What car maintenance is really necessary?

Tune-up? Service? Maintenance? What does it all mean?

The quick answer is it depends.

We put together a helpful, basic service interval guide if you’re more interested in when you should do what. If you’re more interested in what the service items are and why you might want to do them, read on.

There is no standard

The software developer who wrote our shop software had a quote in his email signature – “Standards are like toothbrushes. Everyone agrees they are necessary, but nobody wants to use yours”.

There is no industry standard for service packages, even at dealerships. This means that a tune-up from your gas station mechanic will mean something different than the tune-up at a dealership, which is different than the tune-up at a competing dealership down the road. Likewise, a “K-service” like the 30k, or 75k will also be different. There is no governing law that requires a 30k service to conform to vehicle manufacturer minimum requirements, even for the same manufacturers’ dealership service stations. Speaking of tune-up…

There is no such thing as an industry-understood “tune-up.” This misconception has been widespread for years and we have written a dedicated article to further explain things. You can read more about the “tune-up” by clicking here.

Every manufacturer and every vehicle have different service schedules. Take brake fluid service, for example: every manufacturer has a different idea for the same chemical! Honda recommends changing the fluid every 3 years, regardless of mileage. Some Nissan vehicles require brake fluid changes every 15,000 miles. Subaru tends to recommend brake fluid change every 30,000 miles. Toyota never once mentions a service interval for brake fluid, relying instead on service inspection results on a case-by-case basis. Is this because the implementation of braking systems is dramatically different on each manufacturer? No. It has to do with marketing and reducing the perceived cost of scheduled maintenance.

What should a car owner do?

What should you do as a consumer? Some folks elect to do everything the dealerships tell them to do, thinking that more service is better. Others rely on Jiffy Lube inspections to provide recommendations for service. Some drivers do absolutely no maintenance, and only repair vehicles when they break down and are towed to the shop. Some customers are leasing their vehicle and have no concern for how the car will perform for the future owner. There is no hard and fast rule as to the best method of servicing a vehicle; however, at Art’s Automotive we find that the customers who perform preventive periodic services are least likely to experience major component malfunction until very high mileages. We also find zero value in the fuel injector cleaning, engine oil additives, or similar “snake oil” type service up-sells.

Find a shop you trust who can offer you and your car proper service. Since every instance is different, contact us to discuss you and your car’s individual service needs.

Ever wonder what it is exactly that you’re paying all that money for? Here are some maintenance services defined:

Ignition System Maintenance

The ignition system is responsible for generating and delivering spark to the combustion chamber. It has parts like spark plugs, distributor caps, distributor rotors, ignition wires, ignition coils, and igniters. While some of these parts wear down and can benefit from replacement, they account for a small portion of a vehicle’s overall service needs. Furthermore, modern cars do not even have distributors, and their spark plugs may even last 100,000+ miles! If an ignition part fails, nothing sparks the combustion event, and the car will run poorly. In the worst case, an ignition problem left unaddressed may damage the catalytic converter. When you compare this to the damage that might be caused by not adjusting the valves (engine damage), or neglecting the transmission fluid (transmission damage), the “tune-up” takes a step down on the maintenance list.

Motor Oil Maintenance

Changing your oil is important, and the single most simple thing to extend the life of your car. Everyone has his own opinion on how often the oil should be changed, and there is more than one right answer when looking at the bigger picture. Many mechanics say to change the oil every 3,000 miles. Some internet blogs and a few published reports suggest frequent oil changing is a waste of money. Your owner’s manual may have an interval of 7,500 miles, maybe even 10,000 miles! Synthetic oils? Synthetic blends? High-mileage oils? They’re all the same so just buy a $19.95 quick lube? Certainly there must be “the one best” oil change decision available, right?

We have a dedicated page to discuss the oil change, so here are the bullet points:

  1. Do not use synthetic oil to extend the oil change interval
  2. Unchecked loss of oil volume is the primary cause of engine failure
  3. Extended oil change intervals increase internal engine wear, resulting in increased consumption
  4. Extended oil change intervals and subsequent dirty oil condition causes corollary problems (idle, throttle, EGR, etc.)
  5. Service manual “normal” schedules are unrealistic. Adhere to “severe” guideline.
  6. Cheap oil and filter changes can cause problems from defective parts and incompetent labor

Automatic transmission service

Draining and filling the transmission fluid regularly will help sustain the life of the transmission. Automatic transmissions operate by means of friction, which generates heat that necessarily causes chemical wear and deterioration. Poor condition fluid dissipates less heat and can have “abrasive” quality to the internal components.

Transmission fluid condition can be easily judged by its color. New/Good transmission fluid is a bright red color. As the transmission fluid goes bad, it changes in color, first darkening to a dark red, then to a purple, then to a light brown, finally to a dark brown / black color. When a mechanic drains and fills the transmission only a 1/4 to a 1/3 of the fluid can be replaced. This is because, unlike the engine, most of the fluid does not sit in the sump. Instead, it sits in the torque converter, valve body, behind clutch pack pistons, and in many of the passages throughout the transmission.

Replace transmission fluid before it’s bad

Because all the of the transmission fluid is not normally replaced, it’s important to change the fluid as soon as it starts to turn. Otherwise, the bright red color cannot be restored with only one drain and fill. If the transmission fluid does go too long between changes, the transmission fluid can be flushed (all of the fluid is replaced with one visit using a fluid exchange machine).

However, this is much more costly than a drain and fill. It is also explicitly stated by various manufacturers that the procedure is NOT recommended. Forcing the fluid through the system may power wash the “good stuff” out with the bad. We often will only recommend a fluid exchange if transmission fluid condition is so poor that the transmission shifting has already suffered, and it is a last-ditch effort before replacing the entire unit. The best policy is to keep the fluid changes on a regular schedule.

Manual transmission service

Manual transmissions are much simpler than automatics. We recommend replacing the fluid every 30,000 miles because the gear oil will absorb metal particulates from ground synchronizers (admit it, you’ve done it!) and just typical wear-and-tear. Without attention, those metal flakes can accumulate and affect gear mesh surfaces causing internal transmission wear.

Other Gearbox Maintenance

Transfer cases and differentials have the same maintenance requirements as the manual transmission (30,000 mile drain and fill). On trucks with on-demand 4WD, it would not be unreasonable to change the front differential oil and the transfer case oil at 60,000 miles instead of 30,000 miles.

Brake fluid flush / replacement

Until 1994, Acura, Honda, Mazda, and Nissan all recommended flushing the brake fluid every 30,000 miles. Toyota for some reason only recommends fluid changes on a few models. After 1994 many manufacturers dropped the 30,000-mile recommendation for the brake fluid, which is sort of ironic since 1994 is when moisture and grit sensitive ABS (anti-lock brake systems) really started to become common. We believe that brake fluid flushing and ABS system flushing (when the ABS system does not share common fluid) is a service that will save money and provide added brakes system reliability whether the service manual calls for it or not.

Brake fluid is testable with several commercially available systems. We use an electric moisture content meter. Brake fluid’s main weakness is that it absorbs water. When brake fluid is water saturated three things happen: the brake fluid becomes more compressible (a bad quality in a hydraulic fluid), the boiling point decreases (boiling brake fluid can cause a spongy pedal after a long downhill drive), and the moisture in the brake fluid is corrosive to the metal parts in the brake system. The corrosiveness of “wet” brake fluid is in my mind the primary reason for periodic flushing. Especially on cars with ABS. Some ABS modulators cost $2500 just for the part.

Clutch fluid flush / replacement

We recommend flushing the clutch fluid every 30,000 miles. The clutch master and slave cylinders use brake fluid. Moisture will cause corrosion of the clutch hydraulic parts the same as with the brake system, although boiling point and compressibility are not much of a problem as clutch hydraulic pressures and temperature are much lower than those found in the brake system. The reason we recommend the clutch flush more frequently than the brake flush is the system volume is much lower in the clutch system and the fluid seems to become saturated more quickly.


This is a very important part of a maintenance program. Just because the car drives OK does not mean it is OK. Scheduled replacement of parts, oils, and fluids is only one part of avoiding breakdown, the other is routine checking for early signs of trouble. Unfortunately, not all breakdowns can be predicted. Sometimes a part like an igniter might go out unexpectedly, and there would be no way of knowing that it was going to go out ahead of time. There’s nothing that can be done about these types of breakdowns; however, you can substantially reduce your chances of having a breakdown by inspecting those things that can be inspected. As part of all of the 15K interval services (15k/30k/45k/60k etc..) we perform a 131-item inspection looking for any problems and early signs of trouble.

Timing belt replacement

There is a lot to say about timing belt maintenance, so we’ve devoted a whole page to it. Click here to read it.

Air filter replacement

The air filter can be inspected by holding it up to a very bright light (skylight works well) and looking into the creases. When the light cannot be seen evenly across the creases, it’s time to replace the filter. Frequently the air filter will look dirty, but when checked with this method will turn out to be fine. Loose dirt and debris can be removed from the filter by tapping it on a workbench. We always do this check before replacing an air filter. Frequently quick lube shops will sell air filter during an oil change, so we frequently find a clean air filters on cars in for service. We include the air filter on all of the 15K interval services (15k/30k/45/60k etc..) and remove it from the bill whenever we find that it is clean.

Fuel filter replacement

On older carbureted cars, the fuel filters were cheap, and needed to be replaced frequently (every 15,000 miles). Most 1988 and newer cars are fuel injected and have more expensive, longer lasting fuel filters, often mounted in hard-to-reach locations. There is no way to gauge the condition of fuel injection fuel filter other than a fuel volume test, which will only let you know that the fuel filter is restricted, or the fuel pump is bad. This test isn’t much help in determining what to do preventively. In general, we recommend following the manufacturers recommended interval. Many manufacturers stopped using fuel filters starting around 2001 when more cars went to returnless fuel systems. Instead, there is only a strainer screen at the fuel pump inlet in the fuel tank.

Valve Adjustment

If you were only going to do 3 maintenance items and ignore all the others, this would be one of my picks. Not all cars have adjustable valves, but for the ones that do, periodic adjustment is a critical maintenance item. Over time the valve faces and valve seats wear, causing the valve tip to get closer to the rocker arm or cam. Eventually the valve will run out of clearance and will be held open all the time. When the valve is held away from the seat, it will not be able to dissipate the heat from the 2000 deg.+ Combustion chamber environment and the high strength steel will literally melt. This can cost you anywhere between $1200 and $5000, depending on what type of car you own.

Unfortunately, more and more manufacturers are removing the valve adjustment recommendation from their maintenance schedules or increasing the interval to ridiculous levels. For example, Honda 2000 and newer cars have a recommendation of 105,000 miles or “when noisy”. The problem with the mileage is we know for certain that every 105,000 miles is not frequently enough. We had a CRV with a burned valve and a $2500 repair bill at 45,000 miles. The problem with “when noisy” is that only loose valves make noise. When valves are tight, they do not make noise. Tight valves are what cause engine damage. Toyota used to have a recommendation of 60,000 miles for their shim-type engines, which I think was wise. Now their recommendation is to adjust the valves “when noisy” or “when the engine is running rough”.

“When noisy” isn’t adequate for valve adjustment

You already know the problem with the “when noisy” recommendation. The problem with “when the engine is running rough” is that with every second the engine is running rough because of a tight valve, that valve is becoming more and more damaged. My opinion is that the manufacturers are sacrificing “after-warranty” longevity by reducing recommended maintenance. My guess is that they are doing this to reduce the perceived Total Cost of Ownership, making their product more attractive for rental and fleet and other bulk buyers.