We balance a fair amount of wheels/tires here. Two things that I constantly rail about; multiple weights around a rim and tires that are not round. And we see a lot of both. When we buy tires, it is only matched sets of used from the wrecking yards. Any more, I try to order two sets because often as not, one set will have a tire or two or three that are egg shaped. So back they go. For our personal vehicles, I try to only use Michelin Defenders. Great tires. Very little weight needed and they are consistently ROUND!