In today’s cars that are computer controlled, the definition of a tune up has really changed. On most cars the only parts that can really be replaced on most cars, are the Spark Plugs, Spark Plug Wires, Fuel Filters, Air Filters and Positive Crankcase Ventilation Valves (PCV Valve). There are not any components that require adjusting, setting or dialing in.

In the old days we had carburetors, points, condensers, distributors with distributor caps & rotors. These all needed replaced and readjusted periodically. In our cars today,
the computer of the vehicle controls the valve timing, ignition timing and fuel delivery. Malfunctions on a vehicle can be camouflaged by the computer, whose function is to keep the engine running as efficiently as possible for as long as possible. It will signal a Service Engine Soon, or Check Engine Light when it detects a problem. But it will try to compensate for that problem at the same time, so the vehicle will still run fairly decent.

On today’s cars it is best to perform tune-ups based on mileage. The vehicle’s manufacturer has mileage based intervals for replacement of these parts and other maintenance services. These are designed to be performed preventatively so that the parts do not fail prior to replacement. Some common mileage intervals and maintenance recommended is as follows:

Every 3,000 miles:

  • Replace oil
  • Replace oil filter
  • Inspect air filter – replace as needed
  • Check and top off all fluids
  • Check tire pressure (fill as needed)

Every 7,500 miles:

  • Replace wiper blades

Every 15,000 miles:

  • Replace fuel filter
  • Replace cabin air filter

Every 30,000 miles:

  • Replace automatic transmission fluid
  • Replace automatic transmission filter
  • Flush cooling system
  • Replace pcv valve (recommend whenever spark plug replacement interval is)
  • Replace spark plugs (vehicles with non platinum spark plugs)
  • Fuel Injection and Carbon Clean Service

Every 50,000 miles:

  • Replace fluids for:
    • Differentials
    • Manual transmission
    • Transfer case
    • Power steering
    • Brakes

Every 60,000 miles:

  • Replace pcv valve
  • Replace spark plugs (this includes vehicles equipped with platinum spark plugs)
  • Replace spark plug wires
  • Replace timing belt (this varies per manufacturers specifications on your vehicle)

The consequences of waiting for parts to fail can be, lack of performance, loss of gas mileage, hard starting issues and etc. For example, if the tune up parts, like the spark plugs get completely worn it can cause the vehicle to misfire and can also cause a hard starting issue. These conditions can cause damage to the exhaust system of the vehicle. If your vehicle has an inline fuel filter it can get plugged over time and can cause fuel pump failure.

So, we recommend following your manufacturer’s specifications on tune-ups and other maintenance, based on mileage intervals. This will help to maintain a new vehicle’s warranty and also add longevity to the life of your vehicle. If you have any questions or comments feel free to contact us at [email protected] or write at 139 NW 2nd St. Gresham, OR 97030.

Steve and Karen Johnston are owners of All About Automotive, providing auto repair and auto maintenance in Historic Downtown Gresham. If you have questions or comments, call them at 503-465-2926 or email them at [email protected], you can also visit our website at

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