B9.5 Audi RS 4 Test Mule Spied

With the so-called “B9.5” range of A4 and S4 mid-lifecycle product improvements now revealed, it’s only a matter of time before the B9.5 RS 4 Avant also takes its bow. As if on cue, an RS 4 Avant test mule has now been spied.

Like its other B9.5 A4/S4 siblings, the RS 4 will get new headlights, taillights and trim like the singleframe grille. While it’s doubtful at this time that the RS 4 will get a more powerful engine, that doesn’t mean that Audi doesn’t have a card to play in this regard. How so? Let’s do the math.

The B9.5 range will get mild hybrid architecture. In the case of the S4 TDI in Europe, this means 48v hardware. For those keeping count, 48v electrics means the engineering potential for a turbocharger with electric assist… basically using electrics to spin up a turbo preemptively for immediate boost.

Now consider the new S6 and S7. U.S. versions will be getting the same 2.9 TFSI biturbo as seen in the RS 4 and RS 5, but with an electric turbo and 48V electrics. Theoretically, this hardware could be combined with the 48v electric components of the S4 TDI and voila. 

While U.S. versions haven’t been fully revealed, Audi did mention the electric turbo spec and also the power figures in their initial S6/S7 reveal. We detailed that a few months back HERE. Power figures provided then were 450 hp and 600 Nm (442.5 lb-ft). As you can see, that wouldn’t mean much of a gain from the current RS 4’s 450 bhp and 600 Nm, but other examples of 48v e-turbo applications suggests more immediate torque and improved fuel economy.

Of course, whether or not Audi does go 48v on the RS 4 remains to be seen. For now, that tech is only confirmed in the European market S4 TDI. 

See more photos below.