Sometimes I purchase mechanical parts that are specific to my cars from Advance. Many times you can put them in your "cart", not act on them right away, and then get an email from Advance offering a 20 or 25% discount, which I will then take advantage of. Sometimes I find that even with Advance's 25% off, it's not cheaper than purchasing elsewhere. This week I wanted to buy some bottles of Zinc additive to have on hand for oil changes. Advance had them for $10 a bottle, and I was offered the 25% discount which would bring it to $7.50 a bottle. Before making the purchase I checked to see if Walmart carried it -- and they did for $5.84 a bottle. So the moral of the story, watch out for those Advance Auto discounts.