https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCEQFjAA&url=http%3A%2F%2Fwww.norosion.com%2Fevanstest.htm&ei=K169VKbVCpHB7AbOqoGQCw&usg=AFQjCNGlaEt7KitnXaqjcmjMaCiftvNsGQ&sig2=xLIEwQGlyitYbitKO0-O0A
Optimum time for me fill the engine with this stuff but think im still sticking with good ol fashioned water.