AI-generated · grounded in NHTSA data

Reliability & 5-year cost of ownership — 2008 Gmc Sierra Denali

Overall rating NHTSA-grounded

Average

Estimated 5-year repair + maintenance cost: $7,000–$12,000

The 2008 GMC Sierra Denali has a moderate number of complaints, mainly concerning the structure and airbags. No widespread severe issues are evident, resulting in an average reliability outlook.

Most-common failures

Part Typical mileage Cost range Frequency
structure90,000–120,000 miles$300–$600common
airbags70,000–100,000 miles$400–$900occasional
electrical system80,000–110,000 miles$200–$500occasional

Scheduled maintenance to budget

Routine items every owner should plan for.

  • oil and filter change
  • brake system check
  • tire rotation and alignment
  • engine air filter replacement
  • coolant system flush
  • spark plug replacement
  • transmission fluid check

Warning signs to watch for

Symptoms that signal a major upcoming repair.

  • cracking noises in structure
  • airbag light on
  • flickering electrical components
  • unresponsive locks
  • soft brake pedal

Generated by gpt-4o on 8/22/2026. Cost ranges are conservative estimates that account for typical regional variation.