My ML 270cdi (2000) has 17" rims with 275/55 R17 Tyre on them. These tyre are very expensive in Australia and hard to source in remote outback areas where I travel. (If I need a tyre I may have to wait days for a delivery from 1000s of kilometres away). Can I put 16" wheels and put the 225/75 R16 or 255/65 R16 Tyres on. These sizes are cheaper and more available in Australian remote areas?