The Plus version of the Audi RS 6 could have up to ten percent more power.

Hot on the heels of Mercedes-Benz raising a trump card in the super-saloon power war with its new 430kW/800Nm E 63 AMG S model, comes news that it could face a potentially more powerful rival from Audi.

In an interview with the UK's Car magazine, the head of Audi's Quattro division, Stephan Reil, revealed that Audi is plotting a 'Plus' variant of its RS 6 Avant. This development could see its 4-litre V8 twin-turbo tweaked to produce up to ten percent more power than the current 412kW model.

The result would be a power figure of up to 447kW, which could shave more than just a few split seconds off the wicked wagon's zero to 100km/h sprint time of 3.9 seconds.

The power war looks set to rage on and the rivals may just feel the need to satisfy performance fanatics by loading their engineering canons.

If not, the 412kW BMW M5 will soon seem like the performance equivalent of a flat Holsten beer. And that pretty new feline from Britain - the 405kW Jaguar XFR-S - may just end up looking like a shaved pussy cat next to the Ingolstadt beast.

When is this crazy power war going to end?

In the past we've criticized cars in this bracket for not instead seeking lightweight solutions as a route to thunderous performance, and Car's interview reveals that this aspect is on Audi's radar for future RS models. Perhaps sanity will eventually prevail.