If a vacuum cleaner has a powerful motor, it means that it has good amperage. Good amperage doesn’t mean that the suction power will be powerful. The suction power of a vacuum cleaner depends on its design, filtration specifications, and airflow. Airflow is usually measured in cubic feet of air per minute (CFM). Now, this is a value that reflects how powerful suction is. Vacuums with a high CFM have the best suction power.