How often do you change spark plugs on a 2001 Toyota Highlander?

For a 2001 Toyota Highlander, it's generally recommended to change the spark plugs every 30,000 to 100,000 miles, depending on the type of spark plugs used. If you're using standard copper spark plugs, aim for around 30,000 miles, while iridium or platinum plugs can last up to 100,000 miles. Always consult your owner’s manual for specific recommendations related to your vehicle's engine type and driving conditions. Regular maintenance checks can help determine the optimal replacement interval.