The 1.6TDI 105 should be comparable and should be more economical, but is saddled with a diesel particulate filter. With your mileage this should not be a problem, but the 1.6 has not lived up to its promise 100 per cent. 16-inch wheels will have 205/55 R16 tyres, while 17-inch wheels will probably have 215/45 R17 tyres. The difference between the 55 and the 45 is the amount of tyre between the rims and the road, and this seriously affects ride comfort. The 45s also wear faster, are more vulnerable to damage and are more expensive to replace. Go for 16s.