Audi quattro ultra 4×4 system: limpet grip, with fuel savings

Audi has revealed the latest version of its quattro four-wheel drive system, called quattro with ultra technology. It will be fitted to the Audi A4, and also new versions of the A5 and Q5 when they’re released later in 2016 and early 2017. In time, all quattro-equipped Audis with longitudinally mounted engines could get the system.

Carrying the ultra name means this latest development of the company’s famous four-wheel-drive system is all about saving fuel and cutting CO2 emissions. Audi claims it will set benchmarks in both, with an average 0.3 l/100km boost to fuel economy when compared to the old quattro system. Theoretically, this system could take the 215hp, 3.0-litre diesel quattro Audi A4 model from 60.1mpg to an even more impressive 64mpg.

It works by allowing the car to run in front-wheel-drive mode – on dry motorways, say –  when the extra grip of four-wheel drive is surplus to requirements and serves only to put extra stress on the engine.

If it’s needed, power is sent to the back wheels via two clutches – one mounted to the car’s gearbox, the other to the rear axle – which can re-engage the engine following a three-step strategy, named: proactive, predictive and reactive.

The proactive stage refers to the car’s sensors, which relay data to the four-wheel drive system’s control unit, allowing the car to predict when four-wheel drive might be needed and to prime the system accordingly – the rear wheels being engaged before the front end’s limits of grip are reached. The real-world result is a seamless transition to four-wheel drive.

The predictive element takes account of the user’s driving style, the settings chosen in the car’s Direct Drive system and data form the stability control. In other words, if you drive aggressively the car will respond by switching on the four-wheel drive system to maximise performance and safety.

Think of the car’s reactive phase as a clever safety net and you won’t be far wrong. It’s likely to be used the least in the real world and responds to sudden changes in conditions – encountering a patch of sheet ice would do it – calling on the quattro system’s grip in an emergency situation.

Audi quattro ultra real-world test

We sampled the system fitted to a 2.0-litre 249hp Audi A4 TSI petrol on cold Austrian roads, where it performed without fault offering plenty of grip when accelerating and cornering – even a hard start from a snow-covered layby couldn’t provoke any wheelspin.

Audi wanted the system’s operation to be imperceptible and, if we did not have the benefit of an iPad hooked up to the car’s ECU (and an insightful engineer holding it), it would have been. In fact, four-wheel drive was called on no less than 39 times on our hour-long drive, accounting for 70 per cent of the journey, but only the car’s uncanny stability hinted at all the clever stuff happening beneath us.

The new quattro system is seen as an important contributor to Audi’s future success – hardly surprising when you consider it helped the company to three Le Mans victories and was fitted to 40 per cent of all new Audi’s sold in 2015.

Quattro with ultra technology should give the company an edge over BMW’s popular xDrive and Mercedes‘ 4Motion system, when it’s initially offered on the all new A4 Allroad scheduled to go on sale in the middle of 2016.

comments powered by Disqus