15.3in Flavorizer Bars & 17.5in Grill Grates for Weber Spirit 300

In this review we look at the 15.3in porcelain steel flavorizer bars paired with 17.5in cast iron grates, a direct replacement kit aimed at owners of Weber Spirit 300 series and Spirit II E/S-310 gas grills. The bottom line: this kit is for grill owners who want a heavier, longer-lasting set of flavorizer bars and grates that match the original layout but improve heat retention and durability. Installation is straightforward, the fit is accurate for the listed Spirit models, and the thicker 16GA flavorizer bars plus cast iron grates deliver noticeably better sear and heat stability.

Key Features

• Compatibility: Designed to fit Weber GS4 Spirit II 300 series and Spirit E/S 310, 315, 320, 330 models with front control knobs, ensuring a direct replacement for those grills.
• Package Contents: Ships as a set of five 15.3in porcelain steel flavorizer bars and two 17.5in cast iron grates so you replace all cooking surfaces in one purchase.
• Thicker Construction: Flavorizer bars use 1.6mm 16GA steel for improved thermodynamic performance and reduced deformation under heat.
• Snow Point Finish: A high-temperature resistant coating on the bars helps the enamel stay attached longer and contributes a smoky flavor to food.
• Cast Iron Heat Retention: The grates quickly form a high-temperature environment for better searing and more even baking across the cooking surface.
• Care Guidance: The kit includes clear rust-prevention steps so owners can maintain the finish and extend the life of the parts.

Who It's For

This kit is best for Spirit 300 series owners who need a full replacement set and want something heavier and more heat-stable than the original parts. It suits people who grill frequently and value cast iron sear marks and improved temperature control for steaks and vegetables.

It is less well suited for owners of non-listed grill models or those who prefer porcelain-only grates; buyers should compare the listed sizes to their original parts before ordering to ensure fit. If you need replacement parts for a different series or a two-burner model, look elsewhere.

Pros & Cons

Pros

• Heavier 16GA flavorizer bars resist deformation and improve durability compared with thinner originals.
• Cast iron grates provide superior heat retention and produce crisper sear marks.
• Deliver a direct replacement fit for a broad range of Spirit 300 series models, making installation simple.
• Customers report the set is easy to clean and represents strong value for money.

Cons

• Cast iron requires regular seasoning and care to prevent rust, adding maintenance compared with enamel-only grates.
• Fit is specific to listed Spirit models, so it will not work for grills outside those configurations.

Specifications

Our Verdict

For Spirit 300 series owners who want a robust, longer-lasting replacement, this combination of thicker porcelain steel flavorizer bars and cast iron grates is a sensible upgrade. It improves heat retention and searing performance while matching the original layout, making it good value for anyone who grills regularly and will maintain the cast iron with simple seasoning steps.

Frequently Asked Questions

Will these parts fit my Spirit II E-310?
Yes, the kit lists direct compatibility with Spirit II E-310 and similar 300 series models with front-mounted controls; compare measurements to your originals to confirm.

How do I prevent rust on the cast iron grates?
Scrape and season after cleaning, keep dampers slightly open to avoid condensation, use a cover, and apply oil before long-term storage.

Are the flavorizer bars thicker than OEM?
Yes, the bars are 1.6mm 16GA, which is heavier and designed to resist deformation and last longer than typical thinner replacements.