VW unveils next Golf’s ‘MQB’ underpinnings
BY HAITHAM RAZAGUI | 3rd Feb 2012
The German giant has also issued information about the lightweight new four-cylinder petrol engine family – claimed to be the world’s first mass-produced four with cylinder deactivation – that will complement the MQB platform alongside revised diesel units.
Not only is it flexible enough to form the basis of products from the Polo light car through to the Passat mid-sizer with people-movers and SUVs in between, it is claimed to reduce the weight of each car by at least 40kg.
VW says the result of its weight saving efforts will mean the seventh-generation Golf will weigh roughly the same as the MKIV model produced from 1997 to 2003 despite the inclusion of more safety, comfort and convenience technology.
The architecture is also said to enable safety assistance, connectivity and infotainment systems usually associated with larger and more expensive vehicles to trickle down to volume-sellers like the Golf.
Although VW unveiled the naked chassis and drivetrain of its next-generation Golf in Wolfsburg this week, the first public outing of MQB was at the Tokyo show in November with the Cross Coupe SUV concept that previewed the next Tiguan.
A further MQB-based concept is highly likely to take pride of place on VW’s show stand at the Geneva show next month.
Long a master of platform- and parts-bin sharing, Volkswagen is naturally making the most of MQB’s ability to yield even greater economies of scale in parallel with its new Modular Production System (MPB), which will give it the ability to produce different MQB-based models – even those of different brands – on the same production line using the same robots.
One of the first examples of this will be at Volkswagen’s new Foshan plant in China, where from mid-2013 the Audi A3 will be built alongside the Golf.
Volkswagen says MQB and MPB will deliver “exciting opportunities” for suppliers to increase throughput and automation as it expects its component purchases to “nearly double” by 2018.
But it is clearly aiming to make cost savings, saying the new architecture will enable suppliers to “offer their services at extremely competitive prices”.
MQB is part of a plan to reduce the number of Volkswagen Group platforms to four, sitting between the New Small Family architecture used by the Up city car and its derivatives and the premium-oriented Modular Longitudinal Platform (MLB), for which Audi is responsible, while Porsche looks after the Modular Sportscar Matrix.
VW says MQB gives each car uniform engineering dimensions, such as the engine mounting position and the distance between the accelerator pedal and the front wheel, while enabling the wheelbase, track and wheel size to vary.
For example, both the new petrol and diesel engines now share a basic layout with the exhaust facing the rear of the engine bay, meaning they can slot into the same mounting points and be connected to the same transmission.
Tilting the engine 12 degrees towards the rear of the engine bay reduces the mounting length by 50mm, which combined with moving the front wheels forward by 40mm increases interior space and helps improve crash performance.
MQB-based vehicles will save around 18kg through the use of high-strength steel across 85 per cent of the body structure with the side benefit of improving crash performance.
The floor structure is also 18 kg lighter and VW has future-proofed the MQB architecture with the provision to attach aluminium panels in place of steel on future products, while interior components will be more than 10 kg lighter.
In addition, MQB has seen running gear go on a diet, losing 6kg and helping to improve ride and handling in the process, with savings of roughly 3kg also made in the electrical systems.
Expect even more obscure niches to be filled too, for VW says the MQB gives it the freedom to expand into product types that “could not be served until now”.
The new EA211 engine family – which includes the three-cylinder units used in the Up city car – only shares cylinder spacing with the four-cylinder EA111 series it will replace.
To be built in turbocharged four-cylinder format with 1.2-litre and 1.4-litre displacements, the EA211 is claimed to reduce fuel consumption and CO2 emissions by between eight and 10 per cent.
The 1.2-litre unit will initially be available in 64kW/165Nm and 77kW/175Nm tune, while the 1.4-litre will come with 90kW and 200Nm or 103kW and 250Nm, with all variants developing maximum torque from 1400rpm – 4000rpm.
VW says the 103kW engine will be the world’s first production four-cylinder to include cylinder deactivation and claims the system can reduce fuel consumption by up to 20 per cent.
Switching between four- and two-cylinder operation takes half a camshaft rotation, a barely noticeable 13-36 milliseconds depending on engine speed and because the engine is “excellently balanced” it is said to run equally quietly and smoothly in either mode.
In normal use, the engine runs on two cylinders between 1250rpm and 4000rpm and when torque requirement is in the region of 25-100Nm, although the system can detect “irregular” driver behaviour and ensure constant four-cylinder operation when full engine responsiveness is required.
Also improving efficiency are reduced internal friction and optimised thermal management – including an exhaust manifold with its own cooling jacket integrated with the cylinder head – plus improved precision in the fuel injection system along with updated idle-stop and regenerative braking systems.
An aluminium block and other internal weight-saving measures yield a 22kg saving on the 1.4 – with the move to an aluminium block saving 16kg alone.
VW’s modular philosophy was also applied to engine construction, with all variants sharing identical components such as the air filter, induction pipe, intercooler, and throttle valve.
The EA288 diesel engine, available in 1.6-litre and 2.0-litre displacements will be available with power and torque outputs ranging from 66kW and 250Nm to 140kW and 380Nm.
CO2 emissions are claimed to be reduced by up to 45 per cent in Euro 6 version, while there are performance gains up to 12 per cent across the line-up, with some configurations improving by an impressive 26 per cent, although VW provides no direct comparisons.
Designed to comply with emissions regulations all over the world, the new diesel engines again follow the modular philosophy, with various common emission control components that can be bolted on to satisfy ever-changing legislation in VW’s many global markets.
As with the EA211 petrol engine, the EA288 diesels share only their cylinder spacing with the units they replace. The application of similar thermal management and friction-reducing measures help lower emissions and fuel consumption while the addition of balancer shafts help improve refinement.
The MQB architecture will also result in more VW Group products receiving technology like traffic sign recognition, fatigue detection and adaptive cruise control, plus collision mitigation systems like pre-emptive braking and assisted lane-keeping.
VW says the next-generation Golf and Audi A3 will come standard with a ‘multicollision brake’ system that detects an impact and automatically applies the brakes to prevent the car from being shunted into oncoming traffic while activating the hazard lights.
A new limited-slip differential system combining mechanical and electronic systems claimed to eliminate the traction disadvantages of front-drive vehicles will also debut with the MQB platform, as will an improved electro-mechanical steering system dubbed progressive steering.
Rounding out the technological advancements will be a smartphone-style touch-screen interface for infotainment functions.
