A serviced car is generally a healthy car.
Servicing your are is one of the most important things you can do for your car's health.
You can see the trend by ever-extending service intervals on certain new cars which in some cases have moved out to 30,000km.
More evidence can be seen in "sealed for life" transmissions and differentials, but a sealed for life engine? Who knows?
Perhaps major car components (engines and transmissions) will become disposable like batteries, tyres, mufflers and shock absorbers. We might one day see cars with engines like cassettes where you run it for a year then take it to a replacement centre which un-clicks the old engine and clicks in a new one.
In the meantime, we still need to take the car regularly to have its vital fluids checked or changed and other electronic and mechanical functions reviewed or adjusted.
Technology in cars like electronic fuel injection and electronic control units certainly have simplified servicing and "tuning" a car if the right computer equipment is used but they have also made the process more involved for the mechanic (technician) who must be trained to a higher level.
There is much more to servicing a modern car than simply giving it a "grease and oil change." The old $35 dollar grease and oil might have passed muster a decade ago but is in most cases insufficient attention for a new car with its many sophisticated systems.
Car servicing can involve up to 50 or more component and system checks and adjustments. And despite complaints about the cost from some car owners, it's worth the money. Maintaining the engine in peak economy, performance and emissions condition requires electronic monitoring and fine adjustment according to the diagnostic computer read out.
A correctly serviced and tuned engine will have a longer, more economical service life than one that is run into the ground with minimal or inappropriate attention. It can also pre-warn or potentially major problems with the engine and transmission.
A full service will include fluid level checks and or changes depending on the system. Hydraulic fluid is hydroscopic (attracts and absorbs water) and should be changed at regular intervals. Water in hydraulic fluid has the potential to corrode the system from the inside with predictable results.
Coolant is another critical fluid to a car's performance and engine longevity. Coolant degrades over time and loses its ability to inhibit corrosion inside the engine and also its cooling efficiency.
A full service will pick up any potential cooling system problem including leaks from the radiator, cap, water pump, cylinder head or gasket and hoses. A full service will also among other things, tell you the condition of the brake pads, battery condition, steering alignment, tyre tread depth, suspension condition, oil leaks of any sort, exhaust leaks or corrosion, even how well the door locks are working.
And the best thing apart from having a fully functional, safe car is that with a complete service history, the car will be worth more when you sell it.