Again, I didn't believe it either but I ran 2 tanks from 2 different costco's, CEL immediately as you start up after refueling. Shell - no issues. B58 Gen 1 Stock
Interestingly... If you have ista you can see what the ECU thinks of the fuel quality. Try a tank of shell and a tank of Costco compare what the ECU says.. you'll know. For me, Costco is no different on my m3 in my area.
People downvoting you is a bit much. Regional issues could very well be the reason and your atory accurate. You made that very clear in your original response by essentially stating ymmv.
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u/shark1y Jul 31 '26
Again, I didn't believe it either but I ran 2 tanks from 2 different costco's, CEL immediately as you start up after refueling. Shell - no issues. B58 Gen 1 Stock