A Guide to Aftermarket Spark Plugs for the 2006-2018 Lexus IS350
Keep your IS350's 3.5L V6 engine running strong by choosing the right spark plugs for your next tune-up.
- Stick to OEM-equivalent iridium spark plugs from Denso or NGK for the best performance and longevity.
- The recommended replacement interval is every 60,000 miles to maintain engine health.
- Replacement is a manageable DIY task, but the driver's side is difficult and requires patience.
- Be cautious of counterfeit plugs online; purchase from trusted retailers to avoid engine problems.
Symptoms of Failing Spark Plugs
When your IS350's spark plugs start to wear out, you'll likely notice a decline in engine performance. Worn plugs can't create a strong enough spark, leading to incomplete fuel combustion. Watch for these common signs:
- Rough Idle: The engine may shake or vibrate more than usual when the car is stopped. A single bad plug can cause a rough idle.
- Engine Misfires: You might feel a hesitation or stumble from the engine during acceleration. This is often accompanied by a flashing check engine light and codes like P0300-P0306.
- Reduced Fuel Economy: One of the first signs can be a drop in your miles per gallon (MPG). Worn plugs can decrease fuel efficiency by as much as 30%.
- Poor Acceleration: The car may feel sluggish or slow to respond when you press the gas pedal.
- Difficulty Starting: Worn-out plugs can make it harder for the engine to turn over, especially in cold weather.
No Recalls or TSBs Found
A search of the National Highway Traffic Safety Administration (NHTSA) database and for Technical Service Bulletins (TSBs) did not find any specific recalls or service bulletins directly related to spark plugs for the 2006-2018 Lexus IS350. However, several recalls exist for fuel system components and airbags for this vehicle range, which are important to be aware of.
Choosing the Right Aftermarket Spark Plugs
When shopping for aftermarket spark plugs, it's important to understand the difference between brands and types. For the Lexus IS350, the original equipment (OEM) plugs are made by Denso and are long-life iridium plugs. This is the benchmark for quality and performance.
Brand Quality Tiers
- OEM-Equivalent (Best Choice): Denso and NGK are the top recommendations. They are the original suppliers for Lexus and provide the best fit and performance. Many owners and mechanics insist on using these brands to maintain factory performance and avoid issues.
- Quality Aftermarket: Brands like Bosch and Autolite offer iridium and double platinum plugs that are a good alternative. They are engineered to meet or exceed OEM specifications and offer a reliable, often more affordable, option.
- Budget-Friendly: Champion offers copper and platinum plugs. While functional, copper plugs have a much shorter lifespan than the iridium plugs your IS350 was designed for and will require more frequent changes. It's generally recommended to stick with iridium plugs for longevity and performance.
A Note on Counterfeits
Be cautious when buying spark plugs from online marketplaces. There are many counterfeit Denso and NGK plugs in circulation. These fake plugs are low quality and can cause engine damage. To be safe, purchase from reputable auto parts retailers.
| Brand Tier | Example Brands | Price Range (Per Plug) | Typical Lifespan |
|---|---|---|---|
| OEM-Equivalent | Denso, NGK | $12 - $20 | 60,000 - 100,000 miles |
| Quality Aftermarket | Bosch, Autolite (Iridium) | $8 - $15 | 60,000 - 100,000 miles |
| Budget-Friendly | Champion, Autolite (Platinum/Copper) | $4 - $10 | 30,000 - 60,000 miles |
Frequently Asked Questions
When should I replace my IS350's spark plugs?
Lexus's official maintenance schedule recommends replacing the spark plugs every 60,000 miles. While modern iridium plugs can sometimes last longer, sticking to this interval is the best way to prevent performance issues.
How many spark plugs does my 2006-2018 IS350 need?
Your Lexus IS350 has a V6 engine, which requires a total of six spark plugs—three for each cylinder bank.
Do I need to gap the new spark plugs?
Generally, no. High-quality iridium spark plugs from brands like Denso and NGK come pre-gapped from the factory for your specific vehicle. Attempting to gap them yourself can damage the delicate iridium tip. Always verify you are purchasing the correct part number for your vehicle.
Is replacing the spark plugs a DIY job?
Yes, it is a feasible DIY job for someone with moderate mechanical experience. The passenger side plugs are relatively easy to access, but the driver's side plugs are more challenging due to wiring harnesses and other components being in the way. It requires patience, a good set of tools including socket extensions and a torque wrench, and careful handling to avoid cross-threading the new plugs.
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Technical Specifications
OEM Part Numbers: 90919-01249 90919-01263
The 2006-2018 Lexus IS350 requires six (6) iridium-tipped, long-life spark plugs. The OEM plugs are typically Denso FK20HBR11. These come pre-gapped and should not be adjusted.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Lexus IS350: