[Payton King]

opinion based on discussions over the years. The 15 inch steel rallys I had with a 235/60/15 weigh more than my 18 or 19 inch rim and tire. The diameter of the overall package is not any different on the 18 set as opposed to the 15 inch set....both were about 25.5 to 26 inches tall. The 19s on the rear are about 27.5. I think you are referring to rotational inertia where you account for diameter and mass of the rotating object. In our application you will not be able to feel the braking difference between the 17 and the 18's. Now go to a big set of heavy chrome 22 and that is another story.

I have also had discussions with people who race for a living and they stated that race cars seem to handle better with a stager in width from front to back. 4 of the same size just is not the same. No hard and fast rules on what the ratio should be, but I would guess that GM did their homework on the C6 and the C6Z06. 245-285 and the z is 275-325.

Another subject that I have no real world expierence in is how wide a tire do you actually need. Tires need a certain amount of heat in them to make them work...just read about the AM corvette and that will give you and example. They posted great numbers but they even said if they could have gotten the tires up to temp it would have been better. Most of that is probably the compound they were using and the short runs they were making. On a race track they are probably perfect. I know if you are running a 245 on front and 335 in the rear, you will have a difficult time getting enough heat in the rears without overheating the fronts.

Their are way more qualified people on this forum to discuss this than me...hopefully they will jump in.

If you are going to go with a 9.5 rim in the front you will probably need an 18 inch rim for the added clearance on the tie rods or you will need to put steering stops in the rack.