for the front, rear and spare tires, so the same label that sets your road tire pressure also sets your spare's. A temporary spare tire commonly needs a much higher pressure than a road tire, which is why this page tells you where to look rather than printing one number for every car.
What is the difference between a full-size spare and a 'donut'?
Size, weight and how long you are meant to use it. A full-size spare matches your road tires and can usually stay on the vehicle like any other tire. A temporary spare tire, often called a donut, a doughnut or a space-saver, is smaller and lighter, is meant only for a short period, and typically carries a speed limit printed on its own sidewall.
How fast can I drive on a spare tire?
Read the limit on your own tire, because it is not the same for every vehicle. As one example, Mazda's owner's manual for the current Mazda3 tells owners not to exceed 80 km/h (50 mph) on the temporary spare tire, and states that a temporary spare tire should never be used for long drives. Your own vehicle may set a different figure, so this page has you write yours down rather than borrow Mazda's.
How old is too old for a spare tire?
A spare can age out even though it is almost never driven on. NHTSA states that some vehicle and tire manufacturers recommend replacing tires that are six to ten years old, regardless of treadwear, and a spare sitting untouched in the trunk is not exempt from that clock. The DOT date code on the sidewall gives the week and year of manufacture, so you can work out its age the same way you would for a road tire.
How often should I check my spare?
NHTSA asks drivers to check the pressure of all tires, including the spare, at least once a month, and folding this check into that same monthly habit is the easiest way to remember it. It is also worth a quick look before a long trip, since that is when a bad spare costs the most.
My car has no physical spare wheel — what do I do?
Look for a tire sealant kit instead: a small case, usually in the trunk, holding a bottle of sealant and a compressor. It has its own inspection routine, built around the sealant's expiry date rather than a tire's condition and pressure, and this site covers that check on its own page.
Related procedures
- How to read a tire sidewall and find out how old your tires are
- How to check your tire pressure and put the right amount of air in your tires
- What the tire pressure light on my dashboard means and what to do about it
- How to read the tire and loading information placard and work out how much load you have left for passengers and cargo
- How to check the tire sealant and inflator kit your car carries instead of a spare tire
- Read the treadwear, traction and temperature grades moulded on a tire and know what they do and do not compare
- How to check tire tread depth and know when you need new tires
- How do I check that my lug nuts (wheel nuts) are still tight after a tire shop, a mobile fitter, or a roadside wheel change?
Sources
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
- Tier 1Tire Safety Ratings and Awareness (TireWise)
- Tier 149 CFR 571.110 — FMVSS No. 110, Tire selection and rims
- Tier 1Spare Tire - 2026 Mazda3 Owner's Manual
Revision history
Current version 1 · updated 2026-08-04 · next review due 2027-08-04
- v1 · 2026-08-04First draft. The spare tire's own pressure and speed limit publish as consult-the-vehicle-placard and consult-the-tire-sidewall instructions, per rule 1, because both are per-vehicle values: 49 CFR 571.110 S4.3(c) establishes that the placard covers the spare tire figure specifically, and no single number is safe to print for every car. The monthly interval rests on NHTSA TireWise, quoted there as covering all tires 'including your spare'. The 50 mph temporary-spare speed limit and the associated handling warnings are Mazda's own current Mazda3 owner's manual, quoted directly, and are presented in the FAQ as one manufacturer's example rather than as the page's verified value. The replacement-age note reuses NHTSA's six-to-ten-year statement, also unverified as a universal number and routed to the vehicle and tire manufacturers. This record does not duplicate check-tire-pressure's monthly all-tire walkthrough or check-a-tire-sealant-kit's sealant inspection: it is scoped to the presence, physical condition and pressure of a spare wheel specifically, and step s5 hands a reader with a sealant kit instead of a wheel to that sibling page rather than re-deriving its content.
Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.
Comments and corrections
Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.
Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.