alignment problems
 

I lowered my 93 civic si, i bought all the caster and cameber adjusters from ingals. I was just wondering why i have to keep putting in new lower control arm bushings?? Is this right, would polyurathene bushings really be necessary ow would they evern help! i guess im just asking what do i need to do so i can keep my tires longer than a few months? i have asked around here and done all the reserch but no answers except suggestions about these poly bushings? pls help, 300 dollar set of tires is hurting my landladys pocket book