Wheel arch blisters, like those on the old RS6 and a feature on 1980s rally Quattros, are under consideration.
The interior will share much of its architecture with the Q5. It will be a five-seat cabin, with the central rear seat intended for occasional use.
Among the proposed engines are next-generation versions of the 2.0-litre turbodiesel with 170bhp and 210bhp, plus a 240bhp 3.0-litre V6 diesel.
They are likely to be joined in the Q4 line-up by a 270bhp naturally aspirated 3.2-litre petrol V6. In keeping with its sporting brief, the Q4 is also likely to spawn two separate S models.
One will be aimed at China, Russia and North America and feature Audi’s 328bhp supercharged 3.0-litre V6 petrol engine.
The other will be conceived for Europe and is set to be powered by the 308bhp twin-turbo 3.0 TDI V6 recently unveiled in the A6 Avant.
Read about the 308bhp twin-turbo 3.0 TDI V6 Audi A6
The same engines are set to find their way into more upmarket S versions of the Cajun, alongside which the Q4 could be assembled at Porsche’s Leipzig factory in Germany.
A low-emissions Q4 Hybrid model is likely, running the same driveline as the upcoming Q5 Hybrid. It combines a 208bhp turbocharged 2.0-litre petrol engine with a 34bhp electric motor.
If the Q5 Hybrid is any guide, it promises combined fuel consumption of around 40mpg and CO2 emissions of 159g/km.
Audi had expected the Q4 to face competition from the BMW X4 by the end of 2014, but it now appears that car won’t be launched off the existing X3 platform. Instead, BMW officials say plans for the X4 are on hold pending a new platform strategy that, they say, will centre on greater commonality between the X3 and X5.
The Q4 is just one of a handful of new Audi SUVs in the pipeline to meet the growing global demand for upmarket SUVs. Audi will launch three sporty 4x4s in the next five years.
The strategy will double the number of dedicated SUVs offered by Audi. In addition to the Q4, today’s Q3, Q5 and Q7 models will be joined by more overtly sporting Q2 and Q6 derivatives by 2016.
“It’s clear that demand for SUVs and crossovers is still in an upswing phase and will remain so for some years to come. We want to make sure we have the coverage to satisfy it,” an Audi insider revealed.
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