We recently participated in the USAC D1 midgets series at Columbus Motor Speedway (pavement). Here is the tire bill for that race:
MG7 $159.06
MG5 $168.93
MG7.3 $187.55
Tax $34.80
Total $550.34
We actually bought four new tires but returned the fourth one when we encountered steering issues.
It's my understanding that these tires cannot be used for a National midget race.
ASAIK, there was no limit as to the number of tires that could be used to race for the evening.
