Donaldson Receives FAA Approval for New PMA Supplement

MINNEAPOLIS, MN - July 24, 2008 - Donaldson Company (NYSE:DCI), a leading, worldwide manufacturer of filtration systems and parts, announced FAA-PMA approval for several Cessna, Mooney, Piper, Beech and Diamond aircraft.

Laboratory airflow tests show Donaldson filters increase horsepower by increasing airflow compared to aftermarket STC'ed filters. Manufactured using synthetic media, Donaldson filters have deeper pleats and have more media area to provide superior engine protection and improve performance. Other benefits include:

- Designed for 500 flight hours, 3 years of service or 5 cleanings - whichever comes first

- Designed to OEM and FAA-PMA manufacturer specifications

- Meet or exceed FAA fire safety regulation per FAR 25.852 and FAR 23.1107 induction system filters

- Intake filters for over 75 models for Cessna, Beech, Piper, Mooney and others

- Easy installation and maintenance, no removable parts or messy oil

To learn more about filters for the general aviation market, visit or contact us at 866-323-0394.

About Donaldson Company

Donaldson is a leading worldwide provider of air and liquid filtration systems and replacement parts that improve people's lives, enhance our Customers' equipment performance and protect our environment. We are a technology-driven company committed to satisfying our Customers' needs for diesel engine equipment and industrial filtration solutions through innovative research and development, superior technology, and global presence. Our almost 13,000 employees contribute to the company's success by supporting our Customers at more than 100 sales, manufacturing, and distribution locations around the world.

Donaldson is a member of the S&P MidCap 400 and Russell 1000 indices, and our shares trade on the NYSE under the symbol DCI. Additional information is available at