Why? New Wheels And Other Question

[BlexusGS]

Just out of curiosity, I purchased new 19" wheels and tires. Why are there more balancing weights on some of the wheels and less on others? The wheels are NOT cheap either!

Also, I got a tranny flush the other day from the dealer. The car seems to vibrate a good amount when in drive (stopped at a light). Why is this? Please help, thanks again guys!

Nick

[PHX ATC]

Tires more often than not come way out of balancing wack. Hence, the weights needed.