Question:How often does my engine need a tune-up?
Answer:Most vehicles made since the early 1980s require
a "tune-up" only once every 30,000 miles. Some of today's
new cars and trucks don't need a tune-up for 100,000 miles!
Actually, there's no such thing as a "tune-up" anymore.
It's really preventative maintenance and involves changing the
spark plugs, air and fuel filters, PCV valve, and checking engine
performance.
Webster's Dictionary defines a tune-up as "an adjustment
to assure efficient functioning." Back in the early 1970s
when many cars still had point ignition systems, checking and
adjusting the points and ignition timing every 12,000 to 15,000
miles was usually necessary to compensate for wear. Fiddling
with the carburetor idle speed and idle mixture adjustments was
also part of the job. Every engine back then also ran on leaded
gasoline, which meant the spark plugs rarely lasted more than
12,000 to 15,000 miles before they became fouled with lead deposits.
So annual tune-ups were an established ritual. Put off getting
one too long and fuel economy, emissions and performance would
all suffer. Getting a tune-up usually restored engine performance
and was often credited for being a "cure-all" for what
ailed your engine. Not so anymore.
The arrival of electronic ignition systems eliminated wear
and the need for any type of periodic adjustment. Once set, ignition
timing would remain unchanged unless something failed (in which
case the engine usually wouldn't run). "Anti-tamper"
carburetors with sealed adjustment screws eliminated the need
for most adjustments. The switch to unleaded gasoline stretched
plug life to 30,000 miles or more, so the annual "tune-up"
became a thing of the past.
Today, virtually everything from idle speed to ignition timing
is computer controlled. Since there's nothing left to "tune"
in the traditional sense, all that's required is to replace the
spark plugs, filters and other wear items periodically to keep
the engine in good running condition.
WHAT IS A TUNE-UP TODAY?
The public still associates the word "tune-up" with
engine maintenance, so most service facilities continue to use
the word in their advertising and promotions. What a "tune-up"
actually includes, however, may run the gambit from replacing
the spark plugs to a thorough engine diagnosis that also includes
scanning the computer system for fault codes, checking engine
compression and dozens of other items that may need replacing
due to wear. In states where annual emission inspections are
required, a tailpipe emissions check may also be included.
According to a consumer survey conducted by the Tune-Up Manufacturer's
Institute, here's what people think a tune-up should include:
- New spark plugs (87%)
- Oil change (34%)
- New air filter (32%)
- New ignition wires (19%)
- Timing adjustment (16%)
- New fuel filter (14%)
- New PCV valve ( 7%)
- New distributor cap ( 5%)
- New rotor ( 4%)
So what do you usually get? Here's the list of items professional
mechanics say are usually included in a tune-up:
- Spark plugs (91%)
- Fuel filter (64%)
- Air filter (59%)
- Rotor (41%) if needed
- PCV valve (37%)
- Distributor cap (31%) if needed
- Ignition wires (28%) if needed
- Check timing (24%) adjust only if needed
- Carburetor adjustment(20%) only if needed
- Oil change (10%)
- Engine analysis ( 6%)
One difference between these two lists that's worth noting
is that many consumers think an oil change is part of a tune-up,
not a separate maintenance service. Maybe that's why people don't
change their oil often enough.
