Denza B8 vs BMW 428i

What's the difference?

The Denza B8 is an incredibly luxurious car that has a lot going for it, including three rows of seating, a 3.5-tonne braked towing capacity and an eye-popping price tag, but it's held back by its overall heft and cumbersome ride.

If you don’t absolutely need the third row of seating, the smaller B5 is arguably the better pick and while it’s also not perfect, it’s a very compelling package and you’ll be saving thousands of dollars in the process.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

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.

There’s no way around it, the Denza B8 is a big car. It’s almost 5.2 metres long which makes it larger than a LandCruiser 300 Series and more in line with the likes of the Land Rover Defender 130.

It looks quite boxy and tough on the outside, though it doesn’t have any features that define it specifically as a Denza beyond the inconspicuous badging. There are many angles that are reminiscent of the aforementioned Defender.

The body lines look crisper than the smaller B5, as does the semi closed-off grille and LED light script that connect the big LED headlights.

Unlike the B5, the tailgate-mounted spare wheel is much more prominent in the B8 and this therefore exaggerates its heft, not in a good way.

Inside, it’s luxurious and high-end with lots of visual appeal. I particularly like the amount of soft-touch finishes around the cabin and the overall lack of glossy piano black.

While luxurious, there’s also a rugged edge to the interior. This is most present in the large grab handles which you do need to use when getting in and out.

The amount of physical buttons and switches inside is a nice touch as you don’t need to relate on the touchscreen all the time. The fact the gear shift lever rises up when you turn on the car also adds to the special, luxurious feel.

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.

Hopping into the B8 you need to acquaint yourself with how the flush door handles operate. Generally they pop open when you unlock the car but sometimes they can be a little delayed.

Also inside the car there are electronic door release buttons which are nowhere near as intuitive as regular door pull handles. Sure you’d likely get used to this over time but you’ll need to explain it to new passengers all the time.

The seats in Chinese cars usually look nice but aren’t that comfortable or supportive for long-distance journeys. The B8’s are the opposite, offering great support and almost limitless adjustability. Adding to this is the standard heating, ventilation and massage functions.

Ahead of the driver is a leather-wrapped steering wheel which feels nice and has plenty of physical buttons with a tactile click when pressed.

Behind this, the digital instrument cluster is clear and high-resolution and offers a number of different layouts and informative pages you can cycle through. This allows you to customise the display.

In the centre of the dashboard is the mammoth 17.3-inch touchscreen multimedia system which is the largest central screen I have seen in a car to date. It’s a big screen for a big car and Apple CarPlay satisfyingly takes up the entire screen.

Thankfully, the screen is snappy and has a native user interface that is easy to navigate around without getting lost. I particularly like the swipe-down control centre menu that allows you to change key settings without diving into sub-menus.

My only hassle with the screen is I struggle to reach the far left-hand side due to its overall size. Perhaps a trackpad would solve this.

As I noted previously, the amount of physical switchgear around the cabin makes adjusting key functions easy. Examples include physical buttons to change the drive mode, activate the surround-view camera, adjust the suspension position and switch between EV and hybrid driving.

In terms of storage up front there are two non-ventilated 50W wireless phone chargers, two cupholders with adjustable depths, a shallow storage section under the centre console, plus a fridge/hotbox under the centre armrest.

Moving to the second row and the luxury continues. The seven-seat model features a three-seat bench that three people can easily fit across as the floor is flat, whereas the six-seat model gets uber-plush captain’s chairs.

Regardless of variant, there’s plenty of room in the second row, even for adults.

Second-row amenities include a small screen on the back of the centre console box that allows you to change the climate control and change the seat heating/ventilation, among other functions.

There’s also a button that opens the fridge/coolbox so the second-row passengers can access it. This is a nifty touch though you’d want to make sure small fingers don’t get caught as the anti-pinch function isn’t the strongest.

A feature that’s unique to the six-seat version is a massaging function on the second-row captain’s chairs. This is a very cool touch that no other SUV at this price point offers.

Accessing the third row in the six-seat version is rather easy as you only need to walk down between the captain’s chairs. It’s also simple enough in the seven-seat version as long as you access it from the kerb side.

Third-row space is decent for adults, but this shouldn’t be surprising as the B8 is such a hulking vehicle. The backrests also recline allowing for extra comfort. Amenities include air vents in the headliner, USB-C ports and scattered storage. It’s enough for seats that will likely only get occasional use.

Around the back the B8 has a side-hinged tailgate which is a little problematic as you need to allow space for it to open up in parking spaces. This is hard when the car is already 5.2m long…

With all three rows upright there is 147L of boot space, which is fine, but this expands to a much more usable 920L with the third row folded.

The boot space is square and usable, though there is a large load lip which is body-coloured and would easily get scratched if you drop something on it. Not the best in a family-oriented vehicle.

Boot-related amenities include buttons to electronically fold the second and third row seats and lower the suspension to make things easier to load into the boot, a 12V socket, scattered hooks, as well as a small underfloor section to store the changing cables.

Although it stands out like a sore thumb, it’s great to have a full-size spare wheel on the back of the tailgate. This is very helpful in the unlikely and unfortunate event you get a puncture.

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.

Entry into the 4 Series world now stands at $68,900 plus on-roads for the petrol 420i Coupe and Gran Coupe, and tops out at almost $118,000 for the 440i Convertible.

Both the 420i and 420d have been boosted by the addition of adaptive M dampers, a heads-up display, powered folding rear-view mirrors, lane-change warning, driving assistant and BMW's surround view camera with top and side views.

BMW claims the extra kit is worth just over $8000. Leather seats, sat nav, BMW's ConnectedDrive Emergency call system, bi-Xenon headlights and reversing camera are also featured. An eight-speed automatic transmission is offered as stock, but a six-speed manual can be optioned at no cost.

The diesel version costs an additional $2200 over the petrol powerplant.

Stepping into the 430i, the M Sport Package is offered as standard, with the Luxury line, which includes a leather-trimmed dash, a no-cost option.

Additional standard equipment over the outgoing 428i includes 19-inch M rims, heads-up display, lane change warning, driving assistant and surround view camera. The 430i also gains electric lumbar support for driver and front passenger seats and a nine-speaker stereo system over the base 420i.

Finally, the range-topping 440i scores a heads-up display, lane change warning, driving assistant, surround view camera, adaptive LED headlights, leather dash, front seat heating, high beam assist, active cruise control with stop and go function and parking assistant over the outgoing 435i.

Over the 430i, the 440i also gets variable sport steering, a Harman/Kardon surround sound system with 16 speakers, a leather instrument panel (with M Sport Package), ConnectedDrive internet and concierge service, and air collar neck-warming ducts for the 440i Convertible.

Power comes from a plug-in hybrid set-up combining dual electric motors and a 2.0-litre turbo-petrol four-cylinder engine.

Total system outputs are a meaty 425kW and 760Nm. They need to be, as the B8 has a kerb weight of 3.3 tonnes. Despite this, Denza claims it can still do the 0-100km/h sprint in just 4.8 seconds.

Power is sent to all four wheels with a rear mechanical diff lock as standard across the line-up. A front diff lock is only offered on the six-seat version.

What’s most surprising about this big beast is it offers a segment-meeting 3500kg braked towing capacity. It also has up to 700kg of payload, depending on the variant.

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.

Feeding the dual electric motors is a 36.8kWh lithium iron phosphate (LFP) battery. Denza claims it allows for an electric range of 115km, according to NEDC testing.

The battery can also be used as a power source for appliances using vehicle-to-load (V2L) functionality at rates up to 6.6kW.

AC charging is offered at rates up to 11kW, whereas DC fast-charging is offered at rates up to 120kW.

Additionally, there’s a 91L fuel tank. Denza claims this allows the B8 to have a total range of 1040km (NEDC).

Fuel consumption depends on how often you charge the battery. Denza claims the B8 will use 2.0L/100km from 100 to 25 per cent battery charge and 9.9L/100km under 25 per cent battery charge, both according to NEDC testing. Regardless, this is better than all similarly sized petrol- or diesel-powered SUVs.

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.

Behind the wheel, the Denza B8 primarily acts as an electric vehicle (EV), meaning it’s largely quiet inside the cabin when driving around normally.

Once the battery charge gets down lower, the petrol engine typically switches on to top up the battery. It largely acts as a generator and a lot of the time you can’t tell whether it’s on or off.

You’ll likely only notice it if you floor the accelerator or go up a steeper hill. Even then the engine largely stays quiet and in the background.

When the battery charge gets down low enough and you gun it, the petrol engine can directly power the front wheels. This is rare, though, because the car leaves at least 25 per cent battery charge in reserve.

With 425kW and 760Nm thanks to the dual electric motors and 2.0-litre turbo-petrol engine, the B8 is far from slow. In fact, for a 3.3-tonne beast it absolutely hauls thanks to the instantaneous torque the electric motors provide.

However in the standard drive mode there is a noticeable input lag from when you push the accelerator pedal hard and when the car starts accelerating. This is reduced in the 'Sport' drive mode.

Although the B8 may produce lots of power and torque, it feels its weight. When you accelerate hard it pitches back dramatically, much like the Jeep Grand Cherokee. It’s much more pronounced than in the smaller B5, but still smile-inducing.

As standard, the B8 line-up gets an adaptive hydraulic suspension system that is claimed to be able to self-level the car. Despite this, the B8 gets a considerable amount of body roll regardless of which drive mode you select.

Many Chinese cars have floaty, comfort-oriented suspension tunes over firmer and a more dynamic-feeling ride, and the B8 is no exception. It feels like a 3300kg+ SUV.

The kicker is, like many body-on-frame vehicles, the ride gets busy on harsher roads with more frequent bumps. As a passenger you get jostled about in the cabin.

The steering tries to disguise the overall heft of this SUV but as a result it can feel overly assisted and vague at certain points. Depending on the drive it either artificially adds or reduces resistance.

Unlike the related BYD Shark 6, the B8 gets diff locks and a low-range mode which uses a clutch pack on the rear electric motor to allow for more controlled, low-speed crawling.

The adaptive hydraulic suspension allows the car to be lowered down or lifted up. In its highest mode there is a 890mm maximum wading depth.

Interestingly, compared to the smaller B5, the B8 feels more sorted off the beaten path. Its added heft helps round off bumps more easily, plus there’s added momentum behind it.

Lastly, in terms of noise, vibration and harshness (NVH), the B8 is a very quiet car to drive. As I mentioned above, the electric-first nature automatically makes this a quiet car.

Surprisingly, given the B8 is a huge 3.3-tonne box on wheels, there is very little road and wind noise. It seems Denza has put a big emphasis on sound insulation.

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.

 six airbags, lane departure warning, pre-collision safety pack, parking sensors, active cruise control with collision warning, AEB and pedestrian warning, along with reversing camera and surround-view cameras across the line.

The Denza B8 is covered by a six-year, 150,000km warranty, whereas the battery pack is covered by an eight-year, 160,000km warranty. There’s also three years of roadside assistance.

This isn’t a standout warranty in the mainstream market, though compared to premium marques it’s a notable step up.

Logbook servicing is required every 12 months or 20,000km, whichever comes first.

The first five years' of servicing totals $3762, which averages out to just over $750 per service. This is just a tad more than the smaller B5, but it’s much cheaper than premium rivals.

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.