I have 100,000 mile spark plugs in my car. When will I need a tune-up?
In the traditional sense there is no such thing as a tune-up anymore. Carburetors and distributors with their myriad of parts destined to failure have been replaced with electronic injectors and electronic ignition systems. There is virtually little to wear out. Aging Ignition wires and spark plugs may continue to function for 100,000 miles but not optimally. The car manufacturer’s boastful claim of 100,000 between tune-ups has little grounding in common sense, and is mostly a marketing ploy. At the price of gasoline these days even a three percent decrease in fuel efficiency is expensive, not to mention ecologically unfriendly. A fresh set of spark plugs any time over 50,000 miles will normally make a noticeable difference.