Spare tire types explained
What are the different types of spare tire?
Emergency equipment may include a full-size or temporary spare, run-flat tires or a mobility kit. Check the exact vehicle handbook and product instructions for use, axle placement, speed and distance limits; the equipment alone does not guarantee continued driving.
Spare tire types: full comparison
| Type | Speed limit | Distance limit | Weight | Cost | Best for |
|---|---|---|---|---|---|
| Full-size matching spare | None — same rating as fitted tires | None | 15–25 kg (typical passenger car) | £100–£400 depending on tire and rim | Long-distance drivers, remote areas, AWD vehicles, any driver who cannot service a tire quickly |
| Space-saver (temporary use) | Maximum 80 km/h (50 mph). Posted clearly on sidewall. | 80 km (50 miles) recommended — some manufacturers allow up to 200 km at reduced speed | 7–12 kg | £60–£180 | Urban and suburban drivers who can reach a tire fitter quickly |
| Run-flat tires (no spare) | Follow the exact tire and vehicle speed limits. | Follow the product limits; no universal remaining range. | Check the exact product weight. | Compare current quotes for the exact product. | Use only under the tire and vehicle maker’s fitment instructions. |
| Tire mobility kit (sealant + compressor) | Maximum 80 km/h after sealing, for limited distance to reach a fitter | 100–200 km after sealing to reach a tire fitter (varies by product) | 1–3 kg | £25–£80 for kit; canister must be replaced after use (£15–£40) | EVs and vehicles where space and weight are critical (e.g. two-seater sports cars) |
| Full-size non-matching spare | Matches its own speed rating — no inherent speed restriction beyond the tire itself | No specific limit — but should not be used long-term as a permanent replacement on AWD | 15–25 kg | Variable — often a surplus tire from previous season | Budget-conscious drivers; acceptable for FWD/RWD vehicles; avoid on AWD |
Space-saver spare: rules and restrictions
| Rule | Detail | Consequence of ignoring |
|---|---|---|
| Speed limit | Maximum 80 km/h (50 mph). This is marked on the tire sidewall. The narrower tire generates less heat at the contact patch but lacks the lateral stiffness and load rating of the standard tire at higher speeds. | Exceeding 80 km/h on a space-saver risks tire failure, unpredictable handling, and reduced braking. |
| Distance limit | Manufacturers typically state 50–80 km as the operational range. Beyond this, heat accumulation in the lighter carcass and reduced compound volume can lead to accelerated wear and structural fatigue. | Use the space-saver only to travel to the nearest tire fitter, not as a continuing solution. |
| Axle placement | Space-saver tires must not be fitted on the steering axle (front) of vehicles with stability-critical systems calibrated to the standard tire circumference — ABS, ESC, and TPMS may behave unexpectedly. Some manufacturers prohibit front fitment. | Check your owner’s manual. If the space-saver specifies "rear axle only," fit it at the rear and move a damaged front tire to the rear position (if the rear tire is undamaged). |
| AWD (All-wheel drive) vehicles | AWD systems with permanent torque distribution (Haldex, Torsen, etc.) are sensitive to different tire rolling circumferences on the same axle or across axles. A space-saver’s smaller circumference can cause the AWD system to register a permanent "slip" condition, potentially damaging the centre differential or clutch pack. | Manufacturers of AWD vehicles typically prohibit space-saver use. Use a full-size spare only. |
| TPMS | Space-saver tires typically do not include a TPMS sensor, or the sensor frequency may differ. Fitting a space-saver will trigger the TPMS warning light. This is expected — the light should be off once the standard tire is refitted and the system re-learns. | The TPMS warning during space-saver use is not a fault — it is expected. Drive carefully. |
Identify the exact tire
Bridgestone identifies its run-flat tyres with RFT on the sidewall and requires a functioning TPMS. Codes differ by manufacturer; a reinforced or XL marking alone does not identify run-flat capability. Check the full product specification and the vehicle handbook.
Source: Bridgestone — Run-flat: identification, TPMS, speed/distance, application
Low-pressure operating limits
As a manufacturer-specific example, Bridgestone describes a low-pressure speed limit of 50 mph (80 km/h). The sidewall distance limit controls; if none is marked, consult the vehicle manual. The FAQ says not to exceed 50 miles (80 km) when in doubt. Test maximums can differ in real use and are not guaranteed remaining range.
Source: Bridgestone — Run-flat: identification, TPMS, speed/distance, application
Can it be repaired?
Bridgestone allows some puncture repairs subject to restrictions and inspection. Pressure loss, speed, load, manoeuvres, temperature and damage location affect the decision. The tyre must be removed for internal inspection; some vehicle makers advise against repaired tyres. No blanket claim that every repair voids every warranty is made here.
Source: Bridgestone — Run-flat: repair restrictions and inspection
Replacing the tire
Before replacing run-flats with conventional tyres, obtain the vehicle and tyre maker’s fitment instructions and an appropriate puncture plan. Bridgestone advises against mixing or replacement except for temporary emergency use meeting vehicle requirements. Do not apply one brand’s allowance to another product.
Source: Bridgestone — Run-flat: identification, TPMS, speed/distance, application
Information for the workshop
Record the warning time, pressure readings and distance travelled after the alert for the technician. This is a sourced product-use example, not approval to continue with a damaged tyre. The guide does not promise a fixed price premium, wear penalty or repair outcome.
Tire mobility kit: when it works and when it does not
| Scenario | Detail | Notes |
|---|---|---|
| Works | Clean puncture (nail, screw, wire) through the tread area. Puncture diameter approximately 1–4 mm. | The sealant fills the hole temporarily. The tire must be driven gently immediately after sealing to distribute the compound around the puncture. |
| Does NOT work | Sidewall damage, large tread tears, bead damage, or punctures larger than ~4–6 mm. | Sealant cannot seal a sidewall puncture. If the tire is damaged on the sidewall, the mobility kit is useless — you need roadside assistance or a spare tire. |
| Notes | Pressure loss or damage after low-pressure driving: do not assume a mobility kit or run-flat capability permits continued use. | Arrange internal and external inspection; repairability depends on the tire, damage and vehicle instructions. |
| Tire unusable after sealant | After sealant use, the tire interior is coated. Patches cannot adhere to sealant-coated surfaces — standard puncture repair is no longer possible. | Inform the tire fitter that sealant was used. They will assess whether cleaning and repair is possible or whether replacement is required. In most cases, the tire is replaced. |
| TPMS sensor compatibility | Sealant can clog TPMS sensors. Some sealants are TPMS-compatible (labelled accordingly). Non-compatible sealants may require sensor replacement on top of tire replacement. | Check whether your kit is TPMS-compatible before an emergency. Tesla, for example, requires a TPMS-compatible sealant. |
OEM spare tire policy by manufacturer
| OEM | Standard spare policy | Mobility kit | Full-size spare available? |
|---|---|---|---|
| BMW / MINI (i-Series) | Check the exact vehicle model, fitted tires and emergency equipment in its handbook. | Check the exact vehicle model, fitted tires and emergency equipment in its handbook. | Check the exact vehicle model, fitted tires and emergency equipment in its handbook. |
| Tesla | No spare tire. Self-sealing tires standard on Model 3/Y (Michelin PrimacyMXM4 Acoustic with sealant layer). | Tesla Emergency Inflation Kit included — TPMS-compatible sealant + compressor | No official spare tire. Aftermarket full-size spare available from third parties. |
| Volkswagen / Audi / Porsche (MQB platform) | Mix of space-saver and mobility kit depending on model and market. Taycan uses space-saver or RFT. | Standard on many Golf/Polo variants — Audi mobility kit or VW Tire Mobility Kit | Full-size matching spare available as option on most VW Group models |
| Toyota / Lexus | Full-size or space-saver spare standard on most ICE models. Hybrids (Prius, RAV4 Hybrid) often use mobility kit. | Toyota Tire Puncture Repair Kit — included on many hybrid models | Full-size spare available on most ICE models |
| Stellantis (Citroën / Peugeot / Fiat / Vauxhall) | Trend toward mobility kits on B-segment and C-segment. C5 Aircross / 5008 offer space-saver option. | Emergency puncture repair kit (Slime or equivalent) on many models | Space-saver spare widely available as dealer option |
The trend away from spare tires
Since approximately 2010, the automotive industry has shifted strongly toward eliminating the physical spare tire to save weight, reduce CO₂ emissions (lighter car = lower fuel consumption = lower regulatory penalty), and free up boot space. The proportion of new cars sold without a full-size spare tire increased from approximately 5% in 2005 to over 35% in 2023 in the EU.
Check the exact vehicle model, fitted tires and emergency equipment in its handbook.
The practical consequence: when buying a used vehicle, check whether it includes a working spare tire or mobility kit — second-hand cars often arrive missing the kit or with an expired canister.
How to maintain a spare tire in good condition
| Check | Frequency | What to look for |
|---|---|---|
| Tread depth | Annually | Spare tires rarely used but age and crack regardless. Check tread depth with a gauge — minimum 3 mm for safe use, 1.6 mm is the legal minimum. A full-size spare below 1.6 mm is unusable in an emergency. |
| Cold inflation pressure | Monthly (or at least every 3 months) | Spares lose pressure through permeation even when stored unused. A space-saver spare typically requires 420 kPa (60 PSI) — much higher than a standard tire. Full-size spares lose ~0.07 bar per month through normal permeation. |
| Sidewall cracking | Annually | Ozone cracking occurs even in stored tires. A spare with Grade 3–4 sidewall cracking (cracks reaching the cord layer) is dangerous regardless of its low mileage. Age (DOT date code) is as important as tread — see our tire age guide. |
| DOT age | At purchase of vehicle and annually thereafter | A full-size or space-saver spare tire older than 10 years (from the DOT manufacture date, even if barely used) should be replaced. Most manufacturers recommend replacement at 6–8 years for the spare, same as fitted tires. |
| Mobility kit expiry | Annually | Sealant canisters have an expiry date (typically 4–10 years from manufacture). An expired canister may not seal effectively. Check the canister date printed on the label. |
For tire age assessment, see our tire age guide and our tire cracking and ageing guide.
Legal requirements for spare tires
No EU member state or the UK legally requires a spare tire to be carried in a private passenger vehicle. However, some countries require vehicles to carry certain emergency equipment — reflective triangles, vests, first aid kits — which vary by country. Notably:
- UK : No legal requirement for a spare tire in a private car. A roadside call-out for a flat tire is the driver’s responsibility.
- Germany : No legal requirement for a spare tire. Reflective triangle and warning vest are legally required.
- France : No legal requirement for a spare tire. Reflective triangle required.
- Spain : No legal requirement for a spare tire. Two reflective triangles and a warning vest required.
While not legally mandated, TPMS (Tire Pressure Monitoring System) is mandatory on all new cars sold in the EU and UK since 2014, which means any tire pressure loss will be detected before it becomes a full flat. For the full TPMS guide, see our TPMS guide.
Sources checked for the cited claims: 2026-09-30
Seasonal check
Winter tire rules coming up?
Check tread depth, markings and local winter requirements before the first cold spell instead of waiting for the appointment rush.