Smart #5 vs BYD Atto 3 EVO (UK 2026): £810 apart — which one's actually better?

Both cars are Chinese-made, but from very different ownership structures.

The Smart #5 comes from Zhima Motors (智马达汽车有限公司), the 50/50 joint venture between Geely and Mercedes-Benz. Mercedes-Benz's global design team shaped every surface; Geely supplies the platform, manufacturing and battery engineering. The JV structure means two of the world's largest automotive groups are each betting on Smart's success. Neither can easily walk away unilaterally. Brand survival risk is very low.

The BYD Atto 3 EVO is a wholly BYD product. BYD is the world's largest EV maker by volume, vertically integrated to a degree unusual even among global carmakers — it designs and manufactures its own Blade Battery cells, semiconductors and drive motors. BYD is publicly listed in Hong Kong and Shenzhen, profitable, and sells into over 100 countries. It also supplies battery cells to Tesla, Toyota and Mercedes-Benz. Brand survival risk: very low.

For a UK buyer choosing between them on brand-durability grounds, both are safe. Smart has institutional backing; BYD has sheer scale. The Atto 3 line has over 1.1 million units sold globally — that is a volume that creates genuine real-world reliability data and a mature supply chain. The Smart #5 is newer and lower-volume, though it carries the institutional credibility of the JV.

The Smart #5 Pro starts at £39,800 and the BYD Atto 3 EVO starts at £38,990 — a gap of just £810. That headline similarity conceals very different propositions.

The Atto 3 EVO at entry gives you a 316-mile WLTP range, a 74.8kWh Blade Battery on a 800V platform with 220kW DC charging, and BYD's 8-year/155,350-mile battery guarantee. It is a complete, mature package at the entry price.

The Smart #5 Pro at entry is the 400V/76kWh/150kW-DC variant — the less capable architecture in the Smart range. To get the 100kWh/800V/400kW platform with 366-mile WLTP range, you step up to the Pro+ at £43,800. At that point the Smart #5 is £4,810 more than the Atto 3 EVO entry.

For salary-sacrifice users, both benefit from low BiK rates: 3% in 2025/26, rising to 4% in 2026/27. The Smart #5 Pro P11D of approximately £39,745 gives a 20% taxpayer annual BiK cost of around £318 for 2026/27. The Atto 3 EVO at £38,990 is marginally cheaper.

Residual values for both brands remain uncertain in the UK used-EV market, though BYD's greater volume and established dealer network gives it a modest structural advantage.

This is the most important technical difference between the two cars, and it depends heavily on which Smart #5 trim you buy.

The BYD Atto 3 EVO is consistently 800V across the range: 220kW DC peak charging, 10–80% in approximately 25 minutes, and 316 miles WLTP from the 74.8kWh Blade Battery LFP. Real-world efficiency runs to about 3.4 mi/kWh in mild conditions, so a 250-mile motorway day is comfortable.

The Smart #5 has a deliberate architecture split. The Pro (£39,800) uses a 76kWh LFP/400V platform with 150kW DC — adequate, but noticeably slower than the Atto 3. The Pro+ and above (£43,800+) switch to 100kWh NCM/800V with 400kW DC peak and 18-minute 10–80%. Auto Express winter tested the Pro at 179 real-world miles; the 100kWh variants fare considerably better, reaching around 320 miles real-world in temperate conditions (GreenCarGuide, 2025).

The Smart #5's Achilles heel — identified consistently by every UK tester — is efficiency. Auto Express's winter test returned only 2.4 mi/kWh from the Pro, versus 3.6 for the Tesla Model Y tested at the same time. That gap closes the range advantage on the 100kWh trims significantly.

For long-distance UK drivers on a budget, the Atto 3 EVO at £38,990 delivers consistent 800V charging. The Smart #5 Pro at £39,800 gets you a lesser architecture; you pay a further £4,010 to match Atto 3's charging capability.

Safety first. The Smart #5 has been independently tested and scored 5 stars in Euro NCAP 2025: adult 88%, child 93%, VRU 84%, safety assist 92%. That is a strong, current result under the 2025 protocol — one of the tougher testing frameworks NCAP has used.

The BYD Atto 3 EVO situation is more complex and Cathay EV has flagged it consistently: the original Atto 3 scored 5 stars in 2022 under older protocols, but Euro NCAP re-tested it in September 2024 and issued a 'Not Recommended' for assisted driving — it lacked driver monitoring. BYD updated the 2025 model year with Bosch ADAS hardware. The 2026 Atto 3 EVO has not been re-tested under the current protocol. BYD's marketing still references the 2022 five-star rating. UK buyers should be aware of the gap.

On warranty, positions reverse. The Smart #5 vehicle warranty is three years (unlimited mileage), the shortest in its price class. BYD offers six years / 93,750 miles on the vehicle — double Smart's coverage. Battery warranties: Smart gives 8 years/125,000 miles with a 70% SoH floor; BYD gives 8 years/155,350 miles on the same 70% SoH floor — 30,350 miles more.

For a family keeping the car beyond three years, the Atto 3 EVO's vehicle warranty advantage is meaningful. For those changing cars every 2–3 years, Smart's coverage is adequate.

The Smart #5 and BYD Atto 3 EVO are both credible Chinese EVs from brands with excellent long-term survival prospects. The right choice comes down to three decisions: warranty expectations, charging architecture, and driving style.

**Choose the BYD Atto 3 EVO if:** You want a longer vehicle warranty (6yr vs 3yr) and consistent 800V fast charging across all variants without paying extra. The Atto 3 EVO is the more straightforward buy — what you see at £38,990 is what you get: 316-mile WLTP range, 220kW charging, and a well-tested (if NCAP-caveated) family SUV. BYD's scale and UK dealer presence adds a layer of service confidence.

**Choose the Smart #5 if:** You want What Car?'s Family Electric SUV of the Year award winner, the cleanest NCAP 2025 safety certification in this comparison, and you're buying the Pro+ or above (£43,800+). The Smart #5's 100kWh/800V/400kW variants are genuinely excellent long-range machines. The Pro at £39,800 is more compromised — lower range, slower charging — and you pay nearly £4k more than the Atto 3 for that lesser powertrain.

**Key caveat:** The Atto 3 EVO has not been re-tested by Euro NCAP under current 2025 protocols. BYD's marketing still references the 2022 five-star rating, which is outdated. Smart #5's 5-star 2025 result is current and trustworthy. If safety certification is your primary criterion, the Smart #5 wins clearly.

**Three-year warranty watch:** Smart's 3-year vehicle warranty is the shortest in the price bracket — shorter than Kia, Hyundai, MG, BYD and Leapmotor. If you are buying rather than leasing, and you plan to keep the car beyond three years, the Atto 3 EVO's six-year coverage is materially better.