Perma Cool 19115 16inch High Performance Electric Fan

In choosing an electric fan for primary cooling, four cylinder engines generally require 1,600 cubic feet per minute (CFM) minimum. Six cylinder engines generally require 2,000 CFM minimum, small cubic inch eight cylinder engines require 3,000 CFM and large cubic inch eight cylinder engines require a minimum of 4,500 CFM. Recommendations are based on stock engines and regular driving conditions. CFM estimates are based on the electric fan mounted behind the radiator in a pulling configuration. Electric fans mounted in front of the radiator, in a pushing configuration, are only 80% as effective.