A major gasoline retailer in Minnesota is ending an enticing promotion — doubling its own and competitors’ cents-off-per-gallon coupons on Tuesdays — that it has offered for more than five years.

Tags have been placed on SuperAmerica pumps alerting customers to the offer’s demise as of the end of August. That leaves just two more Tuesdays, Aug. 23 and 30, for motorists to take advantage of the promotion, which began in May 2011.

SuperAmerica will continue to accept competitors’ coupons for their face value.

“We weren’t seeing the results that we needed,” said Gary Hanson, a spokesman for Arizona-based Western Refining, which owns nearly 170 SuperAmerica outlets in Minnesota and Wisconsin and has franchise arrangements with another 100-plus.

“It’s just part of the regular analysis of our business,” Hanson added. “It went its course, and it was time for us to make a change.”

In place of double the coupon’s value, SuperAmerica will double the number of points earned when buying gasoline on Tuesdays. The points are redeemable for discounts on gasoline or other purchases.

With gasoline so inexpensive of late, a doubled coupon has been shaving a larger percentage off the pump price than when the promotion first started.

These days, a gallon of 87 octane at SuperAmericas in the Twin Cities can be had for a little more than $2. That price was above $4 a gallon in the spring of 2012.