When Costco came to Albany, Or. and started selling gasoline, the prices all over town dropped by 10 to 15¢ per gallon to compete with Costco's prices. There could be more profit tacked onto diesel, so the price difference could be more. I think that if all us TDR people and others request that Costco carry diesel, and enough people request it, and Costco complies, we may be able to lower the price of diesel over most of the country. Wouldn't hurt to pass this on to other diesel truck and rv forums either.