Spare tyre types explained
What are the different types of spare tyre?
There are five main spare tyre configurations: (1) Full-size matching spare — identical to the fitted tyres, no speed or distance restriction, but heavy and expensive. (2) Space-saver (temporary use) spare — narrower than standard, typically limited to 80 km/h and 80 km; must not be fitted on the drive axle of vehicles with traction control calibrated to the standard tyre width. (3) Run-flat tyres — allow driving at up to 80 km/h for up to 80 km after complete pressure loss; no spare carried. (4) Tyre mobility kit (sealant + compressor) — seals punctures up to about 4 mm in the tread only; does not work on sidewall damage; the tyre must be replaced after sealant use. (5) Full-size non-matching spare — correct diameter but different brand or pattern; avoid on drive axle of AWD vehicles.
- There are five main spare tyre configurations: (1) Full-size matching spare — identical to the fitted tyres, no speed or distance restriction, but heavy and expensive.
- (2) Space-saver (temporary use) spare — narrower than standard, typically limited to 80 km/h and 80 km; must not be fitted on the drive axle of vehicles with traction control calibrated to the standard tyre width.
- (3) Run-flat tyres — allow driving at up to 80 km/h for up to 80 km after complete pressure loss; no spare carried.
FAQ
- What are the different types of spare tyre?
- There are five main spare tyre configurations: (1) Full-size matching spare — identical to the fitted tyres, no speed or distance restriction, but heavy and expensive. (2) Space-saver (temporary use) spare — narrower than standard, typically limited to 80 km/h and 80 km; must not be fitted on the drive axle of vehicles with traction control calibrated to the standard tyre width. (3) Run-flat tyres — allow driving at up to 80 km/h for up to 80 km after complete pressure loss; no spare carried. (4) Tyre mobility kit (sealant + compressor) — seals punctures up to about 4 mm in the tread only; does not work on sidewall damage; the tyre must be replaced after sealant use. (5) Full-size non-matching spare — correct diameter but different brand or pattern; avoid on drive axle of AWD vehicles.
- What should I verify before using this information?
- Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.
Spare tyre types: full comparison
| Type | Speed limit | Distance limit | Weight | Cost | Best for |
|---|---|---|---|---|---|
| Full-size matching spare | None — same rating as fitted tyres | None | 15–25 kg (typical passenger car) | £100–£400 depending on tyre and rim | Long-distance drivers, remote areas, AWD vehicles, any driver who cannot service a tyre 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 tyre fitter quickly |
| Run-flat tyres (no spare) | 80 km/h maximum in run-flat mode (zero pressure) | 80 km maximum in run-flat mode. Varies by manufacturer. | 3–6 kg heavier than standard equivalent | 30–50% more than standard equivalent per tyre | Vehicles with no spare tyre well, sports cars, urban drivers; not for long-distance solo rural driving |
| Tyre 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 tyre 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 tyre itself | No specific limit — but should not be used long-term as a permanent replacement on AWD | 15–25 kg | Variable — often a surplus tyre 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 tyre sidewall. The narrower tyre generates less heat at the contact patch but lacks the lateral stiffness and load rating of the standard tyre at higher speeds. | Exceeding 80 km/h on a space-saver risks tyre 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 tyre fitter, not as a continuing solution. |
| Axle placement | Space-saver tyres must not be fitted on the steering axle (front) of vehicles with stability-critical systems calibrated to the standard tyre 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 tyre to the rear position (if the rear tyre is undamaged). |
| AWD (All-wheel drive) vehicles | AWD systems with permanent torque distribution (Haldex, Torsen, etc.) are sensitive to different tyre 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 tyres 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 tyre is refitted and the system re-learns. | The TPMS warning during space-saver use is not a fault — it is expected. Drive carefully. |
Run-flat tyres: what "80 km at 80 km/h" means
Run-flat tyres (also sold as RFT, SSR, RSC, ROF, EMT, or ZP depending on manufacturer) use reinforced sidewalls — typically self-supporting sidewalls with 15–20 mm of extra rubber and additional apex filler — to support the vehicle's weight when the air pressure drops to zero.
The "80/80 rule" (80 km/h for 80 km) is not a guarantee — it is the minimum the tyre must achieve under controlled test conditions. In practice:
- Heavy vehicles (above the tyre's rated load) shorten the run-flat range significantly.
- High ambient temperature reduces run-flat range — heat accelerates sidewall breakdown.
- Sustained speeds above 80 km/h in run-flat mode rapidly degrade the sidewall and can cause complete structural failure.
- After any run-flat use (even a short distance), the tyre must be inspected and in most cases replaced — internal carcass damage from sidewall flex cannot be seen externally.
Do not mix run-flat and conventional tyres. Run-flat and conventional tyres must not be mixed on the same axle (and many manufacturers prohibit mixing on the same vehicle). The handling asymmetry between a run-flat sidewall and a standard sidewall in the same cornering situation is significant. For the full run-flat guide, see our Run-flat tyre guide.
Tyre 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 tyre 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 tyre is damaged on the sidewall, the mobility kit is useless — you need roadside assistance or a spare tyre. |
| Does NOT work | Run-flat mode blowout (tyre driven on without pressure for any significant distance). | Internal carcass damage from run-flat operation cannot be repaired. Replace the tyre. |
| Tyre unusable after sealant | After sealant use, the tyre interior is coated. Patches cannot adhere to sealant-coated surfaces — standard puncture repair is no longer possible. | Inform the tyre fitter that sealant was used. They will assess whether cleaning and repair is possible or whether replacement is required. In most cases, the tyre 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 tyre replacement. | Check whether your kit is TPMS-compatible before an emergency. Tesla, for example, requires a TPMS-compatible sealant. |
OEM spare tyre policy by manufacturer
| OEM | Standard spare policy | Mobility kit | Full-size spare available? |
|---|---|---|---|
| BMW / MINI (i-Series) | Run-flat tyres standard on most BMW/MINI models. No spare tyre well. Run-flat mode: 80 km/h for 80 km. | Run-flat inflation kit available as supplement, not replacement for RFT | Full-size spare available as dealer option on some models. Check individual model spec. |
| Tesla | No spare tyre. Self-sealing tyres standard on Model 3/Y (Michelin PrimacyMXM4 Acoustic with sealant layer). | Tesla Emergency Inflation Kit included — TPMS-compatible sealant + compressor | No official spare tyre. 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 Tyre 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 tyres
Since approximately 2010, the automotive industry has shifted strongly toward eliminating the physical spare tyre 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 tyre increased from approximately 5% in 2005 to over 35% in 2023 in the EU.
For EVs this trend is even more pronounced: the battery pack occupies space previously used for a spare tyre well, and weight reduction is critical for range. Virtually all BEVs with a range above 300 km use either run-flat tyres, a tyre mobility kit, or self-sealing tyres in place of a physical spare.
The practical consequence: when buying a used vehicle, check whether it includes a working spare tyre or mobility kit — second-hand cars often arrive missing the kit or with an expired canister.
How to maintain a spare tyre in good condition
| Check | Frequency | What to look for |
|---|---|---|
| Tread depth | Annually | Spare tyres 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 tyre. Full-size spares lose ~0.07 bar per month through normal permeation. |
| Sidewall cracking | Annually | Ozone cracking occurs even in stored tyres. 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 tyre age guide. |
| DOT age | At purchase of vehicle and annually thereafter | A full-size or space-saver spare tyre 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 tyres. |
| 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 tyre age assessment, see our Tire age guide and Tyre cracking and ageing guide.
Legal requirements for spare tyres
No EU member state or the UK legally requires a spare tyre 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 tyre in a private car. A roadside call-out for a flat tyre is the driver's responsibility.
- Germany: No legal requirement for a spare tyre. Reflective triangle and warning vest are legally required.
- France: No legal requirement for a spare tyre. Reflective triangle required.
- Spain: No legal requirement for a spare tyre. Two reflective triangles and a warning vest required.
While not legally mandated, TPMS (Tyre Pressure Monitoring System) is mandatory on all new cars sold in the EU and UK since 2014, which means any tyre pressure loss will be detected before it becomes a full flat. For the full TPMS guide, see our TPMS guide.
More tools
- Run-flat tyre guide
- TPMS guide
- Tyre puncture repair guide
- MOT and roadworthiness tyre requirements
- Tire age guide
- Tyre cracking and ageing guide
- Tire & wheel reference guides
Seasonal check
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