BMW 528i vs Infiniti Q50

What's the difference?

Sleek and attractive in the city,  engaging on a country back road and with plenty of clever technology, the 5 Series sedan ticks all the right boxes as an executive express. If you can stomach the price hike, the six-cylinder 540i is our pick of the bunch.

The Q50 Red Sport is a premium sedan that's great value, with a cracker of an engine. While Infiniti has improved the ride and steering, it still feels to me that the engine is too powerful for the wheels and chassis to handle. But if you're looking for something of an untamed beast, this car could be for you. Just don't say we didn't warn you.

Hardly a revolution, the 5 Series has instead undergone a few nips and tucks. But if it ain't broke and all that. It might not be the most head-turning offering, but the 5 Series sedan remains sleek, powerful and understated, and it is undeniably handsome on the road.

Its 8mm wider, 28mm longer and 2mm taller than the car it replaces, but it's also around 95kg lighter, thanks to its aluminium doors and boot and a clever magnesium frame for the instrument panel that saved another two kilograms. There's some other clever design elements, too. The kidney grille has active air flaps that open when extra cooling is required, closing when it isn't, reducing drag and helping accleration.

Inside, the 5 Series offers a beautifully crafted yet joyously understated cabin, with quality materials joining modern technology in a seamless way.

The Q50 Red Sport looks cranky from front on, which I like in a car. Yes, the grille is simplistic and gaping, the nose is a bit bulbous, and sure, side on the car looks like a Lexus IS 350, but those rear haunches and the aggro body kit with its front splitter and boot lid spoiler make for an impressive looking four-door sedan.

The update brought restyled front and rear bumpers, those red brake calipers and the dark chrome 20-inch rims and new LED tail-lights.

Inside, the cabin is an asymmetrical paradise (or hell, if you're a bit OCD like me) full of sweeping lines, angles, as well as different textures and materials.

The red stitched quilted leather seats are an addition that came with the update, so is the new steering wheel and the ambient lighting.

The 'Sunstone Red' colour of our test car is also a new hue which looks a bit like Mazda's Soul Red. If red is not you, there are other colours – hope you like blue or white or black or grey because there's 'Iridium Blue', 'Midnight Black', 'Liquid Platinum', 'Graphite Shadow', 'Black Obsidian', 'Majestic White' and 'Pure White'.

The Q50 has similar dimensions to the IS 350: both are 1430mm tall, the Infiniti is 10mm wider at 1820mm,  120mm longer at 4800mm, and has a wheelbase that's 50mm longer at 2850mm.

This is a full-size sedan, and every seat feels spacious and airy. The sloping, slightly coupe-style roofline does cut into headroom in the back, but human-sized people will have little trouble, even sitting behind a tall driver.

Each trim offers two cupholders in the front, with another two housed in a pull-down divider that seperates the rear seat. And there's two ISOFIX attachment points, one in each window seat in the back. 

The 5 Series' boot opens to rival a surprisingly sizeable storage space, offering 530 litres with the 40:20:40 rear seats in place.

The Q50 Red Sport is a five-seat four-door sedan and is vastly more practical than its two-door Q60 Red Sport sister, in that I can actually sit in the back seat. The Q60's coupe styling looks amazing, but the sloping roofline means headroom is so severely limited that it reduces the rear seats to a place to throw your jacket.

True, I'm tall at 191cm, but in the Q50 Red Sport I can sit behind my driving position with legroom to spare and more than enough headroom.

Boot space is good at 500 litres, which is 20 litres more than the luggage capacity of the IS 350.

Storage throughout the cabin is good with two cup holders in the rear centre fold-down armrest, two more up front and bottle holders in all doors. A large centre console storage bin and another big storage area in front of the shifter are great for keeping junk under control and your valuables covered.

Maybe sit down for this next bit. The Q50 Red Sport lists for $79,900. Are you okay? Do you want a moment? Remember, though that only seems like a lot because it's not a Benz or a BMW. Truth is the value is pretty good – better than a German car of the equivalent size and grunt.

Look at the standard features list: 8.0-inch and 7.0-inch stacked touchscreens, the 16-speaker Bose 'Performance Series' stereo system, digital radio, road noise cancellation, sat nav, 360-degree camera, leather seats, power adjustable from sports seats, dual-zone climate control, proximity key, sunroof, auto wipers and adaptive LED headlights.

The 2017 update brought new standard features to the Red Sport including, red stitching on the seats and dash, quilted leather seats, new 19-inch alloy wheels and red brake calipers.

Don't forget that the bang-for-buck factor is strong with the Red Sport, too. In that nose is a twin-turbo V6 that makes almost as much grunt as the BMW M3 for about $100K less. Even the 340i, which Infiniti says is a Red Sport rival, is $10K more. Truth is though, the Lexus IS 350 is the real rival to the Q50 Red Sport.

The hunt for efficiency sees all but the most expensive 5 Series models equipped with four-cylinder engines, including the entry-level 520d, which is fitted with a 2.0-litre diesel unit that will produce 140kW at 4,000rpm and 400Nm from 1,750rpm. That's enough to push the cheapest 5 Series to 100km/h in a not particularly inspiring 7.5 seconds, topping out at 235km/h.

The cheapest petrol, the 530i, arrives with a turbocharged 2.0-litre engine good for 185kW at 5,200rpm and 350Nm from 1,450rpm. That will see you clip 100km/h in 6.2 seconds and push on to a limited top speed of 250km/h.

The turbocharged six-cylinder feels right at home in a car this size, with acceleration effortless and freeway overtaking manoeuvres an absolute breeze.

The 530d introduces the first six-cylinder engine, a 3.0-litre unit that will produce 195kW at 4,000rpm and an impressive 620Nm from 2,000rpm. That's enough to knock off the sprint in in 5.7 seconds and offers a top speed limited to 250km/h.

Finally, the top-spec petrol, the 540i, will produce 250kW at 5,500rpm and 450Nm from 1,380rpm from its 3.0-litre turbocharged straight-six engine. Those are healthy numbers, and enough to welcome 100km/h in a sprightly 5.1 seconds before topping out a limited 250km/h.

Every model is paired with an eight-speed torque converter automatic transmission.

Inside the Q50 Red Sport's nose is a 3.0-litre twin-turbo V6 petrol engine and it is a beautiful thing. To me this car is piece of technologically sophisticated jewellery that cradles a precious gem that pumps out 298kW/475Nm.

But I have my concerns... you can read about those in the driving section.

Shifting gears is a seven-speed automatic which delivers drive to the rear wheels.

BMW quotes a combined 4.3 litres per hundred kilometres from the 520d, which will also spit out 114g per kilometre of C02. The 530d lifts that number to 4.7 litres per hundred kilometres (which seems a small price to pay for all that extra torque), with C02 pegged at 124g per kilometre. Both diesels get a slightly smaller tank, at 66 litres.

The 530i will sip a claimed/combined 5.8 litres per hundred kilometres, with C02 emissions a claimed 132g per kilometre, while the big 540i requires 6.7 litres per hundred kilometres, with C02 pegged at 154g per kilometre. Both petrol models get a 68-litre tank and require 95RON fuel.

Infiniti says the V6 petrol engine in the Q50 Red Sport should use 9.3L/100km if you're using it on a mix of highways, urban streets and country roads. We only had the Q60 Red Sport for 48 hours and after a couple of days of Sydney city commutes and a trip to the Royal National Park our trip computer was reporting 11.1L/100km.

BMW's pre-drive briefing was so technology focused we half expected the black turtle neck and dad jean-wearing ghost of Steve Jobs to emerge from behind a curtain clutching an iPad. Only a minuscule portion was dedicated to the cars' drivetrains, with BMW instead hammering home autonomy functions, technology upgrades and the fact that its car was a preview to "the future".

But once we'd slipped behind the wheel of the all-new 5 Series, it all started to make more sense. Having briefly sampled three models (the 530i, 530d and 540i), we can safely report there's nothing particularly revolutionary about their on-road behaviour. That's not necessarily a bad thing - they do everything you could ask of a car in this bracket. They're mostly smooth and always quiet, the new chassis has done nothing to dampen engagement when you start to ask a little more of it, and it's generally a luxurious experience. But then so was the old car.

But what's new is the technology poured into the 5 Series. Every car gets what BMW is calling its personal co-pilot, for example, which is a set of tricky systems (there's six cameras, five radar sensors and 12 ultrasonic sensors scattered around the car) that work with the active cruise control and allow the car to be driven completely autonomous for 30-second intervals. Now, it's not quite as advanced as some of its competitor's systems - it can't change lanes for example - but if you're out on a country road or on a highway, it will stay within its lane, turn around corners and keep up with the traffic, even if they stop in front of you.

This is a full-size sedan, and every seat feels spacious and airy.

While the cheapest diesel model has historically been the best seller, BMW is hoping the new 530i will prove the most popular this time around. And while you couldn't describe it as fast, the power from its four-cylinder engine is ample for all that will likely be asked of it, and it feels sorted and composed on  more challenging roads. It's a smooth and comfortable ride, too, even with the optional 20-inch alloys fitted, though that's undoubtedly thanks to the adaptive dampers and ever-changing dynamic ride function, both of which are fitted as standard. In fact, we're yet to drive a car without those options fitted, so we're forced to reserve judgement on the as-standard ride quality of the cheaper models.

Be warned though, none in the 5 Series range offer the disconnected and perfectly smooth conveyance you might find in some true luxury offerings, and you'll still know when you're diving into deep pockmarks in the road. But the trade off is a an engaging ride and steering set up that always feels planted, with enough feedback to ensure you feel connected to what's happening beneath the tyres. And that's a trade we're more than willing to make.

Step up to the 540i and things take a much sportier turn. The turbocharged six-cylinder feels right at home in a car this size, with acceleration effortless and freeway overtaking manoeuvres an absolute breeze. And while we didn't find roads quite brutal enough to really test the active anti-roll bars housed at each axle, there's a wonderful and stable flatness to the way the biggest petrol handles corners.

It's not cheap, but thanks to the bigger engine and sorted dynamics, the 540i feels most like a 5 Series probably should.

Perhaps the biggest complaint we had about the previous Q50 Red Sport, which launched in 2016, was that it felt as though the chassis wasn't up to the amount of grunt running through it, and those rear wheels struggled to transfer the oomph to the road without losing traction.

We experienced the same issue again in this new car. I was breaking traction, not just in 'Sport+' and 'Sport' modes, but in 'Standard' and 'Eco', too. That was happening without pushing it hard and with all electronic traction and stability aids on.

If I was 18 I'd declare to the world I'd found my dream car - something that always wants to 'light 'em up' given half a chance. But like that one mate who always gets into trouble on a night out it's only funny when you're young.

A truly great performance car is planted, balanced and able to deliver the grunt to the road effectively. The Nissan R35 GT-R is the perfect example – a brilliant piece of machinery, a weapon of a performance car and with a chassis matched perfectly to its engine.

And that could be the issue with Q50 Red Sport - that engine feels overpowered for the chassis, and wheel and tyre package.

We also felt the previous Q50 Red Sport's ride, with its constantly adapting 'Dynamic Digital Suspension', was overly busy. Infiniti says it has developed the suspension system further and it does feel as though the ride is more comfortable and composed.

Steering was another area that we weren't overly impressed with when we drove the previous car. Infiniti's 'Direct Adaptive Steering' (DAS) system is super sophisticated and was the first in the world not to have any mechanical connection between the steering wheel and the wheels – it's all electronic.

The new Q50 Red Sport uses the upgraded 'DAS 2' and while it feels better than before, it's only in Sport+ mode that it seems most natural and accurate.

The Q50 was given the maximum five-star ANCAP rating in 2014 and the amount of advanced safety equipment which comes standard on the Red Sport is impressive. There's AEB, that works forwards and when you're reversing, forward collision and blind spot warning, lane keeping assistance and moving object detection.

There are two ISOFIX points and two top tether anchor points in the back row, for child seats.

The Q60 Red Sport doesn't come with a spare tyre because the 245/40 R19 tyres are run flats, which means even after a puncture you should be able to keep driving for about 80km. Not ideal in Australia where distances are seriously vast.

The BMW 5 Series is covered by a three year, unlimited-kilometre warranty, and requires condition-based servicing (rather than a pre-defined service interval).

You can also prepay your maintenance costs for five years/80,000kms, with prices ranging from $1,640 for the basic package, and climbing to $4,600 for the all-inclusive option.

The Q50 Red Sport is covered by Infiniti's four year/unlimited kilometre warranty with servicing recommended every 12 months or 15,000km.

Infiniti has a scheduled servicing program which will cost $1283 (in total) for three years.