NGK Ruthenium HX TR5AHX Spark Plugs for C5 Corvette LS1
NGK Ruthenium HX TR5AHX spark plugs, stock number 94567, fit the 1997–2004 C5 Corvette with the LS1 5.7L engine in stock configuration. This offer includes eight spark plugs supplied as two manufacturer packs of four for a full V8 spark-plug replacement.
For an LS1-powered C5 that sees regular road use, Ruthenium HX brings a double-fine-electrode firing design to a complete plug replacement. Its ruthenium-alloy center tip faces a fine platinum ground tip, helping the spark ignite the mixture with less interference around the firing point. The result is a high-ignitability design suited to maintaining your stock 5.7L engine.
Product Details
- Exact plug identity: NGK 94567, design code TR5AHX, Ruthenium HX.
- Double Fine Electrode design: Fine ruthenium-alloy center and platinum ground firing tips support high ignitability.
- Precious-metal firing surfaces: The ruthenium-alloy center tip provides resistance to wear during repeated sparking.
- Complete V8 quantity: Eight matching plugs in two four-packs; select order quantity one for one engine.
- Included components: Spark plugs only. Plug wires and ignition coils are separate and are not included.
Benefits
- High-ignitability construction: Opposed fine tips help the spark initiate combustion of the air-fuel mixture.
- Wear-resistant firing surface: The ruthenium-alloy center electrode helps resist wear over repeated ignition cycles during regular street use.
- Complete LS1 maintenance: Renew all eight spark plugs together for regular road use in your C5 coupe, convertible or Fixed Roof Coupe.
Important Notes
- Body-style years: Match your LS1 coupe to 1997–2004, convertible to 1998–2004, or Fixed Roof Coupe to 1999–2000. Those body-style dates keep the service set matched to your C5.
- Fixed Roof Coupe selection: A 1999–2000 FRC retains the 5.7L LS1 fitment covered here. Confirm the engine in the car when ordering, especially if its service history includes an engine replacement.
- Installation gap: Use 0.040 inch (1.02 mm) for this stock LS1 fitment. Measure every plug before installation; do not assume the gap supplied in the box is the required vehicle setting.
- Protect both firing tips: Check with a round-wire or pin gauge. Any adjustment must move only the ground electrode without pressure on the center tip; ask a qualified installer if unsure.
- Installation care: Use clean, dry threads without anti-seize and follow the vehicle tightening specification. Have your engine builder or tuner confirm plug requirements if the engine has been modified.
CORVETTE COMPATIBILITY
- 1997–2004 C5 Corvette LS1 coupe
- 1998–2004 C5 Corvette LS1 convertible
- 1999–2000 C5 Corvette LS1 Fixed Roof Coupe
- LS1 5.7L V8, stock configuration
- Manual and automatic transmissions; FRC manual
Why Buy from Custom Corvette Accessories?
At Custom Corvette Accessories, we’re Corvette owners ourselves, and we offer one-on-one customer service to help you choose parts for your car. Have a question about NGK 94567 TR5AHX Ruthenium HX spark plugs for your C5 Corvette LS1? Contact us for personal help before you order.
✅ In-stock items ship in 1–2 business days via Standard Ground.
✅ Free shipping items are available in the Continental US only.
✅ Custom quotes available for 2-Day, Next Day, or Saturday delivery.
✅ Custom or backordered items ship as soon as available.
