When is a tune up required on a 2006 Toyota Avalon?

A tune-up for a 2006 Toyota Avalon is typically recommended every 30,000 to 100,000 miles, depending on driving conditions and maintenance history. Key indicators that a tune-up is needed include decreased fuel efficiency, rough idling, or difficulty starting the engine. It's also a good time to check and possibly replace spark plugs, air filters, and other components that wear over time. Always refer to the owner's manual for the manufacturer's specific recommendations.