The king is dead - or so Audi would have you believe.
Yes, the mighty BMW 535D - crowned supreme ruler of the diesels for the last decade - has finally met its match.
The stats alone will make your eyes water - boasting an unrivalled 313bhp and a 0-100kph sprint of just 5.1 seconds.
The twin turbo, V6 is packing enough torque to pull down a house and constant all-wheel drive Quattro means it'll eat corners for breakfast.
Pound for pound it trumps the Beamer on horses, torque and acceleration and only falls short on CO2 emissions.
Still, a family saloon with that kind of grunt which is capable of returning over 42mpg (6.4l/100km) is no mean feat - even in the uber-efficient world of a Bavarian boffin.
It looks absolutely savage too with stonking 20 inch alloys in 5 arm Rotor design (option), lowered suspension and smoked-out rear windows.
Inside it's executive luxury all the way with soft Valcona leather at every touch and heated front seats as standard.
The list of inclusive kit on the S Line test car is generous by Audi standards and includes climate control, cruise control, Bluetooth interface, Audi Drive Select, Driver Information System – all displayed on a slim, 7 inch colour monitor which retracts into the dash.
Body-wise, you get sports suspension, full S Line body kit with Platinum front spoiler, diffuser lip, chrome tail pipes and 19 inch twin spoke alloys.
The trademark Xenon lights with LED surrounds complete the beastly look.
But we're in Supersaloon country so lookin’ pretty is not enough - you gotta walk the walk or in automotive terms - “drive the drive”.
Wow … and what a drive it is?
The raw power is nothing short of spectacular.
Open the taps and hell on earth is unleashed as the double turbo set-up gets about catapulting this hulking (almost 2- tonne) limo along the tarmac at a Ferrari-like speed.
The eight-speed automatic tip tronic gearbox is sublime and twinned to the Audi Drive Select means you can potter about town in the lap of luxury and should the road and mood take you - a swirl of the knob and it's hooligan time.
In Dynamic mode the suspension, steering and gear ratios alter, the sports diff kicks in and you're ready for some serious fun.
The Bi Turbo even comes with its very own soundtrack - the gravelly growl of a V8 petrol, thanks to a very clever acoustic boom box in the exhaust.
It may sound like a pointless gimmick, but it’s the one thing that really puts a pep in your step and more importantly - a grin on your face.
Ticking over it sounds like its idol, the epic RS6, as the snarling grunt grows louder the more you bury the throttle into the carpet.
Release the anchors and it propels you at phenomenal acceleration with seamless gear changes while the Quattro provides unprecedented grip.
Push it even further and the on-board computer tightens the steering, firms up the shocks and heightens the cars responses enabling the driver to thrash it in and out of tight bends as if it were a little hot hatch.
No once did it lose traction or indeed composure and at times you find yourself questioning why you’d even bother with a petrol – even the mighty S.
When you’re finished having fun, turn the dial to Efficient and you’re back to reality and off on the school run.
The Bi Turbo Quattro really is the complete package – a super saloon that is as quick as a Lambo, as comfortable as a limo and as cheap to run as a super mini.
The tax disk which reads Band D (€570 annually) is almost as unbelievable as the breath-taking performance.
It’s not cheap though and a starting price of €71,320 runs quickly North of €85,000 with a few goodies including the reversing camera with 360 degree birds eye view.
So, is the Bi Turbo a worthy contender to overthrow the 535D?
As I stated earlier the tale of the tape is so close it’s hard to call, but the Quattro just gives the Audi the edge.
Arise…. Your Majesty!