It’s easy to recognise the BMW 4 Series Coupe as a two-door 3 Series by another name, but more difficult to decipher which specification level in the range to buy.
A four-tier BMW 4 Series Coupe range is now on sale locally, including the $69,500 420i, $71,500 420d, $80,500 428i and $108,500 435i, all of which represent a $15-20K premium over their respective four-door 3 Series cousins.
Compared with the outgoing 3 Series coupe, the 4 Series sits 60mm lower, delivering a centre of gravity of less than 500mm – the lowest of any BMW. Torsional rigidity increases by a claimed 60 per cent, length increases by 26mm and width by 43mm, while height falls by 16mm. Overhangs have been reduced by 13mm and 11mm, front to rear.
Despite the changes, kerb weights of between 1465kg (420d) and 1525kg (435i) either rise by just 45kg or remain unchanged respectively.
The 420d 2.0-litre turbo-diesel four-cylinder costs $2300 more than the turbo petrol model of the same capacity and cylinder count, and while 135kW of power is consistent between the two differently-fuelled engines, the diesel gets a heftier 380Nm of torque – up 110Nm.
As with all BMW 4 Series specification levels, an eight-speed ZF automatic transmission is standard, though a six-speed manual can be selected as a no-cost option. Compared with the same auto in the 3 Series, the 4 Series uniquely gets launch control (to improve performance) and a coasting mode that decouples engine from gearbox when rolling off the throttle (to improve economy).
Equipped with a tuned-up version of the entry-level petrol engine, the 428i produces 180kW of power and 350Nm of torque. The 428i claims a 5.8-second 0-100km/h, 1.5 seconds faster than both the entry-level diesel and petrol, and 6.4 litres per 100 kilometres, only 0.1L behind the 420i and 2L adrift of the 420d.
The 3.0-litre turbo petrol six-cylinder in the 435i range flagship (for now, until M4 arrives next year) buys 225kW and 400Nm and its 5.1-second 0-100km/h is 0.7 seconds faster than the 428i, but it costs a hefty $40K more.
Curiously, too, the 435i engine is 10kW/50Nm down on the M135i hatchback that costs an even more substantial $40K less.
Compared with the current 3 Series sedan, BMW claims the 4 Series Coupe has had its springs, dampers, axle kinematics and elastokinematics altered.
More specifically, there has been camber angle changes, wider front and rear tracks, and thanks to repositioned control arms, a roll centre reduced by 19mm. Extra body strengthening in the front end is claimed to enhance steering feel, while an additional strut connecting the front axle subframe to the body is said to create a stiffer connection between the two to provide sharper cornering.
Otherwise, though, BMW says the standard suspension on the 420i and 420d is based heavily on that of the 3 Series sedan, a set-up that deals poorly with country road bumps, lacking any semblance of comfort and control.
Those issues are largely solved in the 3 Series, though, by choosing the optional adaptive suspension that offers Comfort and Sport modes that respectively soften or harden the shock absorbers, and both of which dramatically improve the car’s behaviour.
Yet in the 4 Series range, BMW has chosen to make adaptive dampers standard only the 428i and 435i; in the 420i and 420d the adaptive suspension is a $2200 option.
So how do the changes translate with the entry-level BMW 4 Series compared with the 3 Series? In short, we don’t fully know.
Only a single 420d was provided with standard suspension at the local launch of the BMW 4 Series.
Experience first in the 420d suggests the diesel engine doesn’t suit the sportier 4 Series' personality, with a bit too much clatter and a slowness to rev. But a 420i wasn’t available to compare it with.
Nor did our test 420d ride well; there was initial impact harshness over small road imperfections, a constant restlessness over ostensibly smooth surfaces, and a decent amount of crashing over larger pot holes.
Why we can’t give a definitive verdict on this car is because BMW informed us after the event that they had been mistaken, and the test 420d did indeed have adaptive suspension. But it also admitted its run-flat tyres were over-inflated, which possibly explains why the 18-inch tyres absorbed the road surface as though they were filled with concrete.
Swapping into the 428i, and then the 435i, proved a revelation.
Standard across the range are 18s, fog lights, reversing camera with front and rear sensors, bi-xenon headlights, LED interior lights, auto lights and wipers, dual-zone climate control, Bluetooth phone and audio connectivity, and an 8.8-inch display with satellite navigation and 20Gb storage – partially justifying the circa-$15K premium over the equivalent four-door 3 Series sedan.
For a relatively small $8700 premium over the 420d, though, the 428i adds adaptive suspension, 19-inch alloys instead of 18s, dual exhausts, auto-dipping rear-view mirror, electric lumbar support and premium nine-speaker audio with internet functionality.
The biggest change and improvement, however, lies under the bonnet.
The 428i drivetrain is both outstanding and inspiring. Not only is it unmatched by anything from Mercedes-Benz or Audi on paper – a C250 coupe claims a 7.2-second 0-100km/h and 6.9L/100km; the A5 2.0 TFSI coupe 6.4sec/6.7L – but it is also one of the great four-cylinder engines in any production car.
Despite claiming the same outputs as the 328i with which it also shares its engine, the 428i has a meatier, louder engine note that is decidedly sportier. The eight-speed auto is both intuitive and shifts decisively, and many short gears makes this BMW feel even faster than its claims.
In the real world, the difference is just as scarce.
But armed with adaptive suspension, and even on 19-inch alloy wheels, the 428i and 435i both deliver the fluency and connectedness expected from a BMW sports coupe. They each ride well, in either Comfort or Sport mode, with a firmness that is still more appropriate in a 4 Series two-door than a 3 Series four-door.
In addition to an M Sport aerodynamics package, the 435i solely gets variable-ratio sport steering standard – a $520 option on the others – and it is the better system compared with the fixed-ratio electro-mechanical set-up on 420d and 428i.
Yet the standard steering also seems improved compared with that in the 3 Series, feeling more direct as lock is wound on and with a reduced vacant patch on centre. The increased sharpness of the variable-ratio system, though, means it is worth the extra on the regular models.
Both the 428i and 435i handle brilliantly.
On smooth roads, the front end can really be leant upon, and the 50:50 weight distribution and rear-wheel drive combine to make balancing the 4 Series as delightful as it is easy.
Add bumps – or cut a corner and mince a rippled kerb – and the adaptive suspension proves its worth, quelling the impact and remaining solid, planted and composed.
It feels even more dynamic than the already brilliant 3 Series.
Inside, there’s less change compared with the 3 Series.
It could be argued that given BMW made special mention of the renaming process reflecting the differences between new-generation sedan and coupe, the cabin materials and ergonomics are largely unchanged.
The plastics quality lags behind the much older Audi A5 coupe, for example. Meanwhile the steering wheel that obscures the trip computer display beneath the speedometer and tachometer, the lack of a ‘sync’ button on the dual-zone climate control, and a detatchable cupholder lid that needs to be awkwardly stored in the glovebox, all mean the 4 Series feels as un-premium ergonomically as the 3 Series.
On the upside, though, the larger dimensions of the 4 Series compared with the 3 Series coupe it replaces makes for handy boot space – 445 litres – and rear legroom (superior to A5 coupe). Charging extra for a 40:20:40 split-fold rear seat is mean, though (60:40 is standard).
Where the tested 420d is a three-star car, the 435i achieves four, and the 428i a peachy 4.5 stars. To think the latter model is almost as quick as the outgoing, similarly priced (5.2-second 0-100km/h) 135i coupe makes it all the more impressive, considering its extra size, class and dynamic ability.
A full test of a BMW 4 Series with standard suspension has now been requested.