i currently have a set of 16" wheels that weigh in at 23lbs each. (i know stupid me) with 205/45/16 tires. i would obviously like to get somthing lighter perferably in 16" as well.

but what if i were to get a 17" wheel that was 18-19lbs with 205/40/17 tires......would the increase in tire size and lighter weigh affect the acceleration much? even though i'm increasing the tire size i'm shaving 4-5lbs per wheel so it should be an improvment right?

 

 

The further the contact surface is from the hub the more torque needed to spin the wheel.

 

it would depend on the weight of the tires relative to the weight of the wheel, and the design of the wheel itself (i.e. how much mass does it have at it's center and it's perimeter. if all those factors were equal, the moment of inertia of a cylindrical object is proportional to the square of it's radius. so a 23 pound wheel of r=8" has the same moment of inertia as a 20.4 pound wheel of r=8.5"

are the weights of those two tire sizes the same??