Bet you didn't know about this gas-saving tip

Every time gas prices rise, consumer reporters reprise the best of the gas-saving tips. Experts are now predicting gas to hit $4 per gallon by May.

I'll mention some of the usual tips in a moment (including tips only for the Twin Cities), but here's one that I haven't written about previously.

Cenex has launched a Tanks of Thanks program that gives free fuel to those who make their communities a little better. Anyone can nominate someone for the award. Winners chosen monthly get a Cenex gift card worth $50.

Here's a winning nomination for Mike Berg of Burnsville, one of the winners in January: "Last November I fell and I had to go into a rehab center for five weeks. While I was in rehab, Mike and his wife Doris went to my house and installed extra railings on the staircases and grab bars in the garage and throughout my house. They also consolidated my living room, so it would be safer for me to move around. Without their help, I would not have been able to come home. I greatly appreciate the giving of their time to help me out. They never asked for anything in return. Good friends are a godsend. Throughout my ordeal I have had a group of nine very good friends that have taken time out of their lives to help me. I thank God for that. I am very fortunate. Thank you."

Cenex gas stations are located in Lino Lakes, Shoreview, Inver Grove Heights, Albertville, Belle Plaine and Northfield. Lino Lakes One Stop, 6501 Ware Rd., 651-765-0512; Shoreview Quick Stop, 5910 Lexington Av., 651-786-5591; Inver Grove Heights Cenex Pump 24, 5500 Cenex Dr., 651-335-4930; Albertville Heidi's Market: 11850 62nd St NE, 763-497-0905; Belle Plaine Cenex Convenience Store: 840 East Main, 952-873-3344 OR 952-873-4244, Northfield Central Valley Co-op, 1480 Bollenbacher Dr., 507-645-7379.

Get nomination forms on the Tanks of Thanks site.

You probably know these tips already, but it doesn't hurt to review them. Most of us have heard about keeping the car tuned up, keeping tire pressure at the recommended maximum, keeping the junk out of your trunk, driving the speed limit, using cruise control, and shutting off your engine if idling for more than a minute. And don't forget about hoofing it or taking public transportation.

Watch the newspaper inserts for cents off coupons at Holiday or other gas stations. Holiday and Super America will match all competitors' coupons. On Tuesdays, SA and Holiday double the coupon amounts.

If you're a Costco member and you use your True Rewards American Express card to pay for gas, you get an additional 3 percent discount in the form of a rebate check mailed in February. The 3 percent rebate is gravy on top of the fact that Costo's prices around the metro are already among the lowest. I used to believe that the 3 percent discount was only good at Costco stations, but it's good at all stations when you use your True Rewards credit card. However, the discount may not be applied at certain stations owned by a retail store, including Cub or Rainbow stations or Fleet Farm. It's because Cub or Fleet Farm may use the retailer code with American Express instead of a service station code, but you can always call Amex to ask if they can recode it for that and future purchases.

Use a site or download the app, both from Twin Cities Gas Prices to find the lowest prices in your area.