Vehicle Compatibility

The Mishimoto MMRAD-MIA-99 is a direct-fit radiator for:

Mazda MX-5 Miata

• 1999 Mazda Miata
• 2000 Mazda Miata
• 2001 Mazda Miata
• 2002 Mazda Miata
• 2003 Mazda Miata
• 2004 Mazda Miata
• 2005 Mazda Miata

Transmission Compatibility

• Manual transmission models

Always verify fitment before ordering.

Key Specifications

The Mishimoto radiator features:

• Overall Dimensions: 26.2″ x 17.2″ x 2.55″
• Core Size: 12.8″ x 22.17″
• Two-Row Aluminum Core
• Core Thickness: 2.05″
• Inlet Diameter: 1.25″
• Outlet Diameter: 1.25″
• Tank Wall Thickness: 0.08″
• TIG-Welded Aluminum Construction
• High-Pressure Radiator Cap Included
• Magnetic Drain Plug Included

These specifications provide a substantial upgrade over the factory cooling system.

Up to 30 Percent Greater Cooling Efficiency

One of the biggest advantages of the Mishimoto radiator is its increased cooling capacity.

According to Mishimoto, the MMRAD-MIA-99 can provide up to 30 percent greater cooling efficiency compared to the factory radiator.

Benefits include:

• Lower coolant temperatures
• Improved temperature stability
• Reduced heat soak
• Better track-day performance
• Increased engine protection

Whether you’re attacking autocross cones or spending a day at the road course, maintaining consistent temperatures helps preserve both performance and reliability.

Full Aluminum Construction

Unlike the factory radiator that relies on plastic end tanks, the Mishimoto radiator utilizes fully aluminum construction.

Advantages include:

Increased Durability

Aluminum tanks eliminate one of the most common failure points found in aging OEM radiators.

Better Heat Transfer

Aluminum dissipates heat efficiently, helping coolant temperatures remain more stable under load.

Long-Term Reliability

A quality aluminum radiator is often considered a preventative maintenance upgrade for older Miatas.

Dual-Core Design

The Mishimoto radiator utilizes a thicker dual-core design compared to many factory cooling systems.

Benefits include:

• Increased coolant capacity
• Improved heat exchange
• Better cooling during sustained high-RPM driving
• More efficient temperature control

For modified Miatas, this added cooling capacity becomes even more valuable.

TIG-Welded Construction

The radiator features fully TIG-welded aluminum tanks and core assemblies.

This manufacturing process offers:

• Strong weld integrity
• Improved pressure resistance
• Enhanced durability
• Professional motorsports-grade construction

The polished aluminum finish also looks right at home in a clean engine bay.

Included High-Pressure Radiator Cap

Mishimoto includes a high-pressure radiator cap with the kit.

Benefits include:

• Increased cooling system pressure
• Higher coolant boiling point
• Improved cooling efficiency
• Added value compared to basic replacement radiators

Magnetic Drain Plug

A magnetic drain plug is also included.

This feature helps capture metallic particles circulating through the cooling system and provides a convenient inspection point during maintenance.

It’s a small detail that enthusiasts appreciate.

Perfect for Modified Miatas

The MMRAD-MIA-99 is especially beneficial for:

• Turbocharged Miatas
• Supercharged Miatas
• Autocross cars
• Road course builds
• Track-day enthusiasts
• Daily drivers in warm climates

As horsepower increases, cooling demands increase as well.

A quality aluminum radiator helps create a stronger foundation for future modifications.

Installation

One of the best features of this radiator is its direct-fit design.

Installation typically requires:

• Draining coolant
• Removing the factory radiator
• Swapping hoses and cooling components
• Refilling and bleeding the cooling system

No cutting or fabrication is normally required.

Mishimoto Lifetime Warranty

Every Mishimoto radiator is backed by the company’s lifetime warranty.

This warranty provides additional confidence and demonstrates Mishimoto’s commitment to long-term durability and product quality.

Final Verdict

The Mishimoto MMRAD-MIA-99 Performance Aluminum Radiator is one of the smartest cooling upgrades available for the 1999-2005 Mazda Miata. With improved cooling efficiency, durable all-aluminum construction, dual-core design, and direct-fit installation, it offers substantial benefits for both stock and modified vehicles.

Whether you’re preserving a beloved weekend cruiser, building a turbocharged street car, or preparing for your next track day, the MMRAD-MIA-99 provides the cooling performance needed to keep your NB Miata running at its best.