The twin-turbo diesel has gained performance as it progressed from 3.0sd, to 35d and now 40d. At the same time the single-turbo 3.0d and now 30d has also progressed so much so that the current model E70 LCI 30d isn't far behind the original E70 3.0sd. Note also that the 3.0d in the early E53 is nothing like the 3.0d that appeared in the 2004 update. In Australian spec the single turbo diesel has progressed from 135kW/390Nm in the early E53 to 180kW/540Nm in the LCI E70 while the twin turbo diesel has progressed from 200kW/565Nm to 225kW/600Nm. I believe that the state of tune of the UK models isn't too different from the Australian spec.