Yup it is impossible to make a rec without knowing the width and offset. But Obviously 285/30 will have a thicker side wall vs. 275/30 and will be more likely to rub.
Not giving out wheel offset is totally unacceptable, its like buying a car without knowing how many hp it makes.
2011 E92 M3 DCT
1991 Spec Miata
2008 E92 M3 DCT - KW Competition 2-way / Brembo 365 BBK / OMP ARS racing seats / rear seats delete / GT4 aero / AiM EVO4 data logger / SmartyCam racing camera
2008 E92 M3 6MT
2008 E92 335xi