BMW 4 Series vs BMW 6 Series

What's the difference?

The BMW M440i xDrive Gran Coupe manages to combine sleek design with a fun-to-drive personality and surprising practicality. It’s a rapid premium, four-door, five-seater offering extra flair, and in this part of the market, good value. But more than anything else it’s got a cracking in-line six under the bonnet.

This isn't a car for everyone's tastes, but if you fit in to the buyer group that just doesn't really know what they want in a luxury car, it could be the perfect fit for your family. The 6 Series GT is a practical large prestige car, albeit one that will likely find very few buyers.

So, how does this four-door 4 Series differ from a four-door 3 Series? The answer is as plain as the nose on this car’s face.

BMW’s head of design, Adrian van Hooydonk, has been expanding the brand’s signature ‘kidney grille’ in every conceivable direction, and this is the much talked about interpretation adorning all 4 Series models (petrol, hybrid and electric) as well as the M3 sedan.

The new Gran Coupe is longer, wider, and taller than the outgoing model, and the track is broader, front and rear. The wheelbase has also been extended, now a whole 5.0mm longer than the 3 Series.

The DRLs and headlight main beams are LED with laser high beams, immense gills square up the edges of the front clip, while a vent and the strake attached to it stand the car apart. Plus, of course, the doors are frameless. 

One niggle, though. I’m not in love with the slender door handles. It’s hard to get a good grip on them, especially in the wet. 

Standard 19-inch alloy rims are shod with Pirelli P Zero rubber 245/40 fr / 255/40 rr), the roofline slopes distinctly towards the rear, a lip spoiler on the trailing edge of the tailgate is classic BMW, darkened LED tail-lights wrap around the rear corner, and a diffuser-type panel is flanked by large exhaust apertures.

Our car’s ‘Aventurine Red’ finish is a $3850 option, but to my eyes anyway it looks superb.

Exterior trim including the grille frame, front air intake inserts, mirror upper housing, model designation badges, and tailpipe are finished in ‘Cerium Grey’, which I reckon 99.9 per cent of people will see as black. 

The interior will be familiar territory for any current BMW owner, the 12.3-inch digital instrument screen sitting in a compact, hooded binnacle, and partnering with a 10.25-inch multimedia display standing proud of the dash above the broad centre stack. 

The seats are trimmed in top-shelf leather with blue contrast stitching, plus the grippy sports wheel is also wrapped in genuine hide.

BMW calls the finish on the main buttons and controls ‘Galvanic’ which translates to a slick silver metallic look and feel. Configurable ambient interior lighting is a nice touch, and the broad console enhances the driver-focused feel, with a sprinkling of carbon-fibre around the centre console and dash lifting the sense of occasion.

Overall, the interior feels clean and classy with an obvious attention to detail.  

There is no denying the 6 Series GT looks better than the old 5 Series GT. It isn't as frumpy, it looks more sporty, and to me it appears to have grown into its identity with more conviction than its predecessor.

That said, I don't necessarily like the look very much - it's a bit like a BMW X6 that has been rounded off a little and lowered down substantially. But I can appreciate some of the finer design aesthetics that it offers up: the frameless windows are a nice touch, and the swooping roofline looks smoother than a duck's back.

Other things like the active grille shutters and the air breathers ahead of the front doors are nice functional touches, and to my eye it lives up to BMW's hope of it looking "smooth but muscular". You can get the 630i with either the M Sport package, like you see here, or the more sedate Luxury Line, which is, well, more luxurious looking.

The M Sport styling and equipment package you see in the images here - with M aero kit and 19-inch wheels (ours had been upgraded to optional 20s) - help out with the athletic look of this very big vehicle.

It's huge in fact. The length of the 630i is 5091mm long, it measures 1902mm wide and sits at 1538mm tall, with a lengthy 3070mm wheelbase.

All that equates to a lot of room in the cabin, and what a sumptuous and delightful place it is to be - leather, wood and plush finishes abound.

At close to 4.8m long the 4 Series Gran Coupe is a sizeable machine. Up front, the feeling is airy and comfortable, and the rear is surprisingly spacious, especially in light of the car's sloping roofline.

At 183cm I have to fold myself tightly to fit under the low roof, but once inside I have enough room to sit behind the driver’s seat set for my position with more than enough legroom and adequate headroom. Put three full-size adults across the back row, though, and there will be breathing difficulties.

Kids will be fine, however, and individual vents with adjustable temp in the rear was a big plus during a particularly hot test week.

For storage there are generous door bins in the front with room for large bottles, a decent glove box, dual cupholders in the centre console, a reasonable lidded bin (which doubles as a centre armrest), and the wireless device charging bay (forward of the gearshift) makes a handy oddments space when not in use.

In the rear, again the doors feature pockets with room for (medium-size) bottles, there’s a fold down centre armrest with two cupholders, but thanks to the one-piece shells on our test car’s optional M Sport front seats there are no map pockets.

Power and connectivity runs to a USB-A socket and a 12V outlet in the front centre console, as well a USB-C port in the front storage bin, a pair of USB-Cs in the rear, and a 12V outlet in the boot.

Speaking of which, lift the tailgate and with the rear seat upright we were able to fit all three of our suitcases or the beefy CarsGuide pram into the healthy 470-litre (VDA) boot space.

Lower the 40/20/40 split-folding rear seat down and 1290 litres of volume is at your disposal. Plus there are handy bag hooks and tie-down anchors to help secure loose loads.

You can also tow a braked trailer up to 1.8 tonnes (750kg unbraked), but don’t bother looking for a spare of any description, a repair/inflator kit is your only option.

Now, I said before that this is a bit like an X6, but it has heaps better interior space than that SUV.

As soon as you slide into the driver's seat, you feel like your inside a large car. The cabin space is plentiful, and there's an abundance of storage on offer, too: there's a split-lid armrest between the seats, a pair of cupholders, a phone storage nook with wireless charging, and big door pockets with bottle holsters.

In the back you have access to door pockets, a flip-down armrest with cupholders (that middle part of the seat can fold down completely to allow storage of longer items), and there's excellent room on offer. How many seats in the BMW 6 Series GT? Five - like, five full-size seats.

Because the roofline doesn't rake as sharply as a four-door 'coupe', headroom is excellent for adults (even of the 183cm variety, like myself), and legroom and toe room are equally very good. This is bigger in the back than a 5 Series, but maybe not as plush as a 7 Series… so I guess it makes sense numerically for its nomenclature.

Of course you get climate control in the front (and in the rear if you option it), and the materials are excellent. The media screen is tablet-style, proudly displaying 10.25 inches of high-def real estate that is both touch-capacitive and controllable by way of the central rotary controller with touchpad. And get this - you can even use gestures to control certain elements like volume, swiping and changing tracks… but you have to option that.

The fully digital instrument display is bordered by a set of incomplete dial rings, which is just odd. BMW, back yourself - your buyers can handle just having a digital screen in front of them, particularly when it's as good as this one.

This grandiose hatchback's boot is commodious - with the back seats in place it has a huge 610 litres of cargo capacity, which extends to 1800L with the 40/20/40 seats folded down using the quick release levers in the boot area.

There is no spare wheel (the BMW range is fitted with run-flat tyres) but it does have a secondary hidden storage area under the boot floor for hiding items or stowing wet gear, bathers/swimmers or muddy clothes.

For context, the X6 has 580L seats up, 1525L seats down.

The BMW 6 Series Gran Turismo range starts off with the model tested here, the 630i. It has a list price of $123,500 before on-road costs - and that's whether you buy the M Sport Line or the Luxury Line.

That's quite a lot of money. And while it has a lot of equipment to help justify the cost, the smarter dollars will probably find their way to a more affordable 5 Series.

Standard gear in this spec includes adaptive air suspension with multiple drive modes, a colour head-up display, semi-autonomous parking, adaptive cruise control with steering assistance, auto high-beam LED headlights with LED daytime running lights, DAB+ digital radio, a 16-speaker harman/kardon sound system, a 12.3-inch driver information screen and a 10.25-inch media display with sat nav, Bluetooth and 'BMW ConnectedDrive' online services.

Hey, you even get a panoramic sunroof as standard! Plus there are things like an active rear spoiler, two USB ports and four 12-volt outlets, leather trim, heated front electric seats, electric steering wheel adjustment, keyless entry, push-button start, and an automatic boot.

It also comes loaded with active safety assistance functions - we'll get to that in the safety section below.

Things it's missing at this price point? Well, heated seats are an option, but bundled nicely into the 'Comfort Package' ($3000) which was fitted to our car. The pack includes heated seats front and rear, quad-zone climate control, electric sunblinds for the rear side windows, and electric seat back adjustment. Oh, and BMW continues to gouge consumers $623 for Apple CarPlay (which seemingly didn't work in our car).

The only other 6 Series GT model available is the 640i xDrive, which is again available with the choice of M Sport or Luxury body styling. It's also pretty exxy, with a list price of $148,900, but gets a more performance-focused drivetrain, as well as extra equipment: essentially the Comfort package, plus vented front seats, interior fragrance (eight options), memory settings for the front seats, 20-inch wheels and metallic paint.

Plus the 640i has Sport+ settings - it's probably the wrong car for those - and 'Integral Active Steering' to couple with the all-wheel drive system.

Under the bonnet is BMW’s (B58) all-alloy 3.0-litre twin-scroll turbo intercooled, in-line six-cylinder engine, driving all four wheels via an eight-speed automatic transmission and electronically controlled clutch pack, as well as an electronic limited-slip differential at the rear.

It features high-pressure direct-injection and BMW’s ‘Valvetronic’ system managing air flow to the intake side, to produce 285kW at a relatively high 5800-6500rpm. But the big punch is 500Nm of peak torque from just 1900rpm all the way to 5000rpm.

The M440i is also a mild-hybrid with a 48-volt starter motor-generator and supplementary battery able to give an 8.0kW kick at low engine speeds.

Under the bonnet of the 630i is a 2.0-litre four-cylinder turbocharged petrol engine, which produces 190kW of power (at 6500rpm) and 400Nm of torque (from 1550-4400rpm). It uses an eight-speed automatic transmission, and is rear-wheel drive.

That may not seem a lot considering the size of this machine, but consider that some of the steamiest four-cylinder hot hatches have nearly the same outputs, and you realise this engine offers up a far-from slouched approach to propulsion.

The 640i xDrive has a 3.0-litre six-cylinder turbocharged engine with 250kW of power and 450Nm of torque. It gets the same eight-speed auto, but as the xDrive naming indicates, it's all-wheel drive.

But this is the one you'd prefer if you want to hit highway speed in a hurry - the 0-100km/h claim is 5.3 seconds, where the 630i takes a full second longer (6.3sec) according to the company.

BMW’s official fuel economy figure for the M440i xDrive Gran Coupe, on the ADR 81/02 - urban, extra-urban cycle, is 8.2L/100km, the 3.0-litre turbo six-cylinder emitting 187g/km of C02 in the process.

Stop/start is standard, and we saw an average of 11.1L/100km over city, B-road and freeway running during a week with the car.

With the 59-litre tank brimmed (with minimum 95RON premium unleaded) that real-world test number translates to a range of around 530km.  

BMW claims fuel use of 7.0 litres per 100 kilometres, and you'll need to use 95RON premium unleaded when you fill up.

On my trip with the car, I saw about 9.0L/100km across mostly high-speed driving - some freeway, some highway, some country back road touring, and quite a bit of corners and city stuff thrown in as well. I think that's pretty respectable.

What wasn't so great was the lack of premium fuel in some of the 'away from civilisation' places on my route home. Keep that in mind if planning your own GT long-distance cruise.

BMW says the M440i xDrive Gran Coupe will accelerate from 0-100km/h in 4.7sec, and I reckon the threshold for a properly quick car is sub-five seconds.

The 3.0-litre turbo six develops its peak power of 285kW between a relatively lofty 5800-6500rpm, but the big number is a solid 500Nm punch of pulling power delivered between 1900-5000rpm.

Squeeze the throttle pedal pretty much anywhere in the rev range and the response is glorious. Rapid acceleration accompanied by raucous engine noise and rorty exhaust note (albeit with some synthetic support). Various pops and bangs in the Sport settings add extra entertainment.. 

The eight-speed auto gets some electric support from the mild-hybrid system to fill the torque gap on up shifts, and the result is a conventional torque-converter transmission that behaves like a dual-clutch.

Shifts are seamless in general driving, and satisfyingly quick in a more aggressive mode, the wheel-mounted paddles dialing up the fun in manual changes. 

Suspension is double wishbone front and multi-link rear with the standard ‘Adaptive M Suspension’ built around an adaptive damper set-up.

The change between the ‘Comfort’ setting to the ‘Sport’ or ‘Sport+’ calibration is close to instant and makes a discernible difference, especially in terms of ride comfort.

I found the best ‘Individual Sport’ arrangement to be damping in Comfort, with the steering engine and transmission in Sport. The car flows so beautifully through corners with urgent response from the powertrain.

By all means dial up the suspension if you’re having a real crack, but the car feels superbly balanced, stable and predictable in Comfort (front to rear weight distribution is 50:50).

The electrically-assisted variable-ratio steering is nicely weighted with good road feel, and the grippy sports steering wheel is a nice point of contact.

The xDrive AWD system’s default setting is rear-biased, although it will push most of the drive forward when required. But the RWD feel is unmistakable. 

The M440i weighs in at around 1.9 tonnes but feels lighter and more nimble than that figure would typically indicate.  

A standard electronically-controlled M Sport limited-slip differential puts the power down confidently. I have a favourite LSD test corner on my regular evaluation drive, a sharply twisting and rising left-hander.

Rolling into it in a low gear before planting the throttle mid-corner, the car simply hunkers down without a hint of fuss (or traction loss) as it rockets out the other side.

Optional M Sport front seats ($2000) provide comfort and firm location in equal measure and in terms of ergonomics BMW knows how to focus on the driver and set-up an efficient environment. Key controls are perfectly positioned and simple to operate.

I have an issue with the ‘Lane Departure Warning’ function, however, which is too quick to intervene and overly intrusive when it does so. I turned the ‘Steering Intervention’ function off. You can dial down steering wheel vibration warnings, too.

The standard M Sport brakes feature big vented rotors front and rear, with fixed four-piston front calipers doing the bulk of the work. They’re strong but don’t bite or release too aggressively. It’s easy to grease in a smooth application. 

I'll put this out there - if you like to drive, there are BMW models for less than this one that will put a much bigger smile on your face. Like, a 440i Gran Coupe, or even just a 330i sedan…

But if you're in BMW's target market - that being older executive buyers who want space and luxury as a priority over thrills at the wheel, you could do a lot worse.

That's because the 6 Series GT lopes along the highway without fuss - the engine easily coping with the demands of overtaking moves, the adjustable drive modes allowing a light steering and wafting suspension feel to wile away the kilometres.

There are 'Comfort' and 'Comfort Plus' modes, but the latter is a bit too spongy and can be boaty feeling. The Comfort setting is made for the highway.

It is actually pretty agile for its dimensions.

If you decide to deviate from the straight sections, you'll be able to explore a little bit of dynamic range, especially when you dial up the 'Sport' mode, which changes the damper settings, steering weight, throttle and transmission response, and even the digital dials in front of the driver to a more aggressive look.

Our car had the 'Integral Active Steering' setting, which is a variable ratio steering system that includes rear steering - that essentially helps make is more turnable in corners at highway speed, and easier to park at lower speeds. It's difficult to say whether the assistance is excellent or not short of driving a car without the tech, but to this tester it was hard to hide the size and weight (1835kg kerb weight) of the vehicle.

That isn't to say it's clumsy or lumbering - it is actually pretty agile for its dimensions, though it makes a lot more sense on long drives and coastal cruises than it does in the narrow and twisty alpine roads of the Snowy Mountains Highway that I tested it on.

There's good grip from the tyres, and strong response from the powertrain - but if it were my money, and I had to have a 6 Series for whatever reason, I'd be looking towards the 640i model, which has a thumping six-cylinder with 250kW/450Nm - certainly an engine that would be more at home in this car. Plus that model comes with AWD.

The BMW 6 Series GT range has a five-star Euro NCAP crash test score based on 2017 testing, but it hasn't been scored by ANCAP.

There's the usual array of airbags - dual front, front side, full-length curtain and driver's knee airbags are included, plus parking sensors all around, and heaps of safety tech including the 'Driving Assistant Plus' package with lane departure warning and lane keeping assist, forward collision warning, auto emergency braking (AEB) front and rear, blind-spot monitoring and rear cross-traffic alert, and adaptive cruise control with stop and go.

That's all great stuff, and so is the 360-degree camera system with adaptive display - so, if you're reversing and you turn the wheel to one side, the image on screen will move, too. It'll also go between a birds-eye view and a backing-up perspective, and that can take some getting used to.

What was less convincing in terms of the user experience was the rear auto braking, which seemed to be scared of the car's own shadow. On multiple occasions the car jammed on the brakes when reversing out of driveways on to empty streets - be it in the normal height, or the raised height setting.

The 6 Series GT has dual ISOFIX anchor points and three top-tether points are there and ready for baby seats or child seats.

The M440i Gran Coupe is covered by BMW’s three-year/unlimited km warranty (including paintwork), as well as 12-year/unlimited km anti-corrosion (perforation) cover. 

That’s off the premium market pace now with Genesis, Jaguar, and Mercedes-Benz at five years/unlimited km and Lexus set to join them from January 1st, 2022. 

That said, roadside assistance is provided for the duration of the main warranty, but it’s worth noting “rattles and squeaks” are only covered for one year.

Service is condition-based, the car telling you when maintenance is required, and a range of service packages are available. The basic plan covering a 4 Series for five years/80,000km comes in at $1750. 

BMW runs a condition-based servicing plan, which means the car will tell you when it needs servicing. But you can rest assured it won't (theoretically) cost you much, with the brand's 'Service Inclusive' pack. It covers you for basic maintenance as and when required for five years/80,000km. According to BMW, that includes "annual vehicle checks, oil changes, all filters, spark plugs and labour costs for the duration of the package".

BMW offers a three-year/unlimited kilometre warranty plan, and you get the same cover for roadside assistance.