BMW 428i vs BYD Sealion 5

What's the difference?

The 4 Series line offers three distinct points of difference from the more traditional 3 Series, each with their own attraction. The sharpening of the sticker prices and the additional spec helps their cause as well, with the 430i Coupe probably our pick of the range. The 440i is the firecracker of the group, while the 420d is also worth a look, thanks to its value and prodigious torque output.

Cars that don’t always appeal to enthusiast buyers are often seen by manufacturers as a way of not bothering with the dynamics. Good enough is, apparently, good enough. Thankfully, BYD hasn’t taken that path here and the local suspension tweaks have turned what could have been a me-too product into a bit of a dynamic class leader. And even if buyers can’t verbalise the benefits of that, they will still be subliminally enjoying them with every kilometre.

The other stand-out feature is the price-tag which represents an awful lot of car for the money. And, in such a price-sensitive market as this one, that will get the BYD over the line for a lot of families. That it also offers a vastly better driving experience simply makes the value equation – and the purchasing proposition – even stronger.

No external changes to the 4 Series' bodywork have been affected  for  this midlife refresh, but there have been plenty of tweaks to the standard equipment offerings right across the board.

The interior of the Sealion 5 feels pretty well-made and there are soft-touch surfaces on most of the touch-points. The steering wheel, too, is thick and chunky and nice to hang on to. But there’s a lot going on in terms of different colours, textures and surfaces, and it can all look a bit busy, despite the high-tech boardroom overall flavour. It’s also worth mentioning the trim material is synthetic but does a great job of looking and feeling like real leather.

Externally, there’s not a lot to grab the eye. Sure, it’s not an unpleasant looking vehicle, but neither does it stand out from the mid-size SUV pack. At least BYD decided against those cheap-looking plastic tack-ons on each wheel-arch.

Two-doors are never the most practical devices, but the 4 Series Coupe and Convertible duo make a decent fist of it for front-seat passengers. There are bottle holders in both doors and a pair of cupholders in the centre console, along with a large lockable glovebox.

The centre bin is, however, quite shallow, and houses the car's single USB port inside it. There is covered storage under the dash for smaller items, and a small rubber-lined tray that the current crop of phones has outgrown.

The rear seating in the Coupe is reduced to almost a formality, especially if the front seat passengers are tall and the front seats are set back, while the sloping roofline reduces head space quite considerably. A centre armrest contains a pair of cupholders, and there are small side pockets.

Rainy conditions precluded us from trying the Convertible's metal folding roof, but the rear seat space restrictions also apply here. Its 370 litres of boot space is roomy enough for a drop-top, while a clever lifting function raises the folding roof structure up by about 300mm to allow luggage to be stowed under the panels when the roof is down. Capacity drops, though, to just 230 litres.

The Gran Coupe, on the other hand, is the most practical car in the entire 3 and 4 Series line-up outside of the 3 Series Touring wagon. With a large, flat load area, and a hatch-like tailgate, the Gran Coupe can swallow 480 litres of gear with the seats up and an impressive 1300 litres with the seats lowered.

Face-level rear vents, more head and backseat legroom – not to mention the fact you don't have to squeeze into the rear past the front seat – makes the Gran Coupe a most useful device, and it's little wonder it's the most popular variant of the three.

Here’s the other big shock relative to the price-tag of the Sealion 5: This is not a small car. Based on the price, you might have been thinking the vehicle would be a compact SUV. And you’d have been wrong. This is a proper mid-sized SUV with room for five and luggage and an overall length of 4.7 metres and change. And to put that into some kind of perspective, that’s just 30mm shorter than the Sealion 6 which costs about $9000 more at its starting point.

The wheelbase is long, too, and the 2712mm between the axles helps make the interior even more spacious. That means there’s lots of stretching room in the front, but also that a grown adult can comfortably sit in the back seat behind another grown adult at the wheel and still have enough room in every direction. The window sills are commendably low in the rear seat, too, ensuring even littlies can see out.

The biggest problem in the back is that the seat cushion is a bit flat, but, like the front chairs, it’s still pretty plush.

With all five seats in place, the Sealion 5 boasts 463 litres of luggage space and the cargo area is well done with storage pockets at each side, a light and an under-floor tray designed to transport charging cables and a tyre repair kit. Yep, that’s right, there’s no spare tyre of any sort here. No surprise, really.

Fold the rear seat down and you’re suddenly looking at 1410 litres of cargo space and your SUV is now a panel van.

As well as the dual-zone climate control, the Sealion 5 also offers a single USB -C and a USB-A charging port in the front and rear compartments.

The Sealion 5 also offers a V2L (Vehicle to Load) function, meaning it can power camping or on-site work equipment and even act as your home’s battery.

The plug-in hybrid in question is the BYD Sealion 5. It has a claimed EV-only range of better than 100km, relatively quick charging, a decent sized battery, adequate performance, enough interior space for a family, good safety and lots of equipment. Oh, and it costs just $33,990, before on-road costs, in its entry-level Essential form. Incoming!

Equipment-wise, that sub-34K sticker gets you a 10.1-inch central info-screen, an 8.8-inch driver display, digital radio, a six-speaker stereo, wireless connectivity for Android Auto and Apple CarPlay and dual-zone climate control.

Throw another four grand on the table and you move up to the Premium version which adds plenty of kit for the $37,990 ask. That includes a panoramic sunroof, automatic tailgate, roof rails, heated and electrically folding mirrors, one-touch power windows, a six-way powered drivers seat and four-way powered co-pilot’s chair, a heated and ventilated driver’s seat and wireless charging.

The step up from Essential to Premium also includes a battery upgrade, and we’ll cover that off in the Under the Bonnet section below.

There are two new petrol engines, two new badges and prices cuts of up to $10,000 right across the board for the line-up, along with additional standard equipment that improves the value equation even further.

The line kicks off with the 420, which can be had in either diesel or petrol guise. The 420i gains BMW's new B48 2.0-litre four-cylinder turbo petrol engine, which gains 5kW over the old motor to produce 135kW and 270Nm.

It also benefits from slightly improved fuel economy, with a drop of 0.3 litres per 100km for the Coupe and 0.5 for the Gran Coupe to 5.8L/100km, and a fall of 0.2L for the Convertible to 6.2L/100km.

The 420d retains its 140kW, 400Nm 2.0-litre four-cylinder turbo diesel engine, which returns 4.3L/100km in the fixed roof cars and 4.7L/100km for the Convertible.

The 430i – formerly known as the 428i – also receives the new 2.0-litre petrol engine, albeit in a 185kW/350Nm tune. Its fuel economy drops a healthy 0.6L for the Coupe and Gran Coupe and 0.4L for the Convertible, posting figures of 5.8 and 6.3L/100km respectively.

The top-spec 435i has been transformed into the 440i with the addition of BMW's new Twinpower 3.0-litre straight six petrol motor. Its output jumps 15kW to 240kW and by 50Nm to 450Nm, and its consumption falls by more than half a litre to 6.8 litres per 100km for the closed-roof pair and 7.2L/100km for the Convertible.

All cars come standard with a 'traditional' ZF eight-speed torque converter automatic transmission with steering wheel paddles as standard fitment, while a six-speed manual gearbox is a no-cost option across the line.

Both variants of the Sealion 5 have the same driveline – mostly. They each use a 1.5-litre petrol engine teamed with a single electric motor, both driving the front wheels. Unlike the bigger Sealions, there’s no all-wheel drive version. Power peaks at 156kW and torque at 300Nm.

Why a non-turbocharged engine? BYD tells us the non-turbo engine helps keep cost out of the vehicle and, since the engine really only runs to power the electric motor and charge the batteries, it does so at a relatively constant engine speed, negating the need for a wide spread of petrol power.

The only major difference is that the Essential version has a 12.9kWh battery-pack, while the Premium gets a bigger, 18.3kWh pack for longer range, but precisely the same output and, therefore, performance.

A single-speed transmission is part of the BYD driveline package, also made possible by the fact that the vast majority of the driving of wheels is done by the electric motor.

Our brief test loop on a rainy, blustery Melbourne winter's day in all three model types (but no diesel) netted varying fuel consumption readings across the line; we recorded 8.4L/100km in a 420i sedan against a claimed figure of 5.8, 9.8L/100km for the 430i Gran Coupe against a claimed figure of 5.8L/100km, and 8.4L/100km against the 440i Gran Coupe's 6.8L/100km.

The Premium’s bigger battery claims to up the official NEDC range from the Essential’s 71km to 100km. BYD reckons with the 52-litre fuel tank brimmed and the car operating at its claimed 1.2 litres per 100km efficiency, the range of either version is just on 1000km. In the real world, that’s likely to be closer to 800km (especially with some highway running thrown in) but it’s still one heck of a solution to range anxiety.

There’s no DC charging function for the Sealion 5, so forget about commercial fast chargers. But on a 3.3kW AC power outlet, the maker claims the Essential can reach full charge in under four hours, while the Premium’s bigger battery will take under six hours to fully charge. A Type 1 charge cable is included.

BMW introduced a raft of tweaks to the 3 Series platform late last year, which have translated over to the 4 Series. The key addition across the line is BMW's two-stage adaptive dampers that feature a Sport and a Comfort circuit, fitted as part of the M Sport pack that comes standard on the 430 and 440, and is a $2600 option on the 420.

Larger 19-inch rims are fitted to the 430i and 440i cars, while the 420 gets 18s out of the box. It's possible to fit 18s on the more expensive cars, as part of the no-cost Luxury option pack that supplants the standard M Sport pack.

While our test was brief and held in less than ideal road conditions, the large-wheeled 4 Series really didn't enamour themselves to this author. There's a distinct lack of communication from the tyres and chassis through the steering wheel and your backside, while the combination of firm Sport shocks and large 19-inch wheels with narrow-section tyres made for an uncomfortable ride over country roads.

Sampling a 420i with the Luxury 18-inch rims, however, improved things immensely, with much better feedback and comfort that didn't come at the expense of handling.

One of BMW's strong points should be its steering, given all the 3 and 4 Series cars are still rear-wheel-drive… but it's not, unfortunately. The electrically assisted set up is far from perfectly calibrated, feeling too dull and digital underhand, no matter what the setting.

The pick of the bunch performance wise is – logically – the six-cylinder 440i. The turbo powerplant is potent from right down the rev range, with a muted yet still pleasing engine note permeating the cabin. The self-shifting mode on the eight-speed auto does a good job of keeping up as well.

The updated 2.0-litre four is a sprightly performer, too.

You don’t have to drive very far to realise that the local input into the Sealion 5’s suspension and steering have been worth the effort. BYD Australia has a local engineering team on call these days, and it shows here.

Actually, the steering is not the highlight; it has some weight but not a whole lot of feel, or, indeed, feedback for the driver. The ride and handling combination is what stars. Obviously well-damped, the suspension allows for a ride that is both complaint and quiet, without causing the car to wallow around like some jacked-up designs can with their higher centre of gravity.

In fact, the BYD is athletic to the point where keener drivers will find it an entertaining drive; hardly something that can be said for the majority of medium SUVs.

Performance is strong without being overwhelming and even though the Sealion 5 has that signature electric-drive feeling of effortlessness, the accelerator pedal has been calibrated to avoid the neck-snapping surge of grunt off the line. As such, it emerges with a fairly flat acceleration curve, and no hint that the petrol motor is cutting in or out.

Until, that is, you bury the throttle all the way at which point the petrol engine takes a few second to join in. And when it does, it’s pretty vocal – shrill, almost – as it catches up with the rest of the car and starts directly driving the wheels. To be fair, though, this is not going to be a common occurrence in everyday life thanks to the flexibility of the petrol-electric system for 99 per cent of circumstances.

On the move, the cabin is perhaps most notable for its soft, plush seats that are a nice change from the church pews of some manufacturers. And although the driving position is about right, taller drivers might prefer a steering column that extends out another few millimetres.

The driver display screen is another source of annoyance. It’s pretty small and contains lots and lots of information, to the point where the typeface is too small to be read on the run by anybody who relies on reading glasses.

Passive safety in the Sealion 5 starts with no fewer than seven airbags including full-length side-curtain bags. 

There’s also a front-centre airbag, something we’d like to see in more cars, particularly at this price-point. Child restraint points in the rear seat are the ISOFIX type.

The BYD gets pretty much the full suite of driver aids, including autonomous emergency braking, blind-spot monitoring, rear-cross traffic alert with active assistance, stability control, active cruise-control, traffic-sign recognition, front and rear collision warning and tyre pressure monitoring.

The Sealion 5 also incorporates a driver-attention monitor which seems better calibrated than some earlier efforts from some of the Chinese carmakers. Also improved in calibration terms is the lane-keeping assistance which is still too violent for our tastes, but more subtle than some of the competition’s systems. But while the savagery of this system has been toned down, it appears to have been at the expense of sensitivity and, time and time again, the cameras missed road markings that were faded or dirty.

The major safety benefit in paying more for the Premium variant is the addition of front parking sensors and a 360-degree camera instead of the Essential’s simple reversing camera.

The Sealion 5 has not been ANCAP tested as yet, although BYD says this is largely down to ANCAP’s scheduling rather than any hesitance on BYD’s part.

BMW offers a Service Inclusive program at the time of purchase, which for $1340 covers everything – including items like spark plugs, brake fluids and other fluids - for five years or 80,000 km scheduled. The cars are also covered by a three-year free roadside servicing program, in addition to BMW's two year, unlimited kilometre warranty.

Like other BYDs, the Sealion 5 comes with a six-year/150,000km warranty. Some of the competition have unlimited kilometre warranties, but to be honest, 150,000km in six years is going to be beyond the need and aspirations of most owners.

The EV battery is covered by an eight-year/160,000km warranty, and let’s not forget, BYD was a battery manufacturer before it started making whole cars. Certainly, the company is very bullish about the quality and safety of its 'Blade' battery technology, claiming it easily passes the technically-daunting 'nail-puncture' test.

BYD plans to have capped-price servicing for the Sealion 5, but no pricing announcements have been made yet.

Servicing also falls into line with other BYD models, so that means 12 months or 20,000km intervals.