2024 (74) BYD Seal U 1.5 DM-i Boost 5dr Auto

The BYD Seal U DM-i extends PHEV tech into BYD's range. Jonathan Crouch takes a look.

Ten Second Review

The Seal U DM-i is BYD's first attempt at a Hybrid, a PHEV that aims to broaden the brand's sales base beyond EVs. It's possibly not the most exciting or engaging segment choice you could make, but value and practicality are both strong points that make this a family car worthy of consideration if you're looking at electrification but aren't quite ready for an electric vehicle.

Background

Just when we got used to the idea of Chinese maker BYD being an all-electric brand, along comes this car, the Seal U DM-i - a Plug-in Hybrid. You'd have thought the opposite approach - PHEV first, then EVs (as rival Polestar did) would make more sense. But BYD has its own way of doing things - as the unusual design of its first three EV models has shown. One of these was also badged 'Seal', a mid-sized EV saloon with premium aspirations that we really liked. We're not sure why the Plug-in Hybrid model we look at here also has a 'Seal' moniker because it shares virtually nothing with its EV showroom stablemate in terms of looks, price, powertrain or market positioning - the U DM-i is a five-door mid-sized SUV. The Seal U can also be had as an EV in other markets, but here to start with, we only get the DM-i PHEV version, the 'DM' letters standing for 'Dual Mode', BYD-speak for designation of the fact that an engine assists the electric drivetrain. Let's take a closer look.

Driving Experience

It's a little-known fact that BYD was the first manufacturer to mass-produce a PHEV - a model called the F3DM back in 2008 that hardly anyone bought. But the Chinese learn quickly and BYD can justifiably claim cutting-edge Plug-in Hybrid technology with this Seal U DM-i. The mid-range front-driven 'Comfort'-spec version can claim an EV range of up to 78 miles from its 26.6kWh battery before a frugal normally aspirated 1.5-litre petrol engine cuts in as you cruise past the queues at your local charging station. Still want that EV? This is one of three very different versions of the DM-i powertrain. There's an entry-level model badged 'Boost' (confusingly because its four cylinder engine is also normally aspirated). This variant uses the same 215bhp Atkinson cycle unit as the 'Comfort' model, aided by a single e-motor on the front axle and tuned for economy at low speeds. 'Boost'-spec though, mates this unit with a smaller 18.3kWh battery pack, with a still-reasonable EV range of 50 miles. The other Seal U DM-i model is the top 'Design'-spec version, tuned very much for performance. Here, the 1.5-litre engine gets a turbocharger and switches to the Miller cycle aimed at high speed frugality. Plus an extra e-motor is added to the rear axle to create AWD. Power jumps to 319bhp, improving the 8.9s 0-62mph sprint time you get with the front-driven models to just 5.9s. The 'Design' version supplements the usual 'Eco', 'Normal' and 'Sport' drive modes with extra 'Mud' and 'Sand' settings too. The battery on offer is the smaller 18.3kWh one and is supposed to deliver up to 43 miles of EV range. Expect the drive experience to be very EV-like - the complicated powertrain ensures that there's always a minimum battery charge of at least 25%. But don't expect the engaging driving dynamics we enjoyed with the Seal EV saloon. Seal U has a soft ride and light steering, but compensates with effective brakes and outstanding refinement.

Design and Build

After the avant-garde design that characterised the Seal EV saloon, the Seal U is surprisingly conservative to look at, though the Chinese maker insists that it's fashioned using the same 'Ocean aesthetics' design language. Which is supposedly highlighted by a prominent belt line that runs from the headlamps to the tail lights. Horizontal lines stretch across the nose, while the rear gets one of those currently fashionable full-width light strips. BYD has toned down the design aesthetics inside too. There's still that brand signature - an enormous rotating central screen, this one 15.6-inches in size. And you get the small bejewelled drive shifter from the Seal EV. But otherwise, things are a bit more class conventional - by BYD standards anyway. There's a large instrument screen that's slightly over-busy with information and a useful quick-access feature on the central monitor more easily turns off some of the more intrusive safety aids. A head-up display is standard, along with the usual parking aids, which you'll need because rearward vision is restricted by the small rear window. The long wheelbase means there's plenty of rear leg room, with space for up to three adults. The 450-litre boot isn't the biggest in the class and isn't supplemented with any extra under-floor space to store the charging cables, but it'll probably be sufficient for most owners.

Market and Model

The Seal U is priced quite a slug below the Seal EV saloon. There are no trim levels: just the three powertrain options, base 'Boost' (with the 18.3kWh battery), mid-level longer-ranging 'Comfort' (with the 26.6kWh battery) and top AWD 18.3kWh 'Design'. Think in terms of pricing starting from around £34,000 and ranging up to around £39,000 for the 'Design' variant. That significantly undercuts obvious rivals like PHEV versions of the Volkswagen Tiguan and the Toyota RAV4. All derivatives come absolutely stuffed with equipment. Things like a head-up display, an enormous rotatable 15.6-inch infotainment screen, a Harmon Infinity premium audio system, heated and cooled seats and two wireless charging mats. There's also faux leather upholstery and vehicle-to-load functionality so that you can plug external devices into the vehicle's drive battery. In terms of safety and advanced driver assistance, the Seal U offers Forward Collision Warning, Automatic Emergency Braking, Rear Collision Warning, Rear Cross Traffic Alert and Rear Cross Traffic Brake, Lane Keep Assistance, Lane Change Assist and Emergency Lane Keep. There's also Adaptive Cruise Control and Intelligent Cruise Control, a Blind Spot Detection System, ESP, Traction Control, Hill Decent Control, Automatic Vehicle Hold, Intelligent Speed Limit Information and Intelligent Speed Limit Control.

Cost of Ownership

The 18.3kWh and 26.6kWh batteries used here can be either AC charged at up to 11kW or DC charged at up to 18kW. Charging from a DC public charger from 30 to 80% takes around 35 minutes using an 11kW charger. It's likely to take a bit longer than that with the 7.4kW wallbox your home is more likely to have. We gave you the drive range figures in our 'Driving' section: 50 miles for the 18.3kWh base 'Boost' model, 78 miles for the 26.6kWh 'Comfort' version and 44 miles for the AWD 'Design' derivative. The 'Boost' variant has a quoted combined consumption figure of 314mpg, but you're not likely to achieve that outside of a laboratory. A more realistic stat is that base variant's total range figure of up to 621 miles. The AWD top 'Design' flagship version will officially do 235mpg on the combined cycle and has a theoretical total range of 541 miles. There's a better warranty than you get from most rivals - up to six years or 93,750 miles, with an extra two years for the drive unit and the battery. That battery is covered for up to 125,000 miles and is guaranteed to retain at least 70% of its capacity throughout the warranty duration.

Summary

There's lots you might conceivably like here. The smooth powertrain should feel very much like the EV this Seal U will be on most commuting journeys. There's also lots of rear seat space, decent cabin quality and loads of equipment. Plus the EV claimed mileage of the longer-ranging 'Comfort' model is difficult to better in this class of mid-sized PHEV. We can't help being a little disappointed though, that the avant-garde design and sharp handling of the Seal EV saloon wasn't replicated here. Still, quite a few likely customers won't care very much about that and if you don't and want a family EV alternative, this Seal U DM-i certainly merits a place on your shortlist for mid-sized PHEVs.