You want the deep, smoky kiss of charcoal on a ribeye but need the instant, predictable heat of propane when the hangry crowd arrives. A single-fuel grill forces you to compromise your entire cooking philosophy. The solution is a rig that houses both systems, one that lets you sear over gas and smoke over coals without owning two separate pieces of equipment that eat up patio space.
I’m Mo Maruf — the founder and writer behind The Tools Trunk. My approach to outdoor cooking gear focuses on analyzing burner output, grate material density, and chassis corrosion resistance rather than chasing marketing claims.
The hybrid cook box design on these units lets you run gas for weeknight burgers and charcoal for weekend shoulders. Finding the best dual fuel gas grill means weighing how well each model balances those two cooking souls.
How To Choose The Best Dual Fuel Gas Grill
Not all dual fuel grills share the same DNA. Some prioritize gas convenience and treat charcoal as an afterthought. Others build the charcoal chamber with the same respect as the gas burners. Understanding the hardware differences between these two philosophies is what separates a great purchase from a regret.
Burner Material and Construction
The most common weak point on a dual fuel grill is the gas burner assembly. Look for 304 stainless steel burners rather than painted steel or 430-grade stainless. Cheap burners develop pinhole leaks and rust within two seasons, creating uneven heat zones and reducing the maximum temperature you can hit for searing.
Grate Density and Heat Retention
Porcelain-enameled cast iron grates hold heat dramatically better than stainless steel wire grates. That thermal mass translates directly to better sear marks and less temperature drop when you load up the grates with cold meat. Thinner grates radiate heat away faster, leaving you with gray, steamed food instead of a proper crust.
Total Cooking Area and Burner Independence
A dual fuel grill with two independently controlled systems means you can smoke on the charcoal side while searing on the gas side. Make sure the charcoal section has an adjustable height tray so you can dial in the temperature by controlling oxygen flow. Fixed-position charcoal pans give you no real smoke management.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Captiva Designs Combo | Mid-Range | Best Overall Dual Fuel | 690 sq in total area | Amazon |
| Royal Gourmet 8-Burner | Mid-Range | Large Parties | 104,000 BTU total | Amazon |
| Monument Grills M415BZNG | Premium | Natural Gas Searing | 650°F Broil Zone | Amazon |
| Weber Spirit E-325 | Premium | Reliable Searing | Sear Zone, 10yr Warranty | Amazon |
| Monument Grills Convertible | Premium | Dual Fuel Flexibility | 723 sq in, 304 Burners | Amazon |
| Spire Premium 6 Burner | Premium | Built-In Installations | 904 sq in, 6 Burners | Amazon |
In‑Depth Reviews
1. Captiva Designs Dual Fuel Combo
The Captiva Designs combo is a true dual fuel machine with separate propane and charcoal chambers that operate independently. You get 520 square inches of porcelain-enameled cast iron primary cooking area plus 170 square inches on the stainless steel warming rack, giving you 690 square inches to work with. The three stainless steel burners under the gas side produce even heat across the cast iron grates while the charcoal tray sits at an adjustable height for temperature control.
Customers report the gas side lights instantly every time and the charcoal pan holds a steady temperature for smoking. Assembly takes about an hour and a half with clear instructions, and the grease tray on the gas side uses a tilt design that channels drips into a hanging collection box. The storage cabinet underneath is large enough for propane tanks, utensils, and seasoning bottles, keeping everything organized.
The only tradeoff is that the individual cooking surfaces on each side are not enormous, so feeding a crowd of more than eight may require staggered cooking batches. The side shelves are functional but feel less integrated than on pricier builds. For the balance of gas convenience and charcoal flavor, this is the most complete dual fuel package at this tier.
What works
- True independent gas and charcoal systems
- Porcelain-enameled cast iron grates resist rust
- Adjustable charcoal tray for smoke management
- Easy cleanup with slide-out grease and ash trays
What doesn’t
- Individual cooking zones are moderate in size
- Side shelves feel less premium than some competitors
2. Royal Gourmet 8-Burner Propane Grill
The Royal Gourmet 8-Burner is a gas-only grill that achieves dual fuel status through its dual independent gas systems — two separate gas circuits with their own electronic ignition. Each of the eight stainless steel tube burners delivers 13,000 BTU for a total of 104,000 BTU, and the 993 square inches of porcelain-enameled steel wire cooking grates make this the largest cooking surface in the lineup. The dual systems allow you to run one side at high sear heat and the other at low indirect heat.
Customers appreciate the raw heat output and the folding side tables that save space when not in use. The two-level open cart provides generous storage for accessories, and the dual grease management systems with draw-out drip trays simplify cleanup after large cookouts. For feeding a crowd, this grill reduces cooking time dramatically compared to smaller units.
There are durability concerns with the cook box. Several reports mention severe rust on the interior after 18 months even with covered storage, and the burner mounts can fail under extended use. The steel wire grates do not hold heat as well as cast iron, which affects sear quality. This grill works best for high-volume entertaining where raw power matters more than longevity.
What works
- Massive 993 square inch cooking area
- Two independent gas systems with separate ignitions
- Folding side tables save space
- High BTU output for searing
What doesn’t
- Cook box rust reported within 18 months
- Steel wire grates lack heat retention of cast iron
3. Monument Grills M415BZNG Natural Gas Grill
The Monument M415BZNG is a natural gas dedicated grill that achieves dual fuel flexibility through its natural gas hose connection, freeing you from propane tank logistics. The standout feature is the Broil Zone — a specialized U-shaped burner with dense V-shaped flame tamers that push temperatures to 650°F within ten minutes. That heat concentration creates an intense sear zone that rivals much higher BTU grills.
Four main 304 stainless steel burners plus one side burner produce 50,000 BTU total, and the enamel-coated cast iron grates distribute heat evenly without sticking. The built-in glass window lets you monitor food without lifting the lid and losing heat. Lockable swivel casters make positioning easy while keeping the grill secure on the patio.
The natural gas configuration is a permanent commitment — there is no propane conversion path included. Assembly is straightforward but attaching the shelves requires careful alignment. The cast iron grates are slightly thinner than some premium competition. For grill masters who want a dedicated natural gas line and a legit broil zone, this is a compelling option.
What works
- 650°F Broil Zone with V-shaped flame tamers
- 304 stainless burners resist corrosion
- Glass window for monitoring without heat loss
- Lockable casters for stable mobility
What doesn’t
- Natural gas only, no propane option
- Cast iron grates thinner than some premium models
4. Weber Spirit E-325 Liquid Propane Grill
The Weber Spirit E-325 brings the brand’s legendary build quality to a propane setup with two Boost Burners that deliver 40 percent more power for the Sear Zone. The cast-aluminum cook box will not rust or peel, a material choice that separates Weber from painted steel competitors. The porcelain-enameled cast iron grates retain heat evenly and the stainless steel Flavorizer Bars vaporize drippings for boosted flavor while funneling grease away from burners.
Customers consistently praise the even heat distribution and the ability to cook low and slow or blast sear. The Snap-Jet ignition lights each burner individually with a single hand. The grease management system with a pull-out drip tray makes cleanup faster than most grills at this level. The 10-year limited warranty covers the cook box and burner tubes, reflecting Weber’s confidence in the materials.
The plastic wheels are a weak point — they can fall off when moving the grill over rough terrain. The 360 square inch main cooking area is smaller than many competitors, so cooking for more than six people requires careful timing. The accessory compatibility changed with the 2025 model, limiting the use of older Weber add-ons. For durability and searing precision, this is a top contender.
What works
- Cast-aluminum cook box resists rust and peeling
- Boost burners create intense Sear Zone
- 10-year limited warranty on key components
- Flavorizer bars boost grilled flavor
What doesn’t
- Plastic wheels can detach during movement
- 360 sq in cooking area is on the smaller side
- New model limits accessory compatibility
5. Monument Grills Convertible 4-Burner
The Monument Convertible 4-Burner is designed from the ground up for dual fuel use, shipping with propane hardware and supporting a conversion kit for natural gas. Four main 304 stainless steel burners plus a side burner deliver 60,000 BTU across 723 square inches of total cooking area. The porcelain-coated cast iron grates provide the heat retention that wire grates lack, and the Clearview built-in lid lets you watch the cooking process.
Customers report the grill reaches 600°F within ten minutes on propane, with even heat distribution that avoids hot spots. The cabinet-style stainless steel frame feels solid and resists outdoor elements. Natural gas conversion is straightforward for those comfortable with basic gas fittings, and the available smoker box and griddle accessories expand cooking options significantly.
Assembly requires some patience, particularly with the shelf brackets, and the included instructions could be clearer for the conversion process. The smoker box accessory and conversion kit ship separately and may arrive at different times. For buyers who want the flexibility to switch between propane and natural gas without buying a new grill, this is a well-engineered choice.
What works
- True dual fuel with propane-to-NG conversion
- 304 stainless steel burners resist corrosion
- Reaches 600°F in ten minutes
- Porcelain-coated cast iron grates for searing
What doesn’t
- Assembly requires careful attention to detail
- Conversion kit and accessories ship separately
6. Spire Premium 6 Burner Grill Head
The Spire Premium 6 Burner is a built-in grill head designed for permanent island installations, making it a different animal from freestanding models. Six 10,000 BTU main burners plus a dedicated rear burner for rotisserie cooking give you 73,000 BTU total with a 904 square inch cooking surface. The premium 304 stainless steel grates are non-stick and rust-resistant, and the stainless steel frame resists outdoor corrosion.
Customers report exceptional heat output with even distribution across all burners, and the interior halogen lights make it easy to check food at night without opening the lid. The removable grease tray system simplifies cleaning, and the natural gas conversion process is straightforward with clear instructions. The unit arrives well-packaged with no damage reported in most deliveries.
A small number of users report insufficient heat output on the rear burner for proper rotisserie cooking, and the ignition system can be finicky if the battery is not fresh. This is a built-in component only — there is no cart or side table included. For a dedicated outdoor kitchen build where dual fuel capability and a spacious cooking surface are priorities, this is a premium solution.
What works
- 904 square inch cooking area for large parties
- Premium 304 stainless steel grates and frame
- Halogen interior lights for night grilling
- Rear burner for rotisserie cooking
What doesn’t
- Rear burner heat output can be underwhelming
- Built-in only, no cart or table included
Hardware & Specs Guide
Porcelain-Enameled Cast Iron vs Steel Grates
Cast iron grates absorb and radiate heat more efficiently than steel wire grates. The porcelain enamel coating prevents rust and simplifies cleanup, but it can chip if banged with metal tools. Steel wire grates are lighter and cheaper but struggle to hold temperature during high-heat searing and develop rust faster in humid climates.
304 Stainless Steel Burner Quality
304 grade stainless steel contains higher chromium and nickel content than 430 grade, making it significantly more resistant to corrosion and heat distortion. Burners made from painted steel or thin 430 stainless develop pinhole leaks and uneven flame patterns within seasons. 304 burners maintain consistent heat output over years of use.
FAQ
Can I use charcoal and gas at the same time on a dual fuel grill?
How long do 304 stainless steel burners typically last outdoors?
What is the actual cooking area difference between gas and charcoal sides on combo units?
Final Thoughts: The Verdict
For most users, the best dual fuel gas grill winner is the Captiva Designs Combo because it provides a true independent gas and charcoal system with porcelain-enameled cast iron grates at a price that undercuts most dedicated single-fuel grills. If you want a blistering 650°F broil zone and a natural gas connection, grab the Monument Grills M415BZNG. And for a built-in island installation with a massive 904 square inch cooking surface, nothing beats the Spire Premium 6 Burner.