The high cost of diesel is rippling through corporate supply chains. Walmart said in a memo obtained by the Wall Street Journal that it will begin adding a fuel surcharge on some of its suppliers next month. Amazon imposed a similar fee on sellers who use it for certain fulfillment services in April. The impact is already reaching store shelf prices, and analysts say to expect more of the same. "Essentially, all goods that have to be shipped by trucks are going to be impacted," said Michael E...