Flow, keep it simple, you just gave an old guy me, :lol: a head ache and most of the forum members went to sleep. :laugh: We should have a seperate thread for this discussion.Only 19lb, ouch ! This means if I'm applying the ratio of weight added for a rotating unsprung mass which is near 1:7 in general, this means that my extra 23lb per wheel (the exact weight of my wheel is 42lb) feels like an extra 161lb per wheel, that like 4 extra passagers sitting in my car ^^
.... since F = ma
m is a fixed variable on this example, on the 15inch wheel F greater by a very little difference than the 18inch but that's due to the tire used
If we have two rims which their weight is the same thing but their diameter isn't the same, for example, a 195/65R15 and 255/35R18, they have the same diameter of 25", no change in acceleration potential
The difference between the 18inch and the 15 inch, the 18inch have a wider contact point on the ground so a better traction, but lower sidewall (profile) making the ride less comfortable
My conclusion, it's possible to use bigger wheel if it weight the same and have the same rolling radius than the smaller one. Unfortunately, bigger wheel are often heavier than smaller one increasing the inertia and making acceleration a bit slower and affecting handling since it's unsprung mass added to the car, but wider tire allow more traction on the ground
IMHO All things being equal, Wider Tires do not allow more traction on the ground (it is mostly a functioning of the tire compound used), the size of the contact patch is approximately the same for both but the shape of the contact patch changes based on the cross sectional width of the tire/wheel. A skinny tire will have contact patch elongated in the direction of travel (great for accelerating) while a wider tire will have a contact patch not as long in the direction of travel but wider laterally (great for supporting lateral cornering forces).
Drag cars tires are designed to give traction when they spin up the tire diameter increases and the tire gets skinnier, so contact patch is elongated and in the direction of travel to get the best traction. At the drag strip you will see people use slick tires, which can be wide but the tire compound and sticky surface area is what is key.