Jaguar XFR-S priced at $222,545, XJR $298,000

The Jaguar XFR-S, the fastest and most powerful sedan the British manufacturer has ever produced, will retail at $222,545, a $32,645 premium over the regular XFR.

Although retaining a 5.0-litre supercharged V8 petrol engine, the XFR-S produces 404kW and 680Nm - up 29kW/55Nm on the XFR - and claims a 4.6 second 0-100km/h and (electronically limited) top speed of 300km/h. It gets a 'Quickshift' version of the existing eight-speed automatic transmission.

An electronic active differential and a reworked stability control system also feature, aiding power-down to the 20-inch wheels - 265/35 front/295/30 rear - with bespoke tyres.

With the XFR-S, lateral stiffness of the front suspension rises by 30 per cent compared with the XFR, while aerodynamic changes and the increased use of carbonfibre reduces lift by 68 per cent, according to Jaguar.

Inside, 'carbon leather' and contrast 'micro piping' on the seats differentiates this more hardcore version of the XF from the regular XFR.

Boasting the same engine and outputs as the XFR-S, the Jaguar XJR will become the flagship of the British limousine lineup when it arrives priced from $298,000.

Despite being less hardcore than its smaller XFR-S, the XJR claims an identical time to 100km/h although it has an electronically limited top speed of 280km/h.

Claimed to be "the most focused, agile and responsive Jaguar XJ ever made" the XJR also gets a new front splitter and other aerodynamic aids, an active electronic differential and unique stability control tuning, and 20-inch forged alloy wheels.

When it arrives in Australia later this year, the Jaguar XJR will be available only in short wheelbase guise from.

The Jaguar XFR-S, meanwhile, will arrive slightly earlier, likely in October or November.