Heres my opinion...as a metal fabricator...
When it comes to steel vs aluminum in any structural
suspension compontent, the idea that comes to mind is weight.
However, for the aluminum arms to be as strong as the steel ones, much thicker aluminum must be used... I would ask the manufacturer what the arms weigh...and the thickness and alloy of the material used.
A steel arm made from 1.75" DOM steel tubing might have 1/8" thick walls... the similar strength aluminum arms would be the same diameter, but most likely 2-3 times the wall thickness..
what im trying to get at is, with smaller components, the weigh difference between steel and aluminum(when they both have to meet the same strength req) is usually very minimal. And IMO not worth the $.
If its something large where the weight of the aluminum one is 60% or less than the steel one, i say its definatley worth it.
I doubt your talking about more than .5lb savings on the
control arms. Id save your money and put it towards motor,
suspension and brakes. Then when you cant get the car to go any faster, handle any better, or stop any faster; then you start worrying about lightening the car...
youve gotta be pretty serious for that
dc