The A4, which has its engine placed in line with the car, will enjoy the same advantages as the A3 with MQB.
Audi will save on future A4 costs by building on a flexible VW platform.
The lower-cost production is three years away for Audi's bread-and-butter A4 model, but Audi confirmed this week that the A4 will get a similar one-size-fits-all platform from 2015 as Volkswagen Group introduces its MLB system -- the sister design to the radical MQB platform just launched in the Audi A3 and Volkswagen Golf.
MLB is the platform for longitudal engine layouts while MQB is for transverse layouts. The A4, which has its engine placed in line with the car, will enjoy the same advantages as the A3 with MQB - the potential for lower car costs in the future, lighter weight, better fuel efficiency and lower emissions, the simplicity of common components and faster production.
Like the A3's platform - which is now being morphed into underpinning the Tiguan, Q3, Skoda Octavia and Seat Leon plus a raft of future models - the A4's new design will be used on the next Audi models but has direct applications in the Volkswagen Phaeton (effectively an Audi A8); SUV models from Volkswagen, Audi and the upcoming Skoda; Bentley Continental; and even the 2014 Porsche Macan SUV.
Audi is by far the biggest user of platforms with the engine mounted in line with the car and predominantly driving the front wheels. A spokesman says the current Audi A4 has a platform that uses the principles of MLB but that the 2015 model will employ all the common design points that will allow it to be used in other makes and models.
Volkswagen Group plans four distinct platforms - MQB and MLB, one for rear-engined cars and one for mid-engine sports cars - in its quest to boost production, lower costs and maximise profitability on a path to become the world's biggest vehicle maker by 2018.