The website GasBuddy.com went through a ton of data to find the best and worst days of the week to buy gas in all 50 states including here in Iowa. If you follow their advice, they say the average driver can save about $30 a year, which adds up if you factor in multiple years of savings. And that's just the average. If you drive a lot, you'd save more.

Here's what they found for us here in Iowa:

  • The BEST day to buy gas is TUESDAY.
  • The WORST day is FRIDAY.

In general, the best days to buy gas nationwide are Monday and Tuesday because they usually bump the prices up in the afternoon.

The worst day to buy gas is Friday, because that's when gas stations bump their prices up to make more money off people leaving town for the weekend.

The study also found that Friday around 5:00 pm. is the busiest time for gas stations.

(Read more from the study in USATODAY)