well, believe it or not, the lower the aspect ratio your tire is, the stiffer it is....
stiffer is better for corners.. but not so much for traction in general.. you see in order to grip the pavement a tire needs to "wrinkle" or give a bit to allow more contact patch...
if you have a stiff 205/40 on a 17 inch rim the patch of rubber touching the tar is about 1.5 inches x 6.5 inches or so... on a 14in rim with a 55 or 60 aspect a larger patch of about 2.5 inches x 6 inches is touching the tarmac.
but with a 14 with a 60 aspect. that same give in the aspect of the tire becomes squishy in the corners... so to balance out squish in the corners and squish in a straight line is the idea... lets just put it this way ,
a 14in. with big aspect will give straight line traction...
a 17in. with small aspect will give corner stiffness...
a 16in. with a medium aspect will give a balance of both...
now it goes beyond that, to compounds, and silca content, and theres other tradeoffs like dry weather traction and wet traction, and treadlife (grippy tires dont last long, and long wear tires dont grip woth a beans)... its a science...
but rule of thumb with tires is, you get what you pay for...
an 80.00 17in tire aint gonna grip much... but you dish out about 130.00 and you start to get grippy tires...
with the 16inch wheel its the same rule, but at 60.00 you aint gonna grip much.. but you spend 90-100.00 on a 16 inch tire and you start to get what you paid for...
dosent sound like much 30.00 for a similar quality 16 in. to 17in. but x it by 4... your gonna spend 120.00 more for the same quality 4 tires on 17 inch than on a 16 inch...
those two things, are how i justify my 15lb. 16 inch 5zigens with BFG g force tires.. and i dont spin much after i get past that insanely short 1st gear in our cars..
..Joe....RCICustoms..