2015 Buick Regal Owner Manual - Page 347

11-6 Service and Maintenance (2) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. (3) Or every four years, whichever comes first. (4) Or every five years, whichever comes first. See Cooling System on page 10-18. (5) Or every 10 years, whichever comes first. Inspect for fraying, excessive cracking, or damage; replace, if needed. (6) Or every three years, whichever comes first. Footnotes - Maintenance Schedule Additional Required Services - Normal (1) Or every two years, whichever comes first. More frequent replacement may be needed if the vehicle is driven in areas with heavy traffic, areas with poor air quality, or areas with high dust levels. Replacement may also be needed if there is a reduction in air flow, excessive window fogging, or odors.