Bigger tires?

[jmwilso2]

Hi Jack thanks for the reply. From an aerodynamic stand point I cant see the slight increase in frontal area being a major significance. My thinking being that if the tire is say 2-3 inches larger in diameter, half of that increase will be inside the wheel well and thus not part of the frontal area. This means that each tire will have an extra 8-12 square inches of frontal area. If this was the case on a vehicle that is already highly aerodynamic I could see it being a significant factor but not so much on a super draggy truck. As for the interference drag change that is a really interesting point I had not given any thought to. I agree it probably wont decrease it. I cant really see it increasing it either though. But as with the frontal area issue I think the change would be too small to notice. Its the increase in engine load that really has my attention. Your point that the engineers at Ford chose the diameter of the tires, the rear axel ratio and tranny gearing to match up with the power output of the engine to give maximum drivability and economy is exactly what has my curiosity. With the mods and gryphon in my truck I should be getting a bit of extra power to the rear end so would this throw the engineers balance out of whack, and would a slightly larger tire restore the equalibrium. I am at a loss but I have lots of time to figure it out before I need to replace them. I may just go out on a limb and try it to see what happens. But I'd like to get as many opinions as possible first.

Thanks for the input

Joe