I fill a 16 gallon tank once a week. $6-$7 a week does not seem like a huge amount to me on a personal level though it is $25 - $30 a month I am not spending elsewhere.
Assume this is an average amount per American. 250,000,000 cars on the road, that is over one billion a month not going into other areas of the economy.
Coupled with higher costs of getting goods to market, the price of everything goes up while we have less to spend.
Simply put, if the trends of average summer fuel increases stay the same, by the late summer the economy will be up shit creek without a paddle.