Lillee wrote:
If using the same 165/70R10 Yokohama AO32R tire (for example) on a 5 inch vs a 5.5 inch wheel, What is the technical difference? As in greater contact patch even though widths are the same?? does the tire sort of bulge out more due to the width of the wheel? Genuine question
AFAIK all other things being equal, a wider rim will cause the tyre to distort less when cornering, which means the car should feel sharper with better turn in, an analogy might be similar to if you were to raise your tire pressures a bit a bit less vague... if it were very stretched you might have to run less negative camber to get traction back but I doubt it in this case.
There are disadvantages if you stretch a tyre too much (boy racer style) but with a 165 we are aligning closer to the manufacturers specs.
Other benefits might be the A008s I was looking at were recommended for about a 5.5" tyre(not sure where I found that), which I couldn't get so it better matches the manufacturer specs, if it's going to fit without flares and is 1/2" wider it needs to be offset more towards the centre of the car (positive offset / ET? I always get confused) this gets it closer to centre point steering which is where the centre of the tyre lines up with a line drawn through the top and bottom ball joints... This does good things for handling as if your wheel hits a bump it has less leverage to turn the wheel and therefore try and steer the car, it would also be a large factor (I think) in managing torque steer as differing levels of grip are less likely to try and steer the car.
Please correct or expand if I got any of that wrong.