2007 Subaru Impreza Owner's Manual - Page 330

11-38 Maintenance and service Windshield washer fluid Washer fluid level gauge level gauge or the "FULL" mark on the tank. Use windshield washer fluid. If windshield washer fluid is unavailable use clean water. In areas where water freezes in winter, use an anti-freeze type windshield washer fluid. SUBARU Windshield Washer Fluid contains 58.5% methyl alcohol and 41.5% surfactant, by volume. Its freezing temperature varies according to how much it is diluted, as indicated in the following table. Washer Fluid Concentration 30% 50% 100% Freezing Temperature 10.48F (−128C) −48F (−208C) −498F (−458C) If you spray washer fluid on the windshield but the supply of washer fluid appears to diminish, check the level of washer fluid in the tank. CAUTION Never use engine coolant as washer fluid because it could cause paint damage. Remove the washer tank filler cap, then check the fluid level indicated by the level gauge (attached to the inside of the cap). If the level is near the "Low" mark, add fluid until it reaches the "Hi" level on the In order to prevent freezing of washer fluid, check the freezing temperatures in the table above when adjusting the fluid concentration to the outside temperature. If you fill the reservoir tank with a fluid with