A lot of confusion exists about the difference between a minor and major tune-up, what it entails and what types of parts are included with each. In short, a minor tune-up is usually needed around every 30,000 miles or so, or depending upon the vehicle owner's preference. A major tune-up can be performed at intervals of 60,000 or 90,000 miles, depending upon the vehicle brand and type of engine. Marked differences exist between the two types of tune-ups.
Minor Tuneup --- Electrical
The electrical components replaced in a minor tune-up usually consist of spark plugs only. The new spark plugs are gapped to manufacturer's specifications and installed in the vehicle. As a rudimentary inspection, the mechanic will check the timing, and make visual inspections of the air filter, cap, rotor and plug wires. Depending upon the shop practice, older vehicles might receive the installation of points and condenser as part of a minor tune-up. Some manufactures claim that their vehicles do not require a spark plug change until after 100,000 miles.
Minor Tuneup --- Oil, Grease and Fluids
An oil change (with filter), on rare occasions, can be added to a minor tune-up, as well as a suspension lubrication. If the minor tune-up falls within a period of time that permits an oil change, filter change and lubrication, then it can be included on the service ticket. Ordinarily, vehicles receive oil changes as frequently as every 3,000 to 10,000 miles, and many vehicle owners perform their own oil and filter changes. All fluid levels, including transmission, power steering, radiator and brake fluids receive visual checks, and get a topping-off if the reservoir requires less than a quart.
Major Tuneup --- Electrical
A major tune-up for electrical components consists of the replacement of all spark plugs, spark plug wires, distributor cap, rotor, and points and condenser, if applicable for an older vehicle. The mechanic will check the timing and adjust it to specifications. Sometimes a voltage check is performed on the charging system, as well as a battery check for proper electrolyte level. All electrical vacuum switching valves and electrical sensors receive a visual inspection.
Major Tuneup --- Fuel Systems
Fuel systems in a major tune-up include the changing of the main fuel filter, and sometimes the in-line carburettor fuel filter or screen. The mechanic will adjust a carburettor-type vehicle, setting the idle mixture screws, idle speed, fast idle or choke. Some repair facilities add a fuel system cleaning for fuel injected-engines, which most often entails an additive.
Major Tuneup --- Oil, Grease and Fluids
A major tune up will include an oil and filter change, as well as a complete suspension and drive line grease lubrication. A mechanic will check the CV (constant velocity) joint boots and other suspension components. The rear-end differential oil will be checked and filled to capacity, as well as any gear oil needed for a manual transmission. Another fluid might involve the windshield washer soap and water. The difference in the major versus the minor tune-up, as far as fluids, will be that the cost of fluid additions in the major tune-up will be absorbed into the cost.
Major Tuneup Optional Services
Some optional services occur when the repair facility includes them in their major tune-up. Not all repair facilities include extra service procedures. Some major tune-up additions you might see will be the checking and filling of tires, a brake inspection and brake adjustment. A solid lifter valve adjustment will most likely appear on a major tune-up ticket, since it is acknowledged as a major tune-up item. There could be a shop that charges extra for a valve adjustment, depending upon the model and complexity of the job.