Should you buy one?

Yes. The BYD Seal 6 is a very interesting addition to the plug-in hybrid saloon market. It’s much more affordable than the Skoda Superb PHEV, it offers far more boot space than the BMW 330e and it arguably makes better sense for long distance drivers than any of its rivals due to how efficiently it rations out its battery power.

Deciding whether you should buy a BYD Seal 6 depends upon where you sit on the intersection between driving dynamics and practicality. If all you need your plug-in hybrid saloon to do is be efficient, spacious and (reasonably) comfortable at speed, you’ll find a lot to like about the Seal 6. Especially for £33,000. It’s a proper bargain.

However, if you value a polished powertrain, consistently good ride quality and engaging driving dynamics, you’ll likely have a greater affinity for the 330e. I know I do, even though the BMW has a steeper starting price, a smaller boot and a slightly lower electric range. I value how well it’s been nailed together and that it’s far better to drive.

What’s new?

Looks can be deceptive. The Seal 6 DM-i’s exterior styling might share a strong family resemblance to the pure-electric Seal saloon, but it’s aimed at a completely different audience. Instead of a massive battery pack and huge electric motor, it’s powered by the same sort of plug-in hybrid system fitted to BYD’s Seal U DM-i SUV.

Much like the Seal U, it’s designed to appeal to long-distance drivers who like the idea of electrification, but whose high-mileage schedules make it inconvenient to own an electric car. Plus, unlike almost every other electric car in the class, the Seal 6’s powertrain has been calibrated to use its electric power gradually rather than in one hit, meaning you should spend less time dragging around the dead weight of a depleted hybrid system. That’s clever.

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BYD has made some significant changes to its cabin design language for the Seal 6, too. It’s a lot simpler than the electric Seal’s, with fewer colourful materials and more hard plastics, both of which help to drag the Seal 6’s starting price down to £33,000. The brand has also junked its rotating screen for a conventional unit in the centre of the dash. But, as I’ll explain below, that’s not such a bad thing.

What’s it like inside?

In place of its trademark rotating infotainment system, buyers now have a choice of either a 12.8 or 15.6-inch landscape touchscreen, which I think is more useful more of the time.

Granted, BYD’s rotating screens allow you to plan further along your route when in portrait mode – but the fact that setting isn’t compatible with Apple CarPlay or Android Auto has always defeated the point of the exercise for me. I don’t know anyone who prefers to use their car’s built-in navigation app over Google Maps or Waze.

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Plus, BYD’s rotating screens are quite exposed and I’ve long been concerned about their sturdiness. You can apply a lot of stress to the mount by using the screen as a lever – and if you lean on it too heavily, I reckon you (or a particularly destructive toddler) could heave it off the dashboard. The Seal 6’s integrated screen should be more difficult to break.

If you’re a technophile who’s disappointed by this change, don’t worry because BYD has tried to compensate for it in other areas. Take the Seal 6’s wireless phone charger as an example. It has a built-in cooling vent to prevent your phone from overheating – and it works very well. I left my phone on the charger all day and it didn’t boil over once.

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Then there’s the passenger space. It’s here where the Seal 6 really gets into its stride. Rear legroom is positively palatial. I’m six feet tall and, with the seat in my driving position, I had a solid four inches of space between my knees and the seat ahead.

Foot space is similarly generous because BYD has packaged the Seal 6’s platform cleverly enough to not need an exhaust hump in the centre of the floor pan. Normally, you need to buy an electric car for this luxury.

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If that wasn’t enough, boot space is far better than our favourite plug-in hybrid saloon, the BMW 330e. You get 491 litres in the Seal 6 compared to just 375 litres in the 330e. So, if you want a spacious and efficient saloon (and you’re not that interested in driving dynamics), the Seal 6 should serve you well.

BYD Seal 6 DM-i saloon engines

The Seal 6 is powered by BYD’s augustly named ‘Super Hybrid’ system. It teams the brand’s own 1.5-litre four-cylinder petrol engine with a pair of electric motors – and you can choose between two battery sizes and two power outputs depending on the trim level you specify.

The cheapest Boost model produces 184hp and its 10kWh battery pack offers maximum electric range of 34 miles. BYD’s pricier Comfort Lite and Comfort models both produce 212hp, while their larger 19kWh battery packs increase maximum EV driving range to 65 miles. That’s a long way behind the 85-mile electric range Skoda claims for the Superb PHEV, but BYD reckons the Seal will be more efficient on long journeys as it was designed to ration out its battery power slowly rather than blow through it all in one hit.

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It has a maximum WLTP driving range of around 900 miles – a claim I found to be surprisingly accurate. I achieved more than 50mpg during my time with the car without driving especially economically. Combine that efficiency figure with the car’s 65-litre fuel tank and 65-mile electric range, and that provides a theoretical maximum range of almost 800 miles. That’ll give a diesel Superb a good run for its money.

What’s it like to drive?

Good, mostly. However, like almost every Chinese car I’ve driven this year, it could do with a little more polish to make it perfect. I also reckon some of these oversights are severe enough to push some drivers back towards more practiced European OEMs.

My biggest issue with the Seal 6 is the way it rides. It isn’t desperately uncomfortable, but it’s never settled, either. On the French B-roads I found during my test drive, the suspension was constantly nudging me between the seat bolsters like a pinball – and that gets tiring after the first 20 miles. If you live somewhere rural, that’d be enough to justify spending the extra money on the more forgiving Skoda Superb.

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There is a benefit to the firm damping, though. The Seal 6 stays surprisingly flat when you hurl it at corner. The trouble is, the numb steering never encourages you to explore the limits of the chassis’ capability. It doesn’t offer enough feedback to brim you with confidence, so I’d be happy to trade this tight body control for greater compliancy.

Thankfully, once you steer off the B-roads and onto the motorway, the Seal 6 settles down into a more refined cruise. The ride smoothes out well as you pile on the speed and, by the time you’re belting down the motorway, it’s perfectly acceptable.

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BYD has worked hard to keep the cabin quiet, too. Road and wind noise are kept in check by the sound deadening and door seals, and because the electric motors are punchy enough to move the car around on their own, the engine spends most of its time barely ticking over. It only wakes up when you ram your right boot into carpet, at which point the engine will scream like you’ve just shifted from fifth to third at 70mph. This happens infrequently enough to be forgivable, though.

What’s less forgivable is the length of time it takes for the engine to respond when you tread on the throttle. Syncing the motors with the direct drive from engine is quite a delicate operation, but BYD hasn’t engineered the solution very elegantly. It takes a good two seconds for the for the engine to deliver its performance, which is just long enough to lose your window of opportunity for an overtake. Honda’s e:HEV system, (which works on similar principles to BYD’s setup), is far more sophisticated. I suppose you get what you pay for.

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But the worst part about the driving experience is the driver monitoring technology. There’s a little camera mounted on the A-pillar that tracks your eyes to check you’re still paying attention to the road. It’s a sound idea in principle, but BYD has made it far too sensitive.

By the time I’d completed my first kilometre, the sensor had reprimanded me no less than five times for such heinous offences as checking my mirrors, scratching my head and reading navigation instructions off the touchscreen. More calibration is needed if BYD doesn’t want its owners to disengage the tech every time they get behind the wheel.

What models and trims are available?

There are three specifications to choose from, called Boost, Comfort Lite and Comfort – and, in typical fashion for BYD, they’re all well-equipped. The most basic car comes as standard with electrically adjustable front seats, a 12.8-inch infotainment system, air conditioning and a wealth of driver assistance technology.

In my opinion, the Seal 6 makes better sense the further up its pecking order you climb. So, the top spec saloon costs between £35,000 and £36,000, but it gets heated and ventilated front seats, a panoramic sunroof, a 15.6-inch infotainment system and BYD’s most powerful PHEV system. That’s truly staggering value when you compare it to the £50,000 you’d spend on a similarly well-equipped BMW 330e.

Now click through to our verdict page for a breakdown of the BYD Seal 6’s key strengths and weaknesses and our list of scores for the car. If you’re keen to learn more about how we arrived at our verdict, check out our how we test cars explainer page.