Shares of AutoZone Inc. (NYSE: AZO) were down 8.5% as of 12:30 p.m. EDT on Tuesday after the automotive parts retailer announced disappointing fiscal third-quarter 2017 results.Quarterly revenue climbed 1% year over year to $2.62 billion, and diluted earnings per share rose 6.2% to $11.44. Adjusted for AutoZone's adoption of a new accounting standard late last year, earnings would have increased 3.2%.