A system and method for generating a change in pressure proportional to fluid viscosity is disclosed herein. The system can comprise a first pilot stream, a second pilot stream, and a pressure sensing device that reads a differential pressure across a first junction on the first pilot stream and a second junction on the second pilot stream. The first junction is between a first section having a first predominant pressure loss characteristic, and a second section having a second predominant pressure loss characteristic. Similarly, the second junction can be between a third section having a third predominant pressure loss characteristic and a fourth section having a fourth pressure loss characteristic.