Infiniti Q50 vs Jaguar XJ

What's the difference?

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.

It might be old and facing German competition bursting with advanced technology, but the XJR is still a car you can buy with heart and head. But mostly your heart. It goes like stink, has a much better interior than the Quattroporte and is more interesting than just about anything this big or this grand.

It's also a better car than the Maserati Quattroporte if you want to get on with the driving yourself and is far prettier than the Porsche Panamera. It's a wonderful thing and even more wonderful that Jaguar continues to build it. Long live that supercharged V8 and the XJ is a great home for it.

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.

The XJ has a marvellously exaggerated length, with a rear overhang redolent of Jag's sporting coupe and roadster pair of the time of its launch, the XK. There's nothing else in the segment like it, with the three Germans - Mercedes' S-Class, Audi's A8 and BMW's 7 Series - having gone all Hugo Boss and and in the latter two's case, almost shrinking violet. The only credible Japanese alternative, the Lexus LS, looks like a Lexused 7 Series. The XJR is a more emotional car, like Maserati's Quattroporte.

The R adds an aggro grille, 20-inch wheels with low-ish profile tyres, a bootlid spoiler, red brake calipers and vents in the bonnet. Bits and pieces get the black gloss treatment and there are V8 and R badges, as well as a rather large leaper on the bootlid. Capping it all off are four exhausts poking out from the bumper and distinctive vertical taillights.

Inside remains largely unchanged. The cabin is big and luxurious, leather-lined and very, very comfortable. The front air vents have to be modelled on the de Havilland Comet's integrated jet engine intakes and, again, the dash design stays away from the horizontal lines of its obvious competition.

There is probably a bit much chrome for my liking, particularly on the centre console and around the rotary dial shifter, which reflects sunlight into your face during the day.

The lovely 'Riva Hoop' - a band that sweeps from door to door across the top of the dash - is a great touch and remains a defining feature in the cabin. The last update brought an Audi-like digital dashboard, including maps, but it's not nearly as slick as the German. The graphics for the dials are good (and quick) but the maps are a bit so-so.

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.

It might be over five metres long, but the Jag's cabin isn't as gigantic as that might suggest - luckily, if you want space, the XJ L has it. The SWB version is roomy enough, though, just not palatial. You can fit five people, but the big transmission tunnel will limit the size of that fifth.

Front and rear passengers have a pair of cupholders each, with rubber bubbles to help hold smaller cups in tight. The front and rear doors have pockets but aren't really for bottles.

Boot space is a reasonable 520 litres, with a space saver spare under the floor.

As is expected at this level, Jaguar was not mucking about with price or specification - the XJR starts at a mildly terrifying $299,995, which is very close to the rather more tranquil Autobiography long-wheelbase relax-o-mobile.

Standard are 20-inch alloys, a 20-speaker stereo, power everything with three memory positions, four-zone climate control, keyless entry and start, front and rear parking sensors, heated and cooled front and rear seats, sat nav, LED headlights and DRLs, leather everywhere, auto wipers and (LED) headlights, electric boot lid, heated steering wheel and a space saver spare.

The Meridian-branded stereo is an absolute cracker, powered by the improved but still laggy 'InControl Pro' system. Oddly, it's all crammed into an 8.0-inch touchscreen when there is seemingly room for the larger (and better-performing) 10.0-inch screen. The software is far superior than the version that preceded the last update, but the screen is hard to use, as targets are placed right in the corners and are hard to hit.

Apple CarPlay and Android Auto are also absent, and the sat nav is still fairly dopey.

A long list of options are available, some of which should probably be included in the big sticker price - DAB+ ($620), premium paint is a splutter-worthy $2060 (although, to be fair, the vast majority of the 19 colours are free), adaptive cruise with queue assist ($2200), adaptive headlights a further $2620 and 'Parking Assist', which adds side sensors and a front camera, a further $2780. Reverse cross traffic alert, blind spot monitoring and forward collision warning cost yet another $1460. Ouch.

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.

Jaguar's lovely 5.0-litre V8 with supercharger continues under the XJ's long and shapely bonnet, delivering a walloping 404kW and a tyre-shredding 680Nm. The sprint to 100km/h for all 1875kg of XJR is completed in an impressive 4.6 seconds, which was very competitive at the car's launch in 2009.

Power reaches the rear wheels via ZF's eight-speed automatic and you can control it with the tacky plastic paddles on the steering wheel. Oh, and it has stop-start.

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.

The combined cycle figure for the V8 is listed at 11.1L/100km but fully expect to see the 16.1L/100km we got, especially as you try and fail to tyre of the monstrous power delivery and lovely (if muted) V8 roar.

Luckily, even if you're belting it, the 82 litre tank is a generous size and you'll cover a fair amount of ground.

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.

Indecently quick, surprisingly agile and heaps of fun. While the first descriptor applies purely because of its size, the next two shouldn't when you're in command of 5.13 metres of motor vehicle. As with the Audi and now the 7, the Jag has a lot of aluminium to help keep the kilos off and good gracious, it has worked.

The R is based around the short wheelbase version of the XJ for perhaps obvious reasons. Even so, it appears to be the shorter-again XF's because this thing turns in like a demon. No, it won't stay with the dearly-departed XF-R but it does a mighty fine impression of one, just with a better ride quality.

Rear seat passengers should be prepared to feel a lot of wheelslip, especially when in Dynamic mode, as even the fat Pirelli P-Zero's struggle for purchase when the right foot hits the carpet. The V8 rumbles rather than bellows, but the rears cheerfully spin up until the computers and active differential rein things in. Traction control off and you've got a proper tyre-smoker if you're not playing by the rules. Jag's engineers are clearly hooligans at heart.

As always, ZF's eight-speed transmission does an incredible job of marshalling the horses in a rearward direction and when you're not after a bit of sound and light, have achieved a tremendous amount with the damping. When in normal mode, the car glides along, so much so that the lady of the house wasn't so sure it was a sporting sedan.

Once she was apprised of dynamic mode (you have to cycle the button through winter mode first, for some reason), her only complaint was that it was too long and the steering wheel too big for this type of car. I was persuaded of the latter, especially after stepping out of an Audi S3 which has a tiny wheel. Long story short, the XJR is now 'her' car (to be more accurate, the XFR is, but that hasn't arrived yet, so...), as it felt smaller than it was when not parking and she's a sucker for a torquey V8.

The whole XJ range has six airbags, ABS, stability and traction controls, emergency brake assist, reversing camera, three top tethers and two ISOFIX points. The XJ doesn't have an ANCAP safety rating.

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.

Jaguar offers a three year/unlimited kilometre warranty and roadside assist for the same period.

Like the F-Type, XJ owners benefit from three years/100,000km free servicing.