The fuel economy cost of having one or more tires out of balance is hard to
estimate, as it depends on the degree of imbalance and the type of driving.
However, because the vehicle now has to overcome a vibration component as well
as rolling resistance, there is clearly a fuel economy penalty.
There is also a vehicle maintenance issue. At highway speeds, a typical passenger
tire rotates at 14 times per second. Out-of-balance tramping and shimmying will
shorten the life of other suspension components and will produce uneven tire wear.
Out-of-balance tires can exhibit ìcupping,î a wear pattern that looks like a series of
bald spots around the tireís circumference.