AUDI RS5 TDI
Audi has revealed a special new concept this week that could hint at a coming hero to take on BMW’s diesel-powered and M-tuned performance models.
The new RS 5 TDI concept takes the body and dynamics of its production sibling, but swaps the petrol V8 for a clever new twin-turbo diesel setup.
Rather than a conventional turbo system, the RS 5 TDI’s diesel sees the smaller of its two turbos assisted by an electric supercharger motor - a project first revealed back in 2012.
In a regular twin-turbo package, the smaller of the two units is used to spool up faster at low rpms, reducing turbo lag as a result.
By adding an electric motor to the formula, the reduced reliance on exhaust gases at lower rpms allows the smaller turbo to spool up even more quickly.
It’s a concept that is already in use in racing applications - including this year’s Formula 1 series - and in Audi’s case, the electric motor is used to spin the turbo to 3000rpm where exhaust gases then take over.
Audi says the system allows for faster off-the-line acceleration, with the added benefit of maintaining charge pressure when entering a corner, ensuring a quicker exit.
In the RS 5 TDI, the system is matched to Audi’s new-generation 3.0 litre diesel engine.
Producing up to 200kW and 600Nm in its regular guise, the engine’s electric-assisted application in the RS 5 TDI also gets a boost to 287kW and a whopping 750Nm of torque - the latter available from 1250rpm.
That means the souped-up diesel is still 48kW short of the petrol RS 5’s output, but betters its torque figures by a huge 320Nm.
Performance figures haven’t been offered, but a 0-100km/h time of around 4.0 seconds would not be out of the question. By comparison, the regular RS 5 claims a 4.6 second sprint.
A production debut for the new setup is yet to be confirmed, but a new diesel-powered RS model could be on the cards for 2015.
For now, diesel fans looking for a quick Audi can check out the 230kW/650Nm SQ5 SUV, the company’s first performance-focused diesel model.