BYD Seal U DM-i vs Kia Sportage PHEV: Price, Running Costs and Electric Range
Two plug-in hybrid family SUVs at a similar price point, answering the three questions UK searchers actually ask: which costs less to buy, which costs less to run, and which goes further on electricity alone. Cathay EV compares both against BYD's own China-market evidence and Kia's published UK figures.
The verdict
The Seal U DM-i undercuts the Sportage PHEV on price and out-ranges it on electric-only miles in its Boost and Comfort trims. The Sportage counters with a longer vehicle warranty and a much longer UK sales record.
Buy the BYD Seal U DM-i if
You want the lowest entry price, the longer electric-only range of the Boost or Comfort trims, or the deeper of the two battery warranties.
Buy the Kia Sportage PHEV if
You want the longer vehicle warranty, or you would rather buy from a brand with a longer established UK dealer network.
| Dimension | BYD Seal U DM-i | Kia Sportage PHEV |
|---|---|---|
| UK entry price | BYD Seal U DM-i£34,995 (Boost)Better here | Kia Sportage PHEV£38,595 (Pure) |
| Electric-only WLTP range | BYD Seal U DM-i50mi entry trim, up to 78mi (Design AWD lowest at 43mi)Better here | Kia Sportage PHEV44 miles |
| Vehicle warranty | BYD Seal U DM-i6 years or 93,750 miles | Kia Sportage PHEV7 years or 100,000 milesBetter here |
| Battery warranty | BYD Seal U DM-i8 years or 125,000 miles, 70% floorBetter here | Kia Sportage PHEV7 years or 100,000 miles, 70% floor |
| Euro NCAP rating | BYD Seal U DM-i5-star, adult 90%, VRU 83% | Kia Sportage PHEV5-star (2022), no category breakdown published |
Price: What Each Costs to Buy
The BYD Seal U DM-i starts at £34,995 for the Boost trim, rising to £36,995 for the Comfort and £39,995 for the all-wheel-drive Design. The Kia Sportage Plug-in Hybrid starts at £38,595 for the entry Pure trim. That puts the cheapest Seal U DM-i £3,600 below the cheapest Sportage PHEV. The comparison narrows or reverses further up BYD's own range: the mid-spec Comfort at £36,995 still undercuts the Kia by £1,600, but the flagship all-wheel-drive Design, at £39,995, actually costs £1,400 more than the Sportage's entry price. Both cars price under the £40,000 threshold that triggers the government's Expensive Car Supplement on Vehicle Excise Duty, though the Design does so by only £5, so neither buyer pays that extra charge in years two to six of ownership on the trims priced here.
Running Costs: Company Car Tax, Insurance and Real-World Economy
On the BYD side, insurance groups are 32 for the Boost and Comfort trims and 40 for the all-wheel-drive Design, and company car tax on the 2026 to 2027 Benefit in Kind schedule works out at roughly £43 a month for a 20% taxpayer in the Comfort, rising to about £58 for the Boost and £66 for the Design. Carwow's long-term test of the Seal U DM-i averaged around 40 miles per gallon when charged regularly. An insurance group and a CO2 figure for the Sportage PHEV are not established from the sources this comparison uses, so no company car tax or insurance figure is given for it here; a buyer weighing the two on running costs should get both direct from a dealer or an insurer before ordering.
| Attribute | BYD Seal U DM-i | Kia Sportage PHEV insurance group and |
|---|---|---|
| company-car tax | BYD Seal U DM-i2026-27 BiK, 20% taxpayer: about £43 a month (Comfort), £58 (Boost), £66 (Design); confirm exact P11D and CO2 banding before ordering | Kia Sportage PHEV insurance group andNot established from the sources this comparison uses; neither an insurance group nor a CO2 figure for this model appears there |
Also noted
- BYD Seal U DM-i insurance groupGroup 32 (Boost, Comfort); Group 40 (Design AWD)
- BYD Seal U DM-i real-world economyAbout 40mpg average when charged regularly (Carwow long-term test)
Electric Range and Charging
All figures here are the electric-only WLTP range, not a weighted combined mpg figure, and the two cars should never be read against each other on any other basis. The Seal U DM-i's Boost and Design trims cover 50 and 43 miles respectively on a smaller 18.3kWh battery, while the Comfort's larger 26.6kWh pack stretches that to 78 miles, among the longest electric-only ranges of any plug-in hybrid on sale in Britain. The Kia Sportage Plug-in Hybrid, on its own 13.8kWh pack, covers 44 miles electric-only WLTP on its Pure entry trim, a mile ahead of the Seal U's own Design trim though behind the Boost and Comfort. DC rapid charging tells a different story on the BYD side: 18kW maximum means a 30 to 80% top-up takes 35 to 55 minutes depending on battery size, offering little advantage over a 7kW home charger at a motorway services. Kia does not publish a DC charging figure for the Sportage PHEV at all; its own charging-time table lists this model only under AC columns.
| Attribute | BYD Seal U DM-i | Kia Sportage PHEV |
|---|---|---|
| DC charging speed | BYD Seal U DM-i18kW maximum DC; 30-80% in 35 minutes (18.3kWh) or 55 minutes (26.6kWh) | Kia Sportage PHEVNot published by Kia; the Sportage PHEV appears only in the AC columns of Kia's own charging-time table |
Also noted
- BYD Seal U DM-i electric-only WLTP range by trim50mi (Boost, 18.3kWh); 78mi (Comfort, 26.6kWh); 43mi (Design AWD, 18.3kWh)
- Kia Sportage PHEV electric-only WLTP range44mi (Pure, 2WD, 13.8kWh); distinct from the 104.6mpg weighted-combined figure on the same spec table
Warranty and Safety
Warranty is where the two split most clearly. The Seal U DM-i carries a 6-year or 93,750-mile vehicle warranty and an 8-year or 125,000-mile battery warranty with a 70% capacity floor, plus 12 years of bodywork cover. The Sportage PHEV carries Kia's standard 7-year or 100,000-mile warranty across the whole car, including the battery, with its own 70% capacity guarantee over that same period. So Kia's cover runs a year and 6,250 miles longer on the vehicle as a whole, while BYD's battery cover alone runs a year and 25,000 miles longer than Kia's. Both earn 5-star Euro NCAP ratings. Euro NCAP scored the Seal U DM-i at 90% for adult occupant protection, 86% child occupant, 83% vulnerable road users and 77% safety assist. The Sportage's own 5-star result dates to 2022, and Euro NCAP has not published a category breakdown for it, so this comparison states its star rating only rather than estimating one.
| Attribute | BYD Seal U DM-i | Kia Sportage PHEV |
|---|---|---|
| warranty cover | BYD Seal U DM-iVehicle 6yr/93,750mi; battery 8yr/125,000mi (70% floor); bodywork 12yr unlimited mileage | Kia Sportage PHEV7yr/100,000mi vehicle and battery together, with a 70% battery-capacity guarantee over the same period |
| Euro NCAP rating | BYD Seal U DM-i5-star: adult 90%, child 86%, vulnerable road users 83%, safety assist 77% | Kia Sportage PHEV5-star (2022); Euro NCAP has not published a category breakdown for this test |
China-side evidence
What China's Owners Say About BYD's Twin
The Seal U DM-i sold in Britain is the export version of the Song PLUS DM-i, a plug-in hybrid that has been on sale in China since 2021, so China's owner and complaint data speak directly to the hardware under this car's skin even though UK specification differs in places. On 12365auto, China's official vehicle-complaint platform, the Song PLUS DM-i carries a 2.5 out of 5 satisfaction score built from more than 3,530 logged complaints, with the largest clusters in body and electrical systems, engine and motor control, braking and suspension. Autohome, China's largest owner-review platform, gives the same car a considerably more positive 4.49 out of 5 from its own review base, praising fuel economy and cabin space while flagging suspension noise and winter range loss. The UK car differs from the Chinese one in three material ways: it drops the higher trims' God's Eye advanced driver assistance and Highway Navigate on Autopilot, it runs Apple CarPlay and Android Auto in place of China's Baidu Maps and DiLink software, and its warranty is time-and-mileage-limited where Chinese first owners get a lifetime warranty on the battery, motor and control unit. Kia's Sportage PHEV has no equivalent China-market data on the sources this comparison uses, so this page gives none rather than a guess.
Owner reports, complaint records and recall notices from the Chinese market, each with the source and the date we read it. Sample sizes are small; read them as signals, not survey results.
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Put the numbers to work
Turn a WLTP figure into a realistic UK winter range, or see what salary sacrifice saves on your tax band.