The 1st generation Toyota Tacoma with the 3.4L V6 (5VZ-FE engine) has six twin ground electrode spark plugs. Toyota recommends that these spark plugs be replaced every 30,000 miles, however there are many accounts of 5VZ-FE owners who have driven on the same set of spark plugs for double and triple that mileage. I personally wouldn’t let it go to 90,000 miles, but I also wouldn’t necessarily follow the 30k-mile change interval either. My parents’ Tacoma is about 15 years old with only 30k miles on the clock, so we decided to replace the spark plugs more so due to the age rather than the mileage interval.