x5 e53 alloys

[steven]

hi
i have been told by the dealer that the new 19" 5 spoke alloys with run flat tyres will fit the older e53 car , so i purchased a set to replace my 19" old set as i pull a large caravan & have young children i thought it would be the safest thing to do as the run flat tyres will not fit on the old wheels , the problem is that the tyres are the same but the offset must be slightly different as they are catching the rear arches & the front arches they have now said that i will need to put 5mm spacers on the car all around with longer bolts but as it is 2 tonnes i dont really want to put all of the stress on to the bolts instead of the hubs . can anyone make any suggestions the only thing i can think of is that the sport which is what mine is has lower suspension causing the wheels to tip in more on the e70 wheels than the e53 ones also they seem to have a smaller dish too them as the e53 ones are deeper ?
regards
steven