Why This Intake Delivers
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Replaces the restrictive factory airbox and filter with a high-flow synthetic Dryflow filter for outstanding airflow and filtration.
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Filter is relocated to a cooler intake zone (inside front bumper on driver’s side) to reduce intake‐air temperature.
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Mandrel-bent aluminum tubing for smoother, less turbulent airflow compared to factory plastic snorkel.
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Lifetime limited warranty from AEM and reusable oil-free filter for long service life.
AEM Air Intake Systems are designed to produce massive horsepower and torque gains as well as better engine sound when used as a replacement for the factory airbox and air filter. AEM intake systems are designed, tuned, and dyno-tested to fit specific cars and trucks.
Performance Benefits
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Sharper throttle response thanks to freer airflow.
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Slight bump in power and torque due to improved breathing (especially useful in high-rev range on the NC2 .0).
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Enhanced induction sound gives the Miata more character under load.
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Long-term savings: reusable filter means fewer recurring parts.
These air intakes usually include an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration, and performance while allowing easy oil-free cleaning. Most AEM intake systems use mandrel-bent aluminum intake tubes, powder coated heat shields, and high quality hardware designed to reduce restriction and reduce intake temperature.
Installation Notes
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Install time: ~1 hour for most mechanically-inclined users, assuming standard tools.
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Ensure vehicle is indeed the 2.0L Miata (not the 1.8L or swapped engine) to guarantee fitment.
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After installation, check for proper clearance, filter positioning (avoid contact with splash guard or debris ingress) and ensure all clamps and sensor connections are secure.
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Verify legality: some AEM C.A.S. kits may have California emissions restrictions—check your local regs.
The design and components of each intake system vary so consult the installation instructions for more information on the contents of each part number. AEM manufactures a variety of intake kit styles including short ram intakes, cold air intakes, dual-chamber intakes, Brute Force intakes for trucks and SUV’s, and Brute Force HD intakes for diesel applications.
Final Verdict
For owners of the 2006-2009 Mazda MX-5/Miata 2.0L, the AEM 21-640C C.A.S. intake is a smart performance upgrade. It improves airflow, sound and throttle feel without being overkill. A quality bolt-on for the enthusiast who wants better performance while retaining clean fitment.
Great Quality and Look! –
AEM is a quality brand that I’ve always trusted on my cars. This definitely adds power where it counts, and feel more efficient than most CAI systems on the market. 6th gear on the freeway has way better passing power with this little upgrade, that alone is a reason to buy.
R. Rahman –
It’s a good first upgrade that’s guaranteed to be worth for the improved sound and fuel efficiency. The icing is the smoother acceleration in the 3500+ rpm territory
Tyler Wood –
Installed this on my 06 Miata Autocross car. Improved Throttle feel but it’s nothing crazy. Well made and installation is a snap. YOU DO NOT NEED TO REMOVE THE CRASH BAR. Just remove the bumper and fish it gently behind the crash bar.
Eric –
I installed this intake a week or two ago. My car is no where near stock, it has Goodwin Racing Roadstersport full street exhaust and a tune. The exhaust made the throttle response a little sharper, and made the engine growl more under hard acceleration. I used an OBDII logger and it indicated that intake temperature is only a few degrees above ambient, and quickly returned to that level from heat soak during start and stop traffic. The water sock prevents any sort of hydro lock. I brought the car through a touchless car wash and the engine cranked with no problem at all.The build quality is top notch, this IS the same as the Mazdaspeed intake, just cheaper in price.
Kevin Mendoza –
Amazing product made the acceleration way more aggressive. Very recommend it. Don’t cheap out on other cold air intakes. This is the best one on the market.
David Cantrell –
Good product. Easy to read directions with good pictures.
limey1970 –
As with every AEM product this fit perfectly and did not result in any check engine light. Worth the money.
Kevin Marc Roberts –
It took a little less than three hours to install in my 2006 MX-5. I had a friend help. I’m an accountant, and he’s a bartender and it was quick. two sets of hands def. make it easier, but it’s not impossible to do alone. My car sounds great with it installed and my gas mileage might have gone up a little, but I can’t guarantee that because I drive a little faster now with this cool intake installed.