Audi RS5 vs Infiniti Q50

What's the difference?

Good looking, good to drive, and good to simply sit in, the Audi RS5 range ticks plenty of premium boxes. Whether you can live with the practicality pitfalls of the Coupe is up to you, but if you can't, might I suggest taking a wander over to our RS4 Avant review?

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.

I defy anyone to describe the RS5, and especially the Coupe, as anything but stunning. Seriously, the near perfect proportions and swept-back styling make it look fast even when it's parked. 

Up front, there's a new-look black-mesh grille that's been given a 3D effect, like it juts out over the road in front it, while the thing headlights have been carved back into the body work like they're been windswept under hard acceleration.

The 20-inch darkened alloys fill the arches, too, with a sharp body crease that runs from the front headlight all the way back to the bulging shoulder lines above the rear tyres accentuating the curves.

Inside, the RS5 is a sea of black Nappa leather and sporty touches, and we particularly like the chunky, flat-bottomed steering wheel, which both looks - and feels - great.

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.

We only tested the Coupe, and I can tell you that the practicality perks on offer largely depend on where you're sitting.

Up front, you're spoiled for room in the two-door Coupe, with the two spacious seats separated by a sizeable centre console that's also home to two cupholders and a variety of cubbies, with extra bottle storage in each of the front doors. 

The back seat, though, is a little, or a lot, tighter, with come acrobatics required to even climb into it, given the Coupe only has two doors. The Sportback offers two more doors, which will surely make the process a little easier. 

The Coupe measures 4723mm in length, 1866mm in width and 1372mm in height, and will deliver a decent 410 litres in luggage space in the boot. The Sportback measures in at 4783mm, 1866mm and 1399mm, and boosts your luggage space to 465 litres.

Either vehicle has your tech needs sorted, with an abundance of USB and power outlets serving both front and backseat riders.

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.

Its a terrific engine, this - a twin-turbo 2.9-litre six-cylinder TFSI that will deliver 331kW at 5700rpm and 600Nm at 1900rpm, sending it thundering to all four wheels (because quattro) via an eight-speed tiptronic automatic.

That's enough, says Audi, to deliver a 0-100km/h sprint time of 3.9 seconds in the Coupe and the Sportback. Which is very, very quick.

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.

The RS5 Coupe will sip a claimed 9.4L/100km on the combined cycle, and emit a claimed 208g/km of Co2. It's fitted with a 58-litre fuel tank. 

The RS5 Coupe will the same 9.4L/100km, but emit 209g/km of Co2.

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.

With our time behind the wheel limited to the RS5 Coupe, we can only really report on how the two-door feels on the road, but given the prodigious power on offer, it's unlikely the addition of two doors is going to make the Sportback any slower. 

In short, the RS5 is thunderously fast, collecting speed with utter nonchalance thanks to this thick and endless-feeling supply of power unleashed whenever you plant your right foot.

It makes even the most ham-fisted attempts at cornering feel fast as lightning, with the power flow able to make up for every slow entry and exit by simply piling on pace between bends. 

But that's what you expect from an RS model, right? So perhaps more impressive is the RS5's ability to transform back into a relatively sedate urban cruiser when the red mist subsides. The suspension is firm, especially over rough road surfaces, and you do need to be a little careful with the accelerator to avoid that lurching feeling at every green light, but driven calmly, it doubles as a everyday car quite nicely.

Like in the RS4, we did find the gearbox felt a little quick to change at pace, shifting up or down at strange moments on the way into or out of corners, but you can reclaim control via the paddle shifters.

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.

Audi vehicles are covered by a three-year, unlimited-kilometre warranty, which is feeling more than a little underdone when compared to some competitors.

Services are due every 12 months or 15,000kms, and Audi allows you to pre-pay your service costs for the first five years, at a cost of $3,050.

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.