Spare tire, jack and wheel tools: know your spare and change a flat safely
Find your tools, lift the car safely and know the limits of a compact spare
Safety Behind the Wheel Foundation built this guide from National Highway Traffic Safety Administration (NHTSA) tire guidance, federal vehicle and workplace safety rules, the Federal Highway Administration (FHWA), the AAA Foundation for Traffic Safety and the UK Highway Code. It focuses on the spare, the jack and the wheel tools. Every source is listed at the end. Our vehicle maintenance guide covers pressure, tread and age checks for every tire, spare included.
Why your spare and tools deserve 15 minutes now
The best time to learn your spare and tools is a dry afternoon in your own driveway, not a dark roadside.
After you stop, the two big dangers are passing traffic and a lifted car. A AAA Foundation for Traffic Safety study counted 123 roadside assistance workers, such as tow operators, struck and killed while working from 2015 through 2021 [2]. Nearly 9 in 10 of those deaths happened where the speed limit was 55 mph or higher [2]. If trained crews with warning lights face that risk, so does a driver kneeling by a wheel.
For where to stop and how to stay visible, see our roadside breakdown safety guide. For keeping control when a tire fails at speed, see our guide to blowouts and other driving emergencies.
Know which spare your car carries
Look under your trunk or cargo floor this week. Many cars keep the spare there. Many pickups hang it under the rear on a cable that you lower with a rod from the tool kit. Some vehicles have no spare at all. The federal tire pressure monitoring standard, for example, refers to the spare only “if provided” [3].
Your best guide is the tire information placard, usually on the driver’s door pillar. Federal rules require it to list tire sizes and the maker’s recommended cold air pressures, including the spare in most cases [4]. “Cold” means the car has not been driven for a while.
Comparison compiled by Safety Behind the Wheel Foundation
Types of spare tires and their limits
| Spare type | What it is | Key limits |
|---|---|---|
| Full size matching | Same tire and wheel as the other four | Fine for a flat. NHTSA says not to use it to replace worn tires except in emergencies [1] |
| Full size nonmatching | Same size tire, often on a plain steel wheel | Check its tread and age |
| Compact temporary (“donut”) | Smaller, narrower, lighter tire | Lower speed and distance limits. Often needs much higher pressure |
| Airless temporary (rare) | A spare assembly with no air in it | Federal label must say temporary use only, 50 mph maximum [4] |
| No spare | Sealant kit or run flat tires | Kits cannot fix torn or sidewall damaged tires. Run flats go only a limited distance |
A compact spare often needs far more air than your regular tires. One sample placard in an NHTSA tire buyer guide lists 60 psi for a compact spare [5]. Read your own placard rather than guessing. If your car has a sealant kit instead, our companion guide on emergency tire repair kits covers it.
The tools in the kit and what each one does
The tool kit may sit under the floor, behind a panel or under a seat.
- Jack. Most factory jacks are scissor jacks, a folding diamond shaped frame that rises as you turn a screw. Pickups often come with a bottle jack, a short round post.
- Jack handle or crank. It turns the jack screw and may also lower an under vehicle spare.
- Lug wrench. It removes the lug nuts that hold the wheel on. Factory wrenches are short, so tight nuts take effort.
- Wheel lock key. Some wheels have one locking nut with a special pattern. Without its key, that wheel stays on.
- Owner’s manual. It shows your car’s lift points and steps.
Useful additions include a cross shaped lug wrench for leverage, wheel chocks (wedges that stop a tire from rolling), a sturdy board for soft ground, gloves and a tire gauge.
Garage jacks and jack stands
A floor jack lifts more steadily than a factory jack, but it is heavy and made for hard, level floors. Jack stands are fixed supports that hold a car up after it is lifted. They belong at home, any time part of your body will go under the car. OSHA’s workplace rule requires a jack’s rated load to be marked clearly and permanently on it, so look for that rating [6].
Where to get the right gear
- The dealer’s parts department can supply a factory jack, a matching spare and wheel, or a new lock key.
- Tire shops can sell, mount and balance a spare.
- Auto parts stores carry wrenches, chocks, gauges and jack stands.
- Outdoor retailers and safety suppliers carry gloves, boards, lights and heavier gear.
If you add a spare, match the size on your placard [4] and make sure the wheel fits over your brakes. Check its age, too. The last four digits of the DOT tire identification number show the week and year it was made [5].
Change it yourself or call for help?
Changing a wheel is not hard. The setting is what makes it safe or dangerous.
The United Kingdom’s Highway Code offers a useful benchmark. It tells drivers stopped on a motorway or other high speed road not to attempt repairs [7]. It says to wait well away from the vehicle and traffic, behind a barrier if there is one [7]. Safety Behind the Wheel Foundation gives drivers the same advice.
Comparison compiled by Safety Behind the Wheel Foundation
Change it yourself or call for help
| Your situation | Safer choice |
|---|---|
| Quiet street, parking lot or driveway on level pavement | Change it yourself if you are able |
| Highway or busy road shoulder | Call for help and wait in a safe spot |
| Flat is on the side facing traffic | Roll slowly to a safer spot, or call |
| Soft ground, gravel, a slope or a curve | Move to level, hard ground, or call |
| Darkness, fog or heavy rain near traffic | Call for help |
| Stuck nuts, missing lock key or flat spare | Call for help |
| Bent wheel after a curb or pothole hit | Call. A tow may be safer |
| Injury, physical limits or young children to watch | Call for help |
Many busy highway systems run service patrols that drive set routes to help stranded drivers. A Federal Highway Administration handbook lists changing flat tires among their services and describes them as free motorist assistance [8]. Roadside plans from insurers, auto clubs and automakers also help, so save those numbers.
Before you lift: set up a stable work spot
A jack is only as steady as the ground under it.
Step by step: changing the tire
Follow your owner’s manual first, since lift points differ by model. This routine fits most passenger cars.
- Remove the wheel cover, if there is one.
- With the tire still on the ground, loosen each lug nut about half a turn counterclockwise. Use the lock key on the locking nut.
- Find the lift point nearest the flat. It is often a marked notch along the edge under the doors.
- Set the jack there on solid ground or your board. Raise it until it touches, then check that it stands straight.
- Raise the car until the flat is about an inch off the ground.
- Remove the nuts, keep them together and pull the wheel straight off.
- Slide the flat under the side of the car near the jack. It may limit a drop if the jack slips.
- Lift the spare on and thread each nut by hand so it does not cross thread.
- Snug the nuts in a star or crisscross pattern so the wheel seats evenly.
- Lower the car until the spare carries some weight, then tighten the nuts firmly in the same pattern.
- Lower the car fully, remove the jack and store everything securely so nothing flies forward in a hard stop.
Common mistakes to avoid
- Loosening the nuts after the car is up, which spins the wheel and rocks the jack.
- Jacking on soft ground, gravel or a slope.
- Finding out at the roadside that the spare is flat or the lock key is missing.
- Tightening the nuts in a circle instead of a star pattern.
- Driving on a compact spare for weeks instead of days.
A jack lifts. It does not hold.
A jack alone is not under vehicle support. A factory jack has a small base and presses on one point of the body. A soft shoulder, wind from a passing truck or a bump against the car can tip it.
Crush asphyxia means a person cannot breathe because heavy weight presses on the chest. Forensic researchers note that when it involves motor vehicles, it usually happens under a vehicle that slipped off a jack or a car that rolled over in a collision [9].
Workplace rules agree. OSHA says a raised load must be cribbed (supported by stacked blocks), blocked or otherwise secured right away [6]. The rule also says a jack’s base must be blocked when the ground is not firm [6].
- Never put any part of your body under the car while it sits on a jack.
- Never start the engine or let anyone sit inside while it is raised.
- Lift only at the points in your manual. Other spots can bend metal and let the jack slip.
- If the jack leans or the car shifts, lower it and reset.
- For under car work at home, use rated jack stands on a hard, level floor with the wheels chocked. Never trust bricks or cinder blocks.
OSHA also requires workplace jacks to be lubricated regularly and taken out of use when they are out of order [6]. At home, replace a bent, sticking or leaking jack.
Driving on the spare and getting back to normal
Check the spare’s pressure at your first safe stop, then head for a tire shop. A compact spare has less grip than a regular tire. Stay under the speed and distance limits on its sidewall or in your manual. For the rare airless spare, the federal label sets 50 mph [4]. Leave extra following distance, since braking and cornering may feel different.
Your tire pressure warning light may come on with the spare. Federal rules require owner’s manuals to tell drivers to check the system’s malfunction light after replacing tires or wheels [3]. The low pressure warning only has to come on once a tire is about 25% low, so a gauge is still the better check [3].
Then take care of the flat:
- Have a tire shop check whether it can be repaired or must be replaced.
- Have the lug nuts tightened to the maker’s specification with a torque wrench.
- Return the spare to storage at the correct pressure.
Who needs what: families, fleets and remote travelers
Families. Practice one tire change in the driveway, and make it part of a new teen driver’s first year skills. Agree that a flat beside fast traffic means a call for help.
Fleets. A fleet policy can say who may change tires and where, and when drivers must call a service instead. Add the spare, jack, wrench and lock key to vehicle inspections. Heavy vehicles are a different job. OSHA’s rim wheel standard covers servicing wheels on trucks, trailers and buses and requires training and restraining devices [10]. It does not cover cars, or pickups and vans with car or LT tires [10]. Our guide to journey management for work drivers covers breakdown plans.
Remote travelers. Far from service, a full size spare is worth more than a compact one. Check its pressure and age before you leave, and tell someone your route. NHTSA’s winter guidance advises staying with your car if you are stranded and not overexerting yourself [11]. It also suggests carrying a flashlight, warning devices, a first aid kit, blankets, water, food and a phone charger [11].
Keep the kit ready: a simple upkeep routine
A spare that sits for years loses air and ages. A jack that never moves can rust or stick.
If a factory jack, wheel or tire fails in a way that seems like a defect, you can report it to NHTSA [12].
Frequently asked questions
How fast and how far can I drive on a compact spare?
Follow the limits printed on the spare’s sidewall or in your owner’s manual. For the rare airless temporary spare, the federal label limits speed to 50 mph [4]. Treat any compact spare as a way to reach a tire shop, not a tire to keep using.
Can I use my car’s jack to work under the car?
No. The factory jack is made only for lifting a corner to change a wheel. Forensic researchers note that vehicle related crush asphyxia usually involves a car slipping off a jack or a rollover [9]. For work under the car, use a hard, level floor, rated jack stands and wheel chocks.
Should I change a flat on the highway shoulder?
It is safer not to. Most roadside assistance workers killed from 2015 through 2021 were struck where limits were 55 mph or higher [2]. If you can roll slowly to an exit or parking lot, do that. If not, wait in a safe place away from the car and call for help.
My car has no spare tire. Should I add one?
It depends on where you drive. A sealant kit cannot fix torn or sidewall damaged tires, so a spare may be worth the space if you travel far from cities. Match the size on your door placard [4] and confirm the wheel fits over your brakes. You will also need a jack, a lug wrench and a secure place to store it.
Why is my tire pressure light on after I put on the spare?
Your spare may not have a pressure sensor. The federal standard requires warnings for up to four tires, so the spare is not part of the required system [3]. Check the spare with a gauge. If the light stays on after your repaired tire is back on, have the system checked.
What if I cannot get the lug nuts loose?
Turn counterclockwise with the tire still on the ground. Use a longer or cross shaped wrench and push with steady force. Do not jump on a short factory wrench, since it can slip and cause a fall. If the nuts still will not move, stop and call for help.
The bottom line
Recommendation from Safety Behind the Wheel Foundation
Safety Behind the Wheel Foundation urges drivers to learn their spare and tools at home and to call for help rather than change a tire beside fast traffic. A spare and jack only help if you know what you have and when to use them. Learn your spare, find every tool, practice once and keep the spare’s pressure and age in check.
When a flat happens, let the location decide. On level ground away from traffic, a careful change is a skill worth having. Beside fast traffic, your phone is the safest tool you own. And never trust a jack to hold a car while any part of you is under it.
Related articles
- Roadside breakdown safety: what to do when your car breaks down
- Car emergencies while driving: blowouts, brake failure and skids
- Vehicle maintenance for safety: tires, brakes, lights and warning signs
- Journey management for work drivers: weather, breakdowns and check ins
- Rural road safety: why country roads are deadlier and how to drive them
Sources and further reading
- 1National Highway Traffic Safety Administration. Tire Safety Ratings and Awareness | TireWise. No date shown; accessed October 2026. Data year: 2024 (tire-related deaths); guidance otherwise. nhtsa.gov/vehicle-safety/tires
- 2AAA Foundation for Traffic Safety. Roadside Assistance Providers Fatally Struck by Vehicles at the Roadside: Incidence and Characteristics. Published January 2024. Data year: 2015 to 2021. aaafoundation.org/…/roadside-assistance-providers-fatally-…
- 3Electronic Code of Federal Regulations. 49 CFR 571.138, Standard No. 138; Tire pressure monitoring systems. Up to date as of October 1, 2026. ecfr.gov/…/section-571.138
- 4Electronic Code of Federal Regulations. 49 CFR 571.110, Standard No. 110; Tire selection and rims information (vehicles with a GVWR of 10,000 pounds or less). Up to date as of October 2, 2026. ecfr.gov/…/section-571.110
- 5National Highway Traffic Safety Administration. Tire Buyers’ FAQ: What You Should Know and Ask. No date shown (document code 070815); accessed October 2026. nhtsa.gov/node/35301
- 6Electronic Code of Federal Regulations. 29 CFR 1910.244, Other portable tools and equipment (jacks). Up to date as of October 1, 2026. ecfr.gov/…/section-1910.244
- 7UK Government (Department for Transport). The Highway Code: Breakdowns and incidents (274 to 287). Updated October 22, 2025. gov.uk/…/breakdowns-and-incidents-274-to-287
- 8Federal Highway Administration. Service Patrol Handbook (FHWA-HOP-08-031). Published November 2008. ops.fhwa.dot.gov/…/ffsp_handbook.pdf
- 9Byard RW, Woodford NWF. Automobile door entrapment: a different form of vehicle-related crush asphyxia. Journal of Forensic and Legal Medicine 15(5):339-342; PubMed publication date November 2007. pubmed.ncbi.nlm.nih.gov/18511012
- 10Electronic Code of Federal Regulations. 29 CFR 1910.177, Servicing multi-piece and single piece rim wheels. Up to date as of October 1, 2026. ecfr.gov/…/section-1910.177
- 11National Highway Traffic Safety Administration. Winter Weather Driving Tips: Prepare Your Vehicle. No date shown; accessed October 2026. nhtsa.gov/winter-driving-tips
- 12National Highway Traffic Safety Administration. Report a Vehicle Safety Problem, Equipment Issue. No date shown; accessed October 2026. nhtsa.gov/report-a-safety-problem
This article reflects the safety priorities of tire care and roadside safety for everyday drivers. It is general safety education, not legal, insurance or professional repair advice, and it does not replace your owner's manual. Rules change, so verify details with official sources. For your own vehicle, ask a qualified tire shop or the dealer's service department. In an emergency beside traffic, call 911 or your roadside assistance provider. Reviewed October 2026.
Cite this article: Safety Behind the Wheel Foundation. “Spare tire, jack and wheel tools: know your spare and change a flat safely.” drivewithcare.org, https://drivewithcare.org/spare-tire-jack-wheel-tools/. Reviewed October 2026.
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