BMW 428i vs BMW 535i

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.

Not all superheroes wear capes, and we're proud to report the 530e does its bit for green motoring without feeling the need to shout about it. And with no price or specification penalty, it's easier being green than ever before, and the pricing of this BMW really puts the cat amongst the canaries.

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.

Crucially, there's nothing weird about the way the 530e looks. While some green cars look like they've been designed by one of the kids from 3rd Rock from the Sun, the 530e looks much the same as the rest of the range, save a few tiny but telltale giveaways - like the e-drive badging outside, and what looks like a bonus fuel flap tucked in behind a front wheel that houses the whole plug-in bit.

And we really, really like it. It's elegant and statesman-like from every angle, and looked especially important in the deep-blue colour of our test vehicle. It's not over-designed, with body creases used sparingly, and the occasional glint of polished silver that rings the windows and the grille adds a final sense of shininess to an understated design. 

Inside, there's more going on than you might normally find in a BMW. The hugely complicated digital display screen now includes everything from battery charge, power usage to the usual assortment of speedometers and petrol readouts. 

It doesn't feel overdone or crazily festooned, but there's more at play here than in your usual BMW.

The dash is busy, too, with a wide screen emerging from a centre stack that also houses a CD player and a digital aircon setup, which in turn sits above a complex centre console from which you can alter driving settings, control the multimedia or cycle through electric modes. It doesn't feel overdone or crazily festooned, but there's more at play here than in your usual BMW.

Elsewhere inside, the seats are beautifully designed, with a quilted leather highlight through the middle, while the gloss-black strip that lines the dash hides a dual strip of ambient interior lights that also runs across all four doors.

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.

As the world's motoring tastes shrink faster than a lap-banded Clive Palmer, it's easy to forget the joys of the full-size sedan, but the space for passengers and luggage in the 5 Series will have you questioning your downsizing ways.

Upfront, there's plenty of room between front-seat riders, who will also share two smallish cup holders, along with room in each front door for bottles. There's also a dedicated wireless charge pad (which, because of its tight design, is crazy difficult to actually remove your phone from), but you'll also get two USB points and a power outlet that's hidden in the sizeable centre storage bin as standard fit.

Backseat riders get heaps of space, both in width and in leg room behind the front seats. And there's twin air-con temp controls and twin power outlets, too. But middle-seat passengers will be forced to sit with their legs on either side of the raised tunnel, which will definitely impact on comfort.

The boot's still sizeable, despite shrinking slightly to house the battery/fuel tank setup

Best to ditch the fifth passenger, then, and deploy the pull-down seat divider, which also houses two cup holders. Finally, there are three ISOFIX attachment points, one for each seat in the back.

The boot's still sizeable, despite shrinking slightly to house the battery/fuel tank setup (the tank has been moved further back to accomodate the batteries), and can be adjusted to be a flat load area if you'd like, offering up to 410 litres with the rear seats in place.

The 530e commands a 530i-equalling $108,900 price tag, which is genuinely impressive when you consider all the extra bits and pieces that go into make a plug-in hybrid. That money buys you a well-equipped car, and only those allergic to money need reach for the options list.

As standard, you'll find leather-wrapped - and heated in the front - sports seats, 19-inch alloy wheels and a 10.25-inch touchscreen that pairs with a really very good 16-speaker Haman Kardon stereo. Wireless Apple CarPlay is available, but it'll cost you an extra $500. To be honest, though, we didn't miss it.

You'll also find adaptive LED headlights, a huge head-up display (so big, in fact, that it impedes vision when climbing steep hills), dynamic dampers, an auto opening/closing boot and a self-parking system, along with BMW's suite of self-driving tech - but we'll come back to that under the Safety sub-heading.

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.

Drift around in pure EV mode and you'll be relying on the 530e's 83kW and 250Nm electric motor, which will provide what BMW refers to as "between 28 and 32 real-world kilometres".

Run out of range, or simply use too much throttle, and the 2.0-litre petrol engine comes into play, adding 135kW and 320Nm to the mix. All up, that's 185kW and 420Nm - respectable numbers by any measure, and enough to match the petrol-powered 530i's zero to 100km/h sprint of 6.2 seconds.

That power is fed through an eight-speed automatic transmission before being sent exclusively to the rear wheels, where it belongs.

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.

Like a Facebook relationship status, it's complicated. The 530e will sip a claimed combined 2.3 litres per hundred kilometres on the claimed/combined cycle, which is amazing for a car this size. Better still, it seems genuinely achievable - at the vehicle's launch, our own Richard Berry recorded a stunning 2.0 litres per hundred kilometres on a short test route.

But that's with a full load of battery charge on board. For our week with the 530e we were unable to actually plug it in (living in Sydney, I can't afford a garage), so once the initial battery charge had been used we were back to mostly petrol power. Unlike some other plug-in hybrids we've driven, we found it very difficult to recharge the battery to any meaningful level using regenerative braking, so once we were flat we stayed flat. If we had plugged it in, it would have been a two-hour recharge using a specialised wall unit, or about four hours using a normal plug.

As a result, though, our fuel use was closer to 7.0 litres per hundred kilometres after some considerable real-world testing.

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.

There's so much to like about the way the 530e sets about saving the world, and that's mostly because it doesn't shout about it, either to the driver or the outside world.

It's very much an underpants inside its pants superhero, which makes us like it even more. Set off in EV mode, and the 530e will drift silently away from the curb, burning battery power over fuel for as many as 30(ish) kilometres. But equally important, the shift from green to gas is largely imperceptible, with the petrol engine joining in willingly when you ask it to - usual via a prod of your right foot.

It is so effortlessly smooth that you need to really pay attention to notice the eight-speed 'box changing gears at city speeds, and it's commendably quiet, whichever drive mode you're in.

Downsides? Well, it doesn't feel quite as sharp as it's conventional-engined siblings. The batteries add around 230kg in weight, which never helps, and it all feels a little softer and a little less dynamic, even with Sport mode engaged. BMW assures us the adaptive suspension setup and tune is identical, but the 530e feels noticeably softer when you tackle a twisting back road. And that encourages you to use your right foot a little more, which in turn negates the whole electric thing in the first place.

One of the great joys of BMWs has always been their ability to transform from cosseting comfort to rear-drive rocket when you want them to, and you can't help but notice the 530e isn't quite up to that challenge. But if your intentions are mostly city- and freeway-based, then this plug-in BMW is almost indiscernible from its petrol-powered sibling.

You'll want for little here, with front, front-side and full curtain airbags joining parking sensors, a surround-view camera and a self-parking system.

You can also expect active cruise control, lane control assist with lane keep assist (so it will stay between the lane markings for you), AEB and cross-traffic warning. And all of that means that, technically, the 530e can drive for you. That is, of course, if you don't mind driving like a dick - in full-autonomous mode it will swerve from lane marking to lane marking like it's playing bumper bowling.

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 the rest of the 5 Series range, the 530e falls under BMW's three-year, unlimited-kilometre warranty. There are no set service intervals, either, with BMW using what it calls 'condition-based' servicing. In other words, the car will tell you when it requires a trip to the service centre.

The batteries are covered by a separate warranty covering six years or 100,000km.