stallion8797

Is it better to use the largest rims, diameter wise, possible or to use something just big enough.

For example: If my car has 18 on front and 19 on back, do I keep this or go to 18 all around? Drop to 17? Go to 19?

AU N EGL

Drop to 17 vs go bigger to 19.

17" tires are much less expensive then 19" tires. However, if you have 18" on front why not just go to 18" on the rear as well. 18" all around.

19" are just larger enough that the added wt is noticeable in acceleration and braking, even over 18"s

stallion8797

I was thinking of going all 18" but is there a noticeable benefit to dropping to 17"?

AU N EGL

What are you going to use your car for?

Smaller wheels rotate quicker. Wt is closer to the hub.

Speed will read faster then it is with 17"

95jersey

The 18"s will give you a lower profile tire which will result in better turn in, but 17" rubber is slightly cheaper

Jim 47

Hummmm , well could be IF the tire's rotating diameter is less on the 17" wheel.

The rotating diameter is usually available for various sizes of 17", 18" and 19" (mounted) tires. The TIRES with the smaller diameters will turn more times per mile than the tires with the larger diameters, independent of the diameter of the wheel.

The smaller wheels will also set the car closer to the road than a larger diameter wheel, and will provide a shorter lever arm to the center of gravity of the car's mass, which should translate into less lift of the car's mass during strong cornering forces.

For tire availability, lower cost of wheels and tires, lower stance of the car, and a very small atvantage in the side to side weight transfer during hard cornereing, the 17" wheels should be the best choice.

Jim Helm

stallion8797

I'm looking to focus on HPDE with drag racing on occasion.

I will keep the overall diameter the same regardless of rim size. I currently run 255/35/19 in the rear and 235/40/18 in the front.

BrianCunningham

I've got 18's in the front 17's out back.

The 18's help the turn in, the 17's give me a little more sidewall to help put the power down.

NASAblue

brake size might be a consideration to necisitate 18's

Rotational moment of inertia increases dramatically with larger wheels causing less rotational efficiency weather trying to increase or decrease speed.