In my area, Shell is usually the cheapest or tied for cheapest, among the standard gas stations, before discounts. That will simply vary by area. It is true that a Costco, Sam's Club etc will usually be cheaper despite whatever cards you use at Shell, but sometimes, it's not worth the drive. Say your final price at Shell is $2.33 after discount/card rewards and the price at Sam's is $2.29 (realistic numbers in my area). That's 4 cents per gallon savings if you go to Sam's, which is about 20 miles each way. My Jeep gets about 20mpg, so I'd burn about two gallons on the round trip. Two gallons costs roughly $4.60, which means I'd need to buy 115 gallons per trip (obviously impossible) to break even, strictly based on what I am spending on gas (this doesn't take into account my time driving back and forth, or the miles on my vehicle). Long story short, it rarely makes sense to drive any significant distance for a lower price, if that is the only reason you're going. I fill up every time I shop at Sam's, or happen to be near one, but otherwise, mostly stop at Shell for 5 cents + 3%.
The reason Shell comes up in threads like this is that Shell is among the few (maybe the only major brand) with a simple 5-cent rewards card. The others (BP, Exxon etc) tend to involve another kind of points to track and redeem.
The free Shell Fuel Rewards program combined with any 3% or better card works great. If gas goes under $2/gal the card may make sense. I received a mailer for the MC and almost jumped at it until I researched it here. Basically the mailer stated you could get up to 35c/gal by using the card within arious categories. These just happened to be the categories that earn the best on other cards.
If gas does get below $2/gal I will pull the trigger.
The Shell card would be somewhat useful for those non-category months for gas. For me, I won't be using it for April-June since Discover will have 5% off gas during that 2nd quarter. Can't pass up a good 5% cash back on something like that.
