Why do cars and trucks need tune ups after a certain amount of mileage? And what involves a tune up?

Well first off you have to think...there is actually an explosion going off inside your engine. It might sound odd at first but in a 4 cycle engine i.e. Intake Compression Combustion and Exhaust the fuel is taken inside the engine blown up and pushed out. This quick explosion causes wear over time. Fuel carbons build up and and small parts (spark plugs) wear out. Because cars are more complex with Fuel injection and electronic throttle bodies your car/truck's tune up from a shop ONLY changes the Spark Plugs. They will offer better service at a higher price... You should change your air filter, ignition wires, distributor cap and rotor button (if equipped) and your PCV valve. Sounds confusing huh? Well if you have any other questions you should always consult your owners manual for the manufactures recommendations. They don't leave anything out. Neither should you.

The word Tune Up is a generic term, a tune up may include many different items that are replaced or serviced.

These recommended items will vary between repair shops, makes and models etc.

Spark plug replacement is almost always included, but could include fuel system services such as injector flushes, filter replacements etc.

The reason of course is because over time and mileage, spark plugs wear out and no longer perform at optimized rates.

Same with filters, dirt and trash build up and restrict the flow of air or fuel reducing their efficiency which normally will reduce fuel mileage and cause problems such as hard to start, extended crank times etc.

Parts don't last for ever and need replaced at the recommended mileage and or time.

Jerry Christopher

http://www.usedcarwise.com/

there is a wear and tear on your engine . your spark plugs and wires get burned out and need to be replaced. mainly a tune up is involing spark plugs an there wires oil change and fluids in the engine . like a human body out with the bad in with the good.

part also as well as what has been mentioned to you is that tappets need to be adjusted after a time they need to be rechecked for maximum performance as valves need to open at the rite time with the rest of the engine which also give better fuel econamy saves you money get it done or do it yourself trouble with most cars nowadays they got to be hooked up to a poxy computer not like the old days lol