Not sure if it applies to the 19's (I imagine it does) but the load index for for the rear tyres on the 20's is 110, the front is 106 or 107. I think the difference in load capability is 100 kg or so on a car of the X5's weight is not big. I was going to fit some Michelin Diamaris to my X5 but they are only 107 too.....the supplier I askd to quote for them said they weren't suitable for the car on that basis.