(CNN)– $4 gas is holding. AAA says the national average for a gallon of regular gas on Tuesday, July 21, is just over $4. In South Carolina, the average price for gas is $3.70 cents a gallon. That’s up slightly from Monday, July 20, as the U.S. and Iran continue trading strikes. AAA says d iesel is now averaging about $5.14 a gallon, nearly four cents higher in a day’s time. Experts say higher diesel costs can put inflationary pressure on goods moved by semi-trucks across the country. Categories: Local News, National News, News, Politics Tags: Columbia gas prices, gas price, Gas Prices, Iran, Iran Missile Attack, Iran Missile Strikes, Iran War, Oil Prices, President Donald Trump, SC gas prices, South Carolina gas prices, U.S. economy ...read more read less