BYD Seal vs MG IM6 (UK, 2026): Premium Saloon Showdown — Range, Charging and What Chinese Owners Really Say

The BYD Seal opens at £45,730 for the Design (rear-wheel drive), with the dual-motor Excellence at £48,730. The MG IM6 Long Range starts at £48,495 — a £2,765 gap at the base — with Performance at £51,495 and the Launch Edition at £53,495.

On the Expensive Car Supplement, the MG IM6 Long Range (£48,495) slips just under the £50,000 threshold and escapes VED's ECS entirely for years 2 to 6. That saves £355 per year compared with an equivalent car over £50k. The Seal Design (£45,730) also sits below the threshold. The Seal Excellence (£48,730) and all three IM6 trims above Long Range do attract the ECS.

For company car drivers, both EVs attract 4% Benefit-in-Kind in 2026/27, making the Seal's lower list price the slightly cheaper salary-sacrifice option at entry level. Insurance groups are comparable — group 48 for the Seal Design and group 50 for the IM6 Launch Edition (AWD, tested by GreenCarGuide).

The MG IM6 Long Range has a 388-mile WLTP figure against the Seal Design's 354 miles — a 34-mile advantage on paper. In the real world, What Car? testing returned 299 miles for the IM6 Long Range; the Seal Design is broadly comparable at around 270–300 miles in mixed driving at UK motorway speeds.

The bigger divergence is on charging. The IM6 uses an 800V architecture with a claimed peak of 396 kW — real-world measured average is closer to 250 kW per EV Database, with a 10–80% time of roughly 17 minutes at a 350 kW charger. The Seal peaks at 150 kW (Auto Express measured 123 kW in real testing), with 10–80% taking around 37 minutes. If you cover more than 150 miles at a stretch and regularly stop at rapid chargers, the IM6's charging speed advantage is a genuine differentiator on the motorway.

On V2L, the Seal holds confirmed 3.3 kW vehicle-to-load capability as standard — useful for camping, tools, or powering devices in a power cut. The IM6's V2L status is disputed in UK sources: Electrifying.com and EV Database list no V2L; GreenCarGuide and EVGuide.uk say it is present. Do not rely on V2L from the IM6 without dealer confirmation.

Neither car has battery preconditioning on AC charging. The Seal lacks preconditioning entirely, which can reduce DC peak speeds in cold weather.

BYD Company Ltd makes the Seal directly. There is no shell company, no rebadge, and no distributor sitting between you and the manufacturer. BYD is the world's second-largest EV producer by volume, publicly listed in Hong Kong and Shenzhen (HKEX: 1211), and sold over 4 million vehicles globally in 2024. It manufactures its own Blade Battery cells, electric motors, and semiconductors in-house — reducing third-party supply-chain fragility. The UK dealer network is established, with the Seal having been on sale since late 2023. Brand survival risk is among the lowest in the Chinese EV segment.

The MG IM6 is more layered. It is built by IM Motors (智己汽车), a joint venture between SAIC Motor, Alibaba Group, and Zhangjiang Hi-Tech Park — established in 2020. The car carries the MG badge for UK distribution through MG Motor UK, which itself is wholly owned by SAIC. SAIC is one of China's largest legacy automakers and has had a UK presence for over a decade. Survival risk is low given SAIC's scale, but you are effectively buying an IM Motors product through an MG distribution chain — an extra step compared with BYD's direct model.

On warranty, the gap is material. The BYD Seal offers an 8-year/155,350-mile battery guarantee, with a minimum 70% state of health at claim — and this was retroactively extended to existing UK Seal owners in January 2026. The MG IM6 covers 7 years or 80,000 miles (vehicle and high-voltage battery) according to two UK-specific sources from July 2026. Some third-party databases quote longer terms; use 7yr/80k for planning until IM Motors UK publishes a clearer specification on its own website.

China is where these cars have been on sale the longest, and Chinese owner data is one of the most useful signals available to UK buyers. Both models have enough domestic history to give a meaningful picture.

For the BYD Seal (比亚迪海豹), Autohome rates it 4.27 out of 5 from 201 owners — a solid result in a competitive segment. The Vehicle Quality Network (车质网) scores it 87 out of 100. Owner praise clusters around long range, strong acceleration, comfortable suspension, and generous front headroom. Complaints run to wind noise, tyre noise, limited rear headroom, and a small boot opening — the latter addressed by the MY26 UK car's enlarged 485-litre boot. The fault-rate figure (325 per 100 cars) comes from only eight survey respondents and should be treated as indicative rather than definitive.

The MG IM6 (sold in China as the IM LS6) is a significantly different picture. Its 车质网 satisfaction score is 2.1 out of 5.0 — the lowest in this price segment by some margin. Around 509 complaints across model years 2023–2026 cover: paint bubbling and peeling (most frequent); ADAS camera fogging in humid conditions; white powder discharging from air vents (an evaporator coating issue also reported in the MG4); premature and uneven front tyre wear; and infotainment screen blanking. The manufacturer response rate is 95.2%, which suggests cases are being processed — but the volume and the pattern matter. Cumulative IM LS6 deliveries exceeded 100,000 by January 2026, making the raw complaint count less than 0.5% of the fleet — context worth keeping.

For the UK specifically: the ADAS camera-fogging complaint is directly relevant in Britain's damp climate. Paint quality should be inspected at handover.

Both cars lose their most capable driver-assistance hardware on the way to Britain. China's BYD Seal Smart trims carry 96-line LiDAR and NVIDIA Orin X for highway NOA — absent from the UK car. The IM LS6's upper trims in China include LiDAR and NVIDIA Orin-X or Thor-U; the UK IM6 is camera-only L2 ADAS. Neither manufacturer discloses this gap prominently in UK marketing.

The BYD Seal earned a Euro NCAP five-star rating in 2023 — Adult Occupant protection 89%, Child 87%, VRU 82%, Safety Assist 76%. However, the 2023 test documented one material concern: following a power disconnect, the car's windows could not be opened — a submersion risk in flood scenarios. BYD has not confirmed whether MY26 cars resolve this. This is a verified safety finding from the official NCAP assessment, not speculation. Buyers who live near flood-prone roads, or who carry children in the rear, should note it explicitly.

The MG IM6 earned a more recent five-star rating in September 2025 — Adult 90%, Child 85%, VRU 83%, Safety Assist 87% — with no equivalent submersion concern on record. In the UK, one detailed early reliability report from the MG EVs forum (April 2026) describes a cascading 12V battery and ECU failure at 4,500 miles, requiring multiple replacement parts and nine and a half weeks off-road. No recall or widespread pattern has been confirmed; this is a single owner account, included because the failure mode was significant.

On interior practicality, the IM6 has a meaningful advantage: 665-litre boot (Long Range) versus the Seal's 485 litres — a near-30% difference that matters if you regularly carry bulky loads.

In summary: buy the BYD Seal if you want the longest battery warranty in the segment (8yr/155k), confirmed V2L at 3.3 kW, a lower entry price, and the most vertically integrated Chinese EV company behind it. You will live with 150 kW charging rather than 800V ultra-fast, and you should be aware of the NCAP submersion finding.

Buy the MG IM6 if 800V ultra-fast charging, maximum WLTP range, a larger boot, and a more recent NCAP assessment are your priorities. You accept a shorter warranty (7yr/80k), an unresolved V2L question, the weakest Chinese owner satisfaction score in this segment, and a one-step distribution chain through MG rather than the manufacturer.