5 Tips to Find the Cheapest Gas Prices Yahoo ^ | Feb. 17, 2012 | Jeff Macke 1. Track Prices Via Websites and Mobile Apps.. 2. Inconvenience Yourself.. 3. Fill Up at the Right Time... Urban legend says gas prices are lowest during hours when most folks are sleeping, from midnight to 5am. Laskoski debunks that myth, but says there is a best time to fill-up that most people wouldn't think of: Wednesday. Gas prices are highest on weekends when the most people are out on the road. Filling up in the middle of the week saves you both sleep and money. 4. Mind the Fine Print on Your Credit Card & Reward Programs.. 5. Get Out of the Car (Opt for Self-Service)..