Originally Posted by M3SQRD
If they did use 18" as the reference diameter on your 19" wheels then, yes, that will have an effect on the wheel balance and/or the amount of balance weight required. The tire/wheel balance machine corrects for static and dynamic unbalance issues - the diameter is important because it defines the "plane separation".
Only you can answer your last question...do you still have wheel unbalance issues and/or steering wheel vibrations with the new balance weights? If the answer is "yes" then take your car back and have them perform the wheel balance correctly...
awesome, thank you for the feedback. Turns out on second attempt, as you suggested, they determined the the alternative front wheel was slightly bent as well. I find it amazing that the car was given a good bill of health when there was still a noticeable issue with the vehicle. The rims have both since been replaced and the car is running perfectly. Nevertheless, I learned something regarding the alignment/balancing measurement...so for that