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Spearhead Max Thrust Engine Air Filter | Fits 2016-17 Crosstrek, 2009-18 Forester, 2008-16 Impreza, 2005-19 Legacy/Outback, 2008-14 Tribeca, 2012-21 WRX/STI | OEM Fit & High Dust Capacity (MT-997)

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Availability: In Stock.
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Arrives Wednesday, Apr 15
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Size: MT-997 1-Pack


Features

  • Experience an Obvious Difference: Whether you are noticing a delay in acceleration, less than average gas mileage or own a higher mileage vehicle, our Max Thrust engine air filters will provide a clear and cost effective upgrade over stock performance
  • Trap 2X Dirt vs. Standard Air Filters: Our unique Hex-D pleat design creates maximum holding capacity for trapping unwanted dirt and debris without compromising airflow like standard air filters thanks to multiple layers of progressively finer filter media that allows air to flow freely even when the filter is dirty
  • Increased Power and Mileage up to 15K Miles: Deficient airflow can cause your engine to work twice as hard to suck in the minimum amount of air it needs to perform regularly, resulting in poorer gas mileage and lower power efficiency; Max Thrust air filters are designed to give your engine a break by delivering as much clean air as it needs to perform optimally up to 15K miles
  • Do It Yourself: Replacement for Crosstrek (2016-17, does not fit Hybrid), Forester (2009-18, does not fit 2008 Forester), Impreza (2008-16, fits all trims), Legacy (2005-19), Outback (2005-19), Tribeca (2008-14), WRX (2012-21), WRX STI (2013-18, does not fit 2018 Type RA), make sure to enter your year, make and model above to check fitment; the engine air filter is an easy replacement that can save you money at the repair shop
  • Better Filter than Your Last One: We know its hard to choose from so many different brands carrying the same product; we make it easier for our customers to decide with a simple promise

Description

Compatible Model and Year List (please verify using Amazon’s ‘My Garage’) Crosstrek (2016-2017, does not fit Hybrid), Forester (2009-2018, does not fit 2008 Forester), Impreza (2008-2016, fits all trims), Legacy (2005-2019), Outback (2005-2019), Tribeca (2008-2014), WRX (2012-2021), WRX STI (2013-2018, does not fit 2018 ‘Type RA’) About Spearhead We are a family-owned operation leveraging 30 years of automotive parts sourcing for some of the largest automotive aftermarket suppliers in the United States to build a brand customers can trust to find the best products at the best prices. Cross Reference Part No.’s Spearhead: MT-997Fram: CA9997 Did you know this about engine air filters? An engine air filter will pay for itself with the money you save at the gas pump…a new engine air filter can increase your vehicle’s MPG by up to 10%.There’s no better or cheaper investment you can make to extend the life of your vehicle than regularly replacing your engine air filter every 12-15K miles. When is the ‘right’ time to replace my engine air filter? Warning/Engine Light Turns On: A light will appear on vehicles equipped with airflow sensors.Noticeably Slower Acceleration: If your vehicle is slow to accelerate or responds poorly to pedal control this can mean your engine isn't receiving enough air to perform normally.Reduced Fuel Economy: The less oxygen an engine consumes, the more fuel it will burn – causing fuel economy to go down.Up to 15K Miles or 1 Year: If you don’t remember the last time you replaced your engine air filter it’s time to change it out! Questions or Concerns? If you have any questions/concerns, message us using Amazon’s ‘contact seller’ form.

Product Grade: Replacement Part


Brand: SPEARHEAD


Fit Type: Vehicle Specific Fit


OEM Part Number: CA9997


Shape: Square


Manufacturer: ‎Spearhead


Brand: ‎SPEARHEAD


Item Weight: ‎8.4 ounces


Package Dimensions: ‎8.94 x 8.82 x 1.77 inches


Item model number: ‎MT-997


Manufacturer Part Number: ‎MT-997


OEM Part Number: ‎CA9997


Date First Available: June 25, 2019


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Apr 15

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • ⭐️⭐️⭐️⭐️⭐️ Excellent Air Filter – Restored MPG & Acceleration!
Size: MT-450 1-Pack
This Spearhead MPG Defense Max Thrust Engine Air Filter (MT-450) is a fantastic upgrade over stock filters! Installation was super easy, and the OEM fit was perfect for my 2015 Nissan Altima 2.5L—it dropped right in with no issues. Since replacing my old filter, I’ve noticed improved throttle response and smoother engine operation. My gas mileage even went up by 2 MPG, which is a great bonus! The Hex-D pleat design truly traps more dirt while maintaining strong airflow. For just $13.99, the quality and performance exceed expectations—better than higher-priced options. If you want a simple, cost-effective way to enhance fuel efficiency and acceleration, this is a must-buy! Highly recommend! 🚗🔧✅ ... show more
Reviewed in the United States on May 29, 2025 by El Boomer

  • Love it! Fit prefectly!
Size: MT-295 1-Pack
Really thankful this exists; it's cheap and easy to install, helping me save unnecessary money at the dealership.
Reviewed in the United States on January 19, 2026 by Kennedy

  • Great filter at a great price.
Size: MT-261 1-Pack
Good quality, seems to improve milage (+2mpg hwy) and throttle response.
Reviewed in the United States on February 26, 2026 by Dean

  • Durable Engine Air Filter with Solid Performance
Size: MT-997 1-Pack
This engine air filter is well-constructed and fits a variety of vehicles, making it versatile for general use. It effectively helps keep the engine clean by filtering out dust and debris, supporting overall performance and longevity. Installation is straightforward, and the filter feels sturdy and durable. The only minor consideration is that airflow may feel slightly restricted compared to OEM filters, but it performs well for most driving conditions. Overall, a reliable, high-quality air filter that delivers solid performance and protection. A good choice for routine maintenance and engine care. ... show more
Reviewed in the United States on October 16, 2025 by Jay

  • Fit like a glove
Size: MT-113 1-Pack
Absolutely thrilled with this purchase! The product exceeded my expectations in every way—great quality, well-made, and performs exactly as described. Shipping was fast, and the packaging ensured everything arrived in perfect condition. I appreciate the attention to detail and thought put into this. Would definitely recommend to anyone looking for something reliable and worth every penny. I’m beyond satisfied and would definitely buy again. ... show more
Reviewed in the United States on January 27, 2025 by Dakota Ray Ison

  • Good Filter, Great Price!
Size: MT-348 1-Pack
Great alternative to an OEM filter and a lower price!
Reviewed in the United States on November 18, 2025 by Dave

  • OEM quality
Size: MT-943 1-Pack
I have a 2021 Kia Sedona and this fits perfectly. I think some people complain because they don’t understand how the locking bars work
Reviewed in the United States on February 19, 2026 by SouthernBell

  • Great Air Filter
Size: MT-413 1-Pack
So far I really like this air filter. It can be installed in minutes, has a nice thick rubber seal, and I have already experienced an increase in gas mileage. I do believe it provides better airflow than my old filter and I would definitely purchase again.
Reviewed in the United States on September 30, 2025 by Nursing Life

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