Spark Plug Replacement Cost
Plug type matters as much as engine size. Here is what you will actually pay.
Quick answer
4-cylinder: $80 to $300 | V6: $120 to $400 | V8: $160 to $500
Higher end = iridium plugs + buried install. Lower end = copper + easy access.
Spark Plug Replacement Cost Estimator
Get a personalized estimate based on your vehicle and plug type.
Lifespan: 75,000-100,000 miles
Estimated Total (4 plugs)
$99
Range: $84 to $118
Plugs
$56
Labor (0.5 hrs)
$43
Plug Lifespan
75,000-100,000 miles
DIY Savings
$43
Parts only: $56
You save vs dealership
$47
Spark Plug Types
The plug you choose determines both the parts cost and how long until the next service.
| Type | Cost Per Plug | Lifespan | Best For |
|---|---|---|---|
| Copper | $2 to $5 | 30,000 miles | Older vehicles, short-term fix |
| Single Platinum | $5 to $10 | 60,000 miles | Budget-conscious, wasted spark systems |
| Double Platinum | $8 to $15 | 80,000 miles | Distributor-based ignition systems |
| IridiumMost popular | $8 to $15 | 100,000 miles | Most modern engines, daily drivers |
| Ruthenium | $10 to $20 | 120,000 miles | Performance engines, high mileage keepers |
Iridium costs 3x more per plug than copper but lasts 3x longer. The math favors iridium on any car you plan to keep.
Total Cost by Engine Type
Prices assume iridium plugs at an independent shop. Dealerships run 20 to 40 percent higher.
4 plugs
4-Cylinder
$80 to $200
$40 to $80 labor
Usually top-mounted. Easy access, quick job.
6 plugs
V6
$120 to $350
$80 to $180 labor
Rear bank can be buried. Add $80 to $120 if intake removal needed.
8 plugs
V8
$160 to $500
$100 to $250 labor
More plugs, more labor. Trucks often easier to access than cars.
6 plugs + 6 coils
V6 Coil-on-Plug
$200 to $400
$120 to $200 labor
Smart to replace coil boots at the same time. Coils add $15 to $40 each.
Can You Do This Yourself?
Depends entirely on the engine. Some take 30 minutes. Some require half a day and a second pair of hands.
4-Cylinder, Top-Mounted Plugs
EasyTime: 30 to 45 minutes
- +Remove ignition coils or plug wires one at a time
- +Use a 5/8" or 13/16" spark plug socket with extension
- +Torque to spec (typically 13 to 18 ft-lbs)
- +Anti-seize on the threads if cast iron head, not aluminum
Save $40 to $80 in labor
V6 Buried Rear Bank
HardTime: 2 to 4 hours
- +Front bank is easy. Rear bank requires clearing the firewall
- +Many require removing the intake plenum to reach rear plugs
- +On some Honda V6s, the engine must be tilted forward
- +Use a universal joint socket adapter for awkward angles
Save $100 to $200 in labor if you have the right tools
V8 Truck (Chevy, Dodge, Toyota)
ModerateTime: 1 to 2 hours
- +Most truck V8s have excellent plug access from both sides
- +Work one side at a time so you do not mix up plug wires
- +Check plug gap before installing. Pre-gapped is not always accurate
- +Replace coil boots if they look cracked or oily
Save $100 to $150 in labor
Ford 5.4L Triton V8 (2004 to 2008)
Leave it to a proTime: Unknown. Could go sideways fast
- +Two-piece plug design fills the thread area with carbon over time
- +Plugs snap off in the head at an alarming rate
- +Ford issued a Technical Service Bulletin specifically about this problem
- +A snapped plug requires thread repair or head removal. Budget $800 to $1,500
Not worth the risk. Pay a shop that has the proper extraction tools
When to Replace Spark Plugs
Go by the schedule if the car is running fine. Go by symptoms if something feels off.
By Mileage
Copper plugs Every 30,000 miles
Check your owner manual. Some older cars spec copper.
Single platinum Every 60,000 miles
Common on late 1990s to early 2000s vehicles.
Double platinum Every 80,000 miles
Often found on cars with distributors.
Iridium plugs Every 100,000 miles
Standard on most cars made after 2005.
Ruthenium plugs Every 120,000 miles
Aftermarket upgrade. Not factory spec on most cars.
By Symptoms
Rough idle
Engine shakes or sounds uneven at a stop. A worn plug misfires at low RPM first.
Poor fuel economy
MPG drops noticeably over a few months. Incomplete combustion wastes fuel.
Slow or hesitant acceleration
Car feels sluggish when you press the gas. Often worse in cold weather.
Check engine light (P0300 to P0304)
P0300 = random misfire. P0301 to P0304 = cylinder-specific misfire. Scan the code before guessing.
Hard starting
Engine cranks longer than usual to fire up, especially when cold.
Engine misfires at high RPM
If it only misfires under load or at highway speeds, the plugs are worn down.
Common Questions
How much does spark plug replacement cost for a 4-cylinder?
For a 4-cylinder car with iridium plugs, expect $80 to $200 total at a shop. Parts run $20 to $60 for a set of four iridium plugs. Labor is typically $40 to $80 because the plugs are easy to reach. If you go copper plugs, parts drop to $8 to $20 but you will be back in 30,000 miles.
Why are V6 spark plugs so expensive to replace?
V6 engines have 6 plugs instead of 4, and the rear bank on most transverse-mounted V6s is buried against the firewall. Reaching those three plugs can take 2 to 3 hours of labor because mechanics often need to remove the intake manifold or throttle body. Labor alone on a V6 rear bank can be $150 to $250. Total V6 replacement runs $120 to $400 depending on plug type.
Are iridium spark plugs worth the extra cost?
Yes. Iridium plugs cost $8 to $15 each versus $2 to $5 for copper, but they last 100,000 miles compared to 30,000 for copper. Over 100,000 miles you buy one set of iridium versus roughly three sets of copper. The labor savings alone make iridium worth it since you are paying a shop once instead of three times.
Can I replace spark plugs myself and save money?
On most 4-cylinder engines with top-mounted plugs, yes. You need a spark plug socket, a torque wrench, and about 30 minutes. You save $40 to $100 in labor. However, on V6 engines with a buried rear bank, or any Ford 5.4L Triton V8 from 2004 to 2008, do not attempt it yourself. The Triton is notorious for plugs snapping off in the head, turning a $200 job into a $1,000 head repair.
Get 3 quotes before you commit
Labor rates vary 30 to 50 percent between shops for the exact same job. An independent mechanic will typically beat a dealership by $60 to $120 on a standard spark plug service. Call ahead, tell them your engine size and plug preference, and ask for a total out-the-door price including disposal fees.