Fribblehead,

I used to work at Sam's Club and every year the state of Illinois Weights and Measures department would test our pumps. It turns out they take all that gas and test it for octane level. He told me that Shell hands down sells the best gas. The actual octane levels are consistently 3-4 points higher than advertised. So if you are buying 87 octane at Shell, you are actually getting 90 to 91. He also told me that no name gas is usually as advertised. Hope this helps.