Styling
BYD will offer the Seal 6 DM-i in two body forms, the regular saloon and then this Touring estate. Neither are going to set the world of car design on fire, you understand, but by the same token neither of them are particularly offensive to look at. The Touring is marginally the more attractive, even though its longer roof doesn't make the car any bigger from tip to tail than the saloon, and the smoothed-off, aeero-focused styling that ties it in with other Seal and Sealion products ensures that the 6 DM-i has an impressive coefficient of drag of just 0.284. Base Boost models sit on 17-inch alloys, while the higher-grade Comfort enjoys 18s, although it's a shame there are just four colours available for the BYD - Polar White, Sandstone, Atlantis Blue and Obsidian Black, all of which are metallic. Polar is the standard hue but as metallic paint is standard on all Seal 6 models, it won't cost you anything to opt for one of the other three shades instead.
Interior
There's some visual appeal to the design of the BYD Seal 6 DM-i's interior, while material quality is generally OK too, although there are a few areas (the column stalks in particular) where you'll pick up that this is a budget-biased car. All models have an 8.8-inch instrument cluster and, for the base version, there's a decent 12.8-inch infotainment screen, which is uprated to a 15.6-inch item in the Comfort as tested here (but the screen doesn't rotate, before you get too excited). In the main, these work well enough but there's still too much on the central display - such as the climate controls - and therefore you'll be tapping away at the screen too often for comfort; quite simply, some physical buttons would do many of these jobs in a far more straightforward manner. This frustration with the infotainment includes the times when you are operating either Apple CarPlay or Android Auto wirelessly, and you want to switch back to some of the proprietary onboard apps; it's not always the most intuitive segue from one screen to another.
Practicality
There's lots of interior storage in the BYD Seal 6, while rear passenger space looks at first to be rather generous. But due to the height of the bench squab and the way the rear seatbacks are reclined, it's not the most comfortable seating position back there for taller occupants - and there isn't a lot of room for feet underneath the front seats either. A 500-litre cargo bay in this Touring is only nine litres more than the saloon possesses, although bear in mind the four-door BYD's boot aperture is a narrower, lower opening than the full tailgate of the estate. At 1,535 litres with the rear seats folded, the Seal 6 has a reasonable amount of loadspace, but it's still a good 235 litres shy of a Skoda Superb Estate with a PHEV powertrain.
Performance
Both versions of the DM-i, which is BYD-speak for 'PHEV' (it stands for 'Dual Mode, intelligent'), are front-wheel-drive machines with a CVT fitted to transmit power to the road. They both have 1.5-litre normally aspirated four-cylinder petrol engines that deliver 98hp/122Nm, accompanied by a 145kW electric motor which can generate another 300Nm. It's this latter torque figure that is cited as the system max for both variants.
The difference between the Seals is that the entry-level Boost has a lesser 184hp output, plus a smaller 10.08kWh lithium-ion battery pack and no capability to charge up via DC rapid methods. It'll do around 31 miles on electric power alone, with a peak charging rate of 3.3kW AC.
Meanwhile, the Comfort increases the battery to 19kWh, which doubles the electric range to 62 miles, and it'll top up its battery at either 6.6kW AC or a maximum of 26kW on a DC connection. Power climbs to 212hp overall, but because the larger collection of power cells raises the weight of the car by 95kg, the 0-62mph time is trimmed by just four-tenths of a second (8.9 for the Boost and 8.4 seconds for the Comfort). The combined range of every Seal 6 DM-i Touring is said to be in the region of 840 miles, without need to visit either petrol pump or public charging point.
This would all be fine, were the Seal 6 not so bleedin' slow. It never, ever feels like a car capable of a 0-62mph time of less than ten seconds, never mind eight-and-a-half, and yet if you're sometimes a little too eager with the throttle coming out of corners then you can beat the traction-control electronics and experience scruffy wheelspin. The brakes are even less appealing, because they can either be grabby at low speeds or have masses too much pedal travel and not enough bite at higher pace; they're inconsistent, essentially, the worst trait to have in a set of stoppers.
Layered on top of this is the unresponsiveness of the drivetrain, plus the grating noise of it. Slap the throttle down quickly and there are entire seconds to wait until the CVT has let the noisy, harsh and weedy 1.5-litre engine rev out, so once you are accelerating at what turns out to be only a modest speed, you're greeted with an unrefined, thrashy din from the drivetrain. If you never press the right-hand pedal down more than about 20 per cent at a time in the BYD and you can mainly surf around on its electric power, then yeah - it's just about acceptable. For all other uses and driving conditions, this is not a great powertrain. And that's understating things somewhat.
Oh, and it achieved a pretty middling 46.3mpg during our test drive, which mainly involved a steady cruise down the M4 on a constant throttle. The BYD had plenty of battery reserves left, incidentally, and the company says its DM-i system cleverly ekes out its resources so it doesn't just chomp through all its electricity in the first, say, 50 miles, and then spends the rest of its time running on petrol. Thus, the fact it couldn't even match the reasonable printed claimed average of 56.5mpg is all the more alarming.
Ride & Handling
Dear, oh dear, oh dear. This is one of those unfortunate cars that does neither ride nor handling well. The suspension set-up on it is loose and slovenly, so not only does the Seal 6 crash and wallow about when it's trying to cover off lumps and bumps in the road, making it a vehicle that is comfortable nowhere (not in town, not on country roads, not on trunk routes and not when rolling along a motorway), but it's all imprecise and wayward if you decide to chuck it into a few corners. Mind, the steering will discourage you from doing that, because it is almost completely devoid of any meaningful feel or weighting. There's no point labouring this point: on the move, the BYD Seal 6 DM-i, in either Boost or Comfort spec, and no matter whether it is optioned as a saloon or a Touring, is a deeply unpleasant thing in which to be travelling. BYD has already proven it can do far better chassis tuning than this underbaked effort. Avoid.
Value
It's £3,000 to upgrade a basic Seal 6 DM-i Boost to Comfort spec, and then another £1,000 to switch the saloon body to that of a Touring. Therefore, the prices are £33,990 and £34,990 for the Boost models, and £36,990 and £37,990 for the Comfort cars. Absolutely everything that's available on each spec is standard-fit, so there are no cost options whatsoever - not even, as we said higher up the piece, metallic paint. What you see is what you pay.
Obviously, this makes the BYD considerably cheaper than any vaguely similar-sized PHEV on the market from more established manufacturers, and you get a heck of a lot of equipment on even a Boost, with a Comfort loading in the luxuries to tempt in buyers. Yet we'd argue for the utterly sub-par driving experience the Seal 6 DM-i serves up, it is not nearly cheap enough to justify you ignoring far more talented European and Japanese rivals to end up with it, frankly.
Verdict
Yes, sure: the BYD Seal 6 DM-i Touring Comfort is cheaper than, say, a
Skoda Superb iV Estate. But that's like saying that a rundown two-bed semi in Hartlepool town centre is better than a four-bed home with sea views in Devon, because they're both houses and one is cheaper than the other. You can pick the BYD over the Superb if you must, and if the saving of a few thousand pounds is the absolute be-all and end-all to you when it comes to purchasing decisions then we guess you can legitimise plumping for this Chinese machine. But you'll have to swallow some serious dynamic compromises if you end up with the badly flawed Seal 6 DM-i. We'd rather just have the Superb, if we're honest, which is vastly superior to this BYD in every single regard.
