Tyre size - 850 estate

The tyres are the same width but about 3% larger in diameter. I very much doubt whether there will be clearance problems because 850's and 70-series cars were fitted with a wide range of tyre sizes - some of which were probably bigger than these. You will, of course, get a speedo/odometer error of about 3% relative to current values. Speedos tend to be a bit optimistic anyway - so the larger tyres will probably bring it closer to the truth. But I would still calibrate the speedo with a GPS - or against motorway mile posts - to make sure that you don't inadvertently get done for speeding.