In my experience I have always felt and found that on a road car that if/when you switch out the stock wheels with lighter aftermarket ones you drop rotational mass which allows your car to among other things accelerate faster once the tires grip, but at the cost of allowing your car to spin said tires easier.

However, recently on another forum another member has somewhat debated this stating that you will get more traction if you switch to lighter wheels.
His philosophy is that the suspension works better with the lighter wheels and keeps the tires to the ground better and "increases" the contact patch of the tire for improved traction.

In short, he's said lighter weight wheels will not allow your car to spin the tires easier.

Personally, I don't see how his philosopy could possibly be true.
With less weight to turn but the exact same tire on the road, how could the engine NOT turn the lighter rotational mass quicker and easier than with heavy wheels.

So what's your guys thoughts and experience on this:
Will lighter wheels with the exact same tires give you more traction or in a sense less because you will spin your tires easier due to the decreased rotational mass?

 

bump

 

I'm going to say that it is easier for the car to loose traction...you are loosing pounds of unsprung weight, which is going to be a dramatic difference in acceleration. The car will handle much better since it wont have as much weight to move around, but im going to say that since you will have a better weight to power ratio that the car will loose traction easier.

-Sean

 

i'm gonna say more traction
it all comes down to tires too

if you compare a 15lb rim to a 20lb all else being equal the lighter rim will be faster

the lighter rim will always be better especially @ the track

i've read a sports compact car article about this:

every pound of unsprung weight(everything not held up by suspension) equals to about 1.4 pounds on the chasis