fransmart-madrid

Hallo aus Spanien, Ich werde mein Problem zuerst auf Englisch und dann auf Deutsch erklären (danke Google Translate) My name is Fran ,I have doing a reseach and after some days I found this post. I have a problem, I want to change wheels to my smart fortwo 450 I found brabus monoblock V wheels on second hand market. But there is something weird, the rear wheel has ET 0, but the original one has ET -1, de front one ET30 but the original ones ET 34. It has also engraved next to the inflation valve this-> KBA45138 but after looking for other monoblock V on the Internet, no one has this number on the visible part of the wheel. The photo the seller is showing is not very sharp, maybe the numbers differ... I reas something @josemarlangner put, but the translation from german to spanish is not very clear, and the link above does not work. Can this wheels be original?? why have they different ET?? What does KBA45138 means? Thanks for your time and I would appreciate any help. Fran