Groundbreaking petrol powertrain promises diesel-like fuel efficiency; it's on display at the LA motor show
Sam Sheehan
29 November 2017

Infiniti is bidding to crack Britain with its new QX50 – a car design boss Alfonsa Albaisa believes will finally show “the true potential of the brand”.

The Audi Q5 and BMW X3 rival, which slots into one of Europe’s fastest-growing segments and is on display at the LA motor show, will be the world’s first production car to feature a variable compression ratio petrol engine.

Autocar has already driven the QX50 prototype. Click here to read the review

The turbocharged 2.0-litre four-cylinder unit, called VC-Turbo, promises up to 35% improvements in efficiency compared to the old QX50’s 3.5-litre V6. It can seamlessly shift its compression ratio from 8:1 (for performance) to 14:1 (for economy), essentially giving the 268bhp and 280b ft engine the best traits of petrol and diesel engines.

The technology works by continuously raising or lowering the pistons’ reach to adjust the compression ratio. The movement is controlled by a multi-link system, the world’s first in a production car, and an electronic motor with a Harmonic Drive reduction gear that can move the crankshaft to alter piston position.

This new high-tech engine comes mated to a continuously variable transmission – the most efficient gearbox type – and drives the front wheels in standard form, although all-wheel drive is also available. The engine can accelerate the QX50 to 60mph in 6.3sec and on to a top speed of 143mph.

Infiniti’s sleek new model, inspired by the QX50 Concept of 2016, features a new platform the brand claims offers best in class cabin space. Boot space is 895 litres with the rear seats up, which is 345 litres more than the X3 and Q5. Space grows to 1048 litres with the rear seats forward, when they also offer the maximum 838mm of rear leg room, and 1699 litres with them down.

The torsional rigidity of the platform is up by 23%, improving refinement, while a noise-cancelling system reduces external sounds penetrating the cabin. Wind noise is also down thanks to a 6% more slippery exterior.

Inside, there are four monitors: a head-up display, instrument display between the speedometer and rev counter, as well as two touchscreens in the centre console. The upper 8.0in screen displays navigation, while the lower 7.0in screen displays apps, climate control and the car’s entertainment menus. It can also show the car’s 360-degree surroundings.

Propilot Assist technology allows the car to control the throttle, brakes and steering on a single-lane carriageway, bringing the car to a stop and accelerating in traffic. Additionally, the car is equipped with lane departure warning, forward collision assist and forward emergency braking with pedestrian detection technology.

Infiniti offers its QX50 with the choice of two steering systems: its digital Direct Adaptive Steering or conventional electronic power steering. The former does away with a steering column and replaces it with high-speed electric motors and sensors. As such, there is no physical connection between the wheels and driver, with Infiniti claiming that the Propilot Assist technology is most effective with this setup.

Alternatively, buyers can choose a conventional ESP steering system that uses a column assisted by an electric motor. The motor’s assistance decreases as speed builds, making the car easier to manoeuvre at low speed and more stable at high speed.

Infiniti’s sharper-looking QX50 will be produced alongside Mercedes-Benz models at its Aguascalientes plant in Mexico. The brand link comes due to an earlier partnership where shared platforms have been developed, however, the QX50's unique powertrain ensured that it would require its own underpinnings.

The QX50 will first make it onto US roads at the start 2018 before heading to Britain late in the year. Expect prices to start from around £35,000.

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Comments
13

24 November 2017
A+ for the new engine tech and an F for saddling it with a CVT box.

24 November 2017
MarkII wrote:

A+ for the new engine tech and an F for saddling it with a CVT box.

 

don't think you read a proper test drive report fo this car then !

24 November 2017
mpls wrote:

MarkII wrote:

A+ for the new engine tech and an F for saddling it with a CVT box.

 

don't think you read a proper test drive report fo this car then !

You think wrong then!

The test of the prototype clearly said 'despite being fitted with a CVT as standard...', which acknowledges the fact that CVT boxes are in general pretty rubbish compared to an epicyclic auto, dual clutch or (obviously) a manual gearbox.

Were it not for the fact that Nissan are heavily invested in CVT manufacture, I suspect their engineers would have used a traditional autobox and optimised its programming accordingly.

So I stand by what I said earlier about saddling this car with a CVT box.

24 November 2017
MarkII wrote:
mpls wrote:

MarkII wrote:

A+ for the new engine tech and an F for saddling it with a CVT box.

 

don't think you read a proper test drive report fo this car then !

You think wrong then! The test of the prototype clearly said 'despite being fitted with a CVT as standard...', which acknowledges the fact that CVT boxes are in general pretty rubbish compared to an epicyclic auto, dual clutch or (obviously) a manual gearbox. Were it not for the fact that Nissan are heavily invested in CVT manufacture, I suspect their engineers would have used a traditional autobox and optimised its programming accordingly. So I stand by what I said earlier about saddling this car with a CVT box.

 

https://www.autocar.co.uk/car-news/new-cars/first-drive-infiniti-qx50-prototype

 

I standy my point, note the bit after it says despite..  I'd arther live with that than wilth any diesel powered car/suv..

 

24 November 2017
mpls wrote:

MarkII wrote:
mpls wrote:

MarkII wrote:

A+ for the new engine tech and an F for saddling it with a CVT box.

 

don't think you read a proper test drive report fo this car then !

You think wrong then! The test of the prototype clearly said 'despite being fitted with a CVT as standard...', which acknowledges the fact that CVT boxes are in general pretty rubbish compared to an epicyclic auto, dual clutch or (obviously) a manual gearbox. Were it not for the fact that Nissan are heavily invested in CVT manufacture, I suspect their engineers would have used a traditional autobox and optimised its programming accordingly. So I stand by what I said earlier about saddling this car with a CVT box.

 

https://www.autocar.co.uk/car-news/new-cars/first-drive-infiniti-qx50-prototype

 

I standy my point, note the bit after it says despite..  I'd arther live with that than wilth any diesel powered car/suv..

 

As I said, I've read the articld on the prototype, so you don't need to point it out again.

If CVT was such a fantastic transmission there would be no need for the word 'despite', which clearly indicates that the car is hamstrung by the choice of a CVT box.

If the article said, 'the CVT box in the QX50 was a revelation and surprised with how efficient and responsive it was in comparison to a standard auto' then I wouldn't have commented but daying 'despite...' in this instance is like saying 'despite being fitted with rear wheel drive, the 600hp xxxx had good traction', true but the fact is that a 4 wheel drive version would have offered superior traction.

Haven't a clue why you're going on about diesel, I simply said that IMO this car would have been better without a CVT box, end of.

24 November 2017

The thing is Turbo, VVT etc are possible/economic on super mini's will this tech be scalable?

Just as important is it more economically than a plug-in hybrid?

 

Hydrogen cars just went POP

24 November 2017

Is this similar to Mercedes' DiesOtto engine which they working on around 10 years ago or so ago and was due to appear in some of their cars by now? If it is, could this be the same engine which Infiniti are using first as part of the Nissan/Renault/Daimler alliance?

24 November 2017
Lanehogger wrote:

Is this similar to Mercedes' DiesOtto engine which they working on around 10 years ago or so ago and was due to appear in some of their cars by now? If it is, could this be the same engine which Infiniti are using first as part of the Nissan/Renault/Daimler alliance?

 

different engine. merc couldn't get it to work..

24 November 2017
mpls wrote:

Lanehogger wrote:

Is this similar to Mercedes' DiesOtto engine which they working on around 10 years ago or so ago and was due to appear in some of their cars by now? If it is, could this be the same engine which Infiniti are using first as part of the Nissan/Renault/Daimler alliance?

 

different engine. merc couldn't get it to work..

This just highlights Mercedes' lack of engineering prowess and technical knowhow. I'm sure this new engine will find its way in to some Mercs in the same way some superior Renault engines already do. 

24 November 2017
Roadster wrote:

mpls wrote:

Lanehogger wrote:

Is this similar to Mercedes' DiesOtto engine which they working on around 10 years ago or so ago and was due to appear in some of their cars by now? If it is, could this be the same engine which Infiniti are using first as part of the Nissan/Renault/Daimler alliance?

 

except for the heavily polluting Renault diesels eh 1  in both Renault and Nissans..

 

different engine. merc couldn't get it to work..

This just highlights Mercedes' lack of engineering prowess and technical knowhow. I'm sure this new engine will find its way in to some Mercs in the same way some superior Renault engines already do. 

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