The Regulatory Driver
Since the introduction of EU CO₂ emission standards (now retained in UK law), manufacturers have pursued weight reduction strategies. A spare wheel and jack assembly weighs 15–25kg. Removing it improves official fuel economy by approximately 0.2mpg on the NEDC test cycle and reduces the manufacturer’s fleet average CO₂ output.
This is not a conspiracy. It is compliance.
The Result: Repair Kits as Standard
By 2014, the RAC reported that call-outs to vehicles without spare wheels had doubled from 80,000 (2013) to 160,000 (2014), projecting 250,000 for 2015. The primary cause was drivers unable to successfully use tyre repair kits.
Manufacturer Policies – Verified UK Data
| Manufacturer | Standard Equipment | Paid Option | Source |
| Ford | Repair kit (most models) | Space-saver: £95 | Fleet News 2015 |
| Vauxhall | Repair kit (all models) | Space-saver: £95 | Fleet News 2015 |
| Volkswagen | Space-saver (majority) | Full-size on Golf Estate, Jetta, Passat | Fleet News 2015 |
| BMW | Run-flat tyres | No spare | Fleet News 2015 |
| Peugeot | Space-saver/Full-size (most) | Repair kits on 108, 3008, 508, 5008 | Fleet News 2015 |
| Nissan | Repair kit (Note, Qashqai, Leaf) | Space-saver on Micra, X-trail | Fleet News 2015 |
| Lexus | Space-saver (NX) | Fitted as standard due to fleet customer demand | Fleet News 2015 |
What the Repair Kit Can and Cannot Do – Technical Limitations
Tyre sealant is governed by ISO/TS 16969 and is designed for temporary emergency use only. It is not a repair. It is a get-you-home measure with specific limitations:
| Damage Type | Sealant Effectiveness | Reason |
| Puncture under 6mm, centre tread | Temporary seal possible | Small hole, low stress zone |
| Sidewall puncture | Zero | Flexing prevents bonding |
| Puncture over 6mm | Zero | Exceeds flow rate capacity |
| Run-flat tyre | Not applicable | Designed to run deflated |
| Tread shoulder | Zero | Edge flex prevents seal |
Manufacturer Warning – TPMS Damage
Hyundai Motor UK, in official owner documentation, states:
“It is recommended that you do not use a tyre sealant which is not approved by HYUNDAI. Tyre sealant not approved by HYUNDAI or the equivalent sealant specified for your vehicle may damage the tyre pressure sensor.”
Technical analysis confirms that sealant blocks the sensor’s pressure port and corrodes internal components. Replacement is the only remedy. Cost: £70–£120 per sensor, plus fitting.
Rental Industry Position
Enterprise Rent-A-Car and other major operators advise drivers not to use sealant. The rationale: sealant complicates damage assessment, creates cleaning liabilities, and frequently converts a repairable puncture into a full replacement tyre charge.
If rental companies – whose business model is minimising repair costs – discourage sealant use, the cost implication for private owners is clear.
Your Options – Verified
- Reinstating a spare wheel.
If your vehicle retains the physical wheel well, a spare can be purchased and fitted. Space-saver wheels are speed-restricted to 50mph and are not intended for long-term use. Full-size spares carry no speed restriction but require secure mounting hardware.
- Carrying a 12v compressor and plug kit.
A quality plug kit (reamer, insertion tool, rubber plugs) costs under £20. It does not contain liquid sealant and therefore does not risk TPMS contamination. Compressed air cannot fix a hole, but it enables you to reinflate and assess loss rate.
- Mobile tyre fitting.
Neither spare nor sealant is required if you have access to a mobile fitter who carries your tyre size and can attend your location. This is the only option that carries zero risk of sensor damage or unsuccessful repair.
Summary
Your car’s missing spare wheel is a regulatory outcome, not evidence that spare wheels are obsolete. The sealant kit is a compliance device, not a universal roadside solution.
Data confirms that repair kits fail frequently, that manufacturers warn against sealant use without approval, and that rental operators actively discourage their use.
You can put a wheel back. Or you can keep our number 00447448427154.
