My E53 was a 2001 it had quoted 184 (193 actual) bhp, when they were facelifted 2004ish they went to 218 bhp and that is where E53 stayed. E70 was launched with 235 bhp and 230 odd grams of whatever which put it into the £400 + Road Fund class, about the end of 2007 they did some alterations that brought it down to 214 grams which reduces the Road Fund down to the same as the SD on £245. The SD was launched with 286 bhp and i think 426 lb ft of torque and puts out 216 grams, hence £245 Road Fund. Since Lci and now 40d it puts out 306 bhp and 340 odd ib ft and is 180 odd grams so road fund licence has fallen.