Cummins has test strips available, but only in a 50 pack.<br/><br/>The local Cummins dealer here does not have any ES Compleat OAT test strips in house, and their lead mechanic<br/>says he goes by appearance and feel (between his fingers). I took a sample of my coolant to him and he did just<br/>those two things, saying that as long as the OAT wasn't diluted by adding anything it's...