what is the reason to do tune up?

[dealcatcher]

what is the reason to do tune up?

Since most of the jobs are done by visual checking, why not just do an oil change instead?

[Jucius Maximus]

Because "tune up" has a higher profit margin.

(Not that your car doesn't need maintenance, good fluid levels, etc. But "tune up" is a very general thing and they could be charging you to do things that are not necessary at this time.)

[l69norm]

what is the reason to do tune up? Since most of the jobs are done by visual checking, why not just do an oil change instead?

To replace all the things that eventually wear out. Check in your cars owner's manual as to what needs to be replaced and when - typically at 100,000 - 160,000 km mark (i.e. spark plugs, air filters, wires, rotor, etc..)

[Pete_Coach]

what is the reason to do tune up?

Since most of the jobs are done by visual checking, why not just do an oil change instead?
I do not know what you think a "tune up" is.
In it's basic form, it is checking the engine, to make sure it is operating within specifications and replacing wear items. It is ensuring the engine is getting the proper air, the proper spark, at the proper time the proper fuel thereby replacing all the things that may hinder it's optimum operation.
A visual inspection of the car itself is a maintenance item to check the remainder of the car for conformity and safety and is periodically scheduled by the manufacturer.

[Tommy74]

what is the reason to do tune up?

Since most of the jobs are done by visual checking, why not just do an oil change instead?

Cars need tune up, but you might need a check up. But instead of visual checking, why not just do a head swap instead?

[TT333]

Like your attitude OP,

"Car needs a new turbo, I'm afraid"

"Naahhhh just change the oil instead!"

I should have listened to you!