On standard rims 235 tyres will rub on the chassis at full lock.
My 02 Model runs 215/75/16 tyres as standard on 6 1/2 inch wide rims.
Then Offroad I have a set of 225/75/16 (roughly the same diameter as what you are looking at) muds on 7 inch wide rims these are from a 5 dr model which have a more negative offset (they stick out further from the guards) as a result on standard suspension when I originally put these on I was actually getting the tyres hitting the inside lip of the guard when hitting potholes etc in the road going down the motorway (not even offroad), solved this with a suspension lift. But the standard rims would probably not have had this problem. The 5dr rims do not rub anywhere on the chassis.
Powerwise, I also have the 1.6 its still fairly respectable with the larger tyres and it will cruise at 100km/hr fine (although speedo will be out), you will find you need to work the gears more uphill.
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