Audi will launch a new 230bhp 3.0-litre diesel version of its A8 luxury car in April.

The entry-level diesel will cost £47,380 - £10,180 less than the existing 4.0 turbodiesel. The new model undercuts Mercedes' 204bhp S320 CDi by £1450, but is £2820 more than BMW's 218bhp 730d.

With a standard six-speed Tiptronic automatic transmission, performance figures for the new A8 are slightly quicker than those of its rivals. Its fuel consumption is slightly better than the 730d's, although it's almost 10% worse than the S320 CDi's.

The Audi is clean enough to avoid paying the usual 3% company car tax penalty on diesel cars, and its emissions put it in the 31% tax band - one band higher than the Mercedes, but three bands lower than the BMW.

That means a higher-rate taxpayer will pay £5850 a year in tax on the A8, £5835 on the S320 CDi and £6033 on the 730d.