How Often Should You Change Spark Plugs?
Determining how often to change a spark plug on a vehicle involves several factors. Checking the owner’s manual will reveal the recommended plug change interval. Driving conditions and overall mechanical shape will impact recommended spark plug service, too.
Poor Plug Symptoms
If you detect performance problems like slow pickup or poor gas mileage, check your spark plugs as a possible cause. Replace them if you find evidence of damage to the insulator (body near the head) and the electrode (metal points that form the “gap”).
Engine Problems Caused by Defective Plugs
· Starting defect
· Misfiring when idling
· Misfiring during normal running
· Misfiring only when running at high speed or when accelerating suddenly
· Loss of power when running at high speed or under high load Piston breakdown
· Trouble other than with the engine
How long do automotive spark plugs last?
Spark plugs have an important task to perform in your engine. They produce an electrical spark that ignites the mixture of fuel and air in you engine’s combustion chambers, causing the pistons to move up and down. This movement of pistons is what ultimately gets your car’s wheels moving, so this little spark is a critical part of the whole process; it initiates the combustion in your internal combustion engine.
But like many parts of your engine, spark plugs won’t last forever. Every time they fire, the spark removes some of the metal on the plugs, increasing the voltage necessary to fire the next time.
Besides age, many other things can cause your spark plugs to wear out. They’re subjected to a number of forces inside the engine, including heat, gasoline and oil that can reduce their effectiveness. High performance engines and engines that rev to high RPMs also tend to wear out quicker.
For all of these reasons, it’s important to replace your spark plugs from time to time. Fortunately, high-quality spark plugs should last tens of thousands of kilometers, so replacing them is not something you’ll have to do often. Even if you don’t put many miles on your vehicle, it’s something that should be done at least every few years.
So how long do they typically last? Well, standard copper plugs are said to last anywhere from 10,000 to 20,000 miles (16,093 to 32,187 kilometers), while more expensive iridium or platinum spark plugs can last 60,000 miles (96,561 kilometers) or more [source: Spark plugs UK]. Some high-end iridium plugs are advertised to go more than 120,000 miles (193,121 kilometers), but there’s no actual guarantee they’ll be able to achieve this [source: AA1Car].
If you’re not keeping track of your spark plugs’ mileage, there are several symptoms to look for that can tell you it’s time to have them replaced. If the engine has trouble starting, is rough at idle, stalls, or experiences a drop in fuel economy it may be time to have the plugs looked at by a mechanic. It’s often easy to tell just from looking at the plugs whether they’re worn out or not.
Spark Plugs Have Improved
Spark plug and vehicle technologies have come a long way. Some cars in the 1950s had a recommended interval of 5,000 miles for changing the plugs. Today, through advancements in design and materials, some cars can meet or exceed 100,000 miles without a change. A 4-cylinder 2009 Hyundai Accent has its first recommended spark plug change at 30,000 miles for both normal and severe conditions. Likewise, a 4-cylinder 1990 Honda Accord recommends a plug change every 30,000 miles or two years.
“Long-Life” Plugs
Several manufacturers advertise “long life” spark plugs. Using precious metals such as silver, platinum, gold and iridium, these plugs have an advertised life close to 100,000 miles. An 8-cylinder 2010 Hyundai Genesis has a recommended plug change interval of 97,500 miles, driving in normal conditions, using iridium-coated plugs.
Fix Vehicle Problems to Extend Plug Life
Various mechanical conditions contribute to quicker spark plug wear. The piston rings may wear out, letting oil seep in and foul plugs. The distributor and ignition wires may wear out, resulting in less electrical power delivered to the plugs. DodgeRam.info displays a list of spark plug damages and their likely causes. Correct the deficiencies and you can likely increase your plug life to the miles recommended in the owner’s manual.
With continuous development of new technology for vehicles and plugs, spark plug lives will keep increasing. Removing and checking the plugs yourself can give you valuable clues on when they need replacement. Changing the plugs when needed is a cheap investment for keeping your car running strong.