The Jaguar XFR can now reach a new top speed of 280km/h in the UK after the addition of an optional Speed Pack.

The pack raises the electronically governed limiter of the flagship Jaguar XF model to lift its maximum speed from 250km/h, giving it an advantage over the rival BMW M5 and Mercedes-Benz E63 AMG that are still restricted to that 250km/h mark.

Jaguar has recalibrated the 5.0-litre supercharged V8 engine and eight-speed automatic gearbox to account for the boosted top speed, though there are no changes to acceleration time of 4.9 seconds that makes the British super sedan slower than its German competitors.

The Jaguar XFR Speed Pack model also gains a front aero splitter and a subtle bootlid-mounted rear wing.

The Speed Pack will become available from November in Australia as part of the Model Year 2013 updates for the Jaguar XF. Pricing has yet to be confirmed though is likely to cost at least $5000 based on the UK price of 2750 pounds.